GIGABYTE X99-SLI Motherboard Review

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It wasn’t too long ago that GIGABYTE announced their X99 Champion Series motherboards. Today, we’ll have a look at the newest addition to the X99 Championship family, which is called the X99-SLI. At first glance, the GIGABYTE X99-SLI seems to be a feature-rich motherboard packed with the GIGABYTE enthusiast-level options we’ve come to expect on their higher end offerings. Let’s dive in and see if GIGABYTE has a motherboard worthy of your hard earned dollar.

Specifications and Features

Looking at the specifications below, it’s pretty easy to tell the X99-SLI has plenty of options for the vast majority of users. The motherboard is built on an ATX form factor PCB and offers plenty of connectivity through a plethora of SATA, USB, and M.2 ports. DDR4 XMP support for memory speeds up to 3333 MHz is supported as well. Using Intel LAN and the Realtek ALC1150 CODEC are about as good as it gets for those two onboard solutions. Depending on the CPU installed, up to 4-way CrossFire/SLI is supported.

GIGABYTE X99-SLI Specifications
  • Support for Intel® Core™ i7 processors in the LGA2011-3 package
  • L3 cache varies with CPU
  • Intel® X99 Express Chipset
  • 8 x DDR4 DIMM sockets supporting up to 64 GB of system memory
  • 4 channel memory architecture
  • Support for DDR4 3333(O.C.) / 3200(O.C.) / 3000(O.C.) / 2800(O.C.) / 2666(O.C.) / 2400(O.C.) / 2133 MHz memory modules
  • Support for non-ECC memory modules
  • Support for Extreme Memory Profile (XMP) memory modules
  • Support for RDIMM 1Rx8/2Rx8/1Rx4/2Rx4 memory modules (operates in non-ECC mode)
  • Realtek ALC1150 CODEC
  • High Definition Audio
  • 2/4/5.1/7.1 Channel
  • Support for S/PDIF Out
  • Intel GbE LAN Chip (10/100/1000 Mbit)
Expansion Slots
  • 2 x PCI Express x16 slots, running at x16 (PCIE_1/PCIE_2)
  • 2 x PCI Express x16 slots, running at x8 (PCIE_3/PCIE_4)
  • 3 x PCI Express x1 slots
  • 1 x M.2 Socket 1 connector for the wireless communication module (M2_WIFI)
  • Support for 4-Way/3-Way/2-Way AMD CrossFire™/NVIDIA® SLI™ technology

  • 1 x M.2 PCIe connector
    (Socket 3, M key, type 2242/2260/2280 SATA & PCIe x2/x1 SSD support)
  • 1 x SATA Express connector
  • 6 x SATA 6Gb/s connectors (SATA3 0~5)
  • Support for RAID 0, RAID 1, RAID 5, and RAID 10


  • 4 x SATA 6Gb/s connectors (sSATA3 0~3), supporting IDE and AHCI modes only

  • 4 x USB 3.0/2.0 ports (available through the internal USB header)
  • 8 x USB 2.0/1.1 ports (4 ports on the back panel, 4 ports available through the internal USB headers)

Chipset + Renesas®uPD720210 USB 3.0 Hub:

  • 4 x USB 3.0/2.0 ports on the back panel
Internal I/O
  • 1 x 24-pin ATX main power connectorŠ
  • 1 x 8-pin ATX 12V power connector
  • 1 x PCIe power connector
  • 1 x M.2 Socket 3 connector
  • 1 x SATA Express connector
  • 10 x SATA 6Gb/s connectors
  • 1 x CPU fan header
  • 1 x water cooling fan header (CPU_OPT)
  • 3 x system fan headers
  • 1 x front panel header
  • 1 x front panel audio header
  • 2 x USB 3.0/2.0 header
  • 2 x USB 2.0/1.1 headers
  • 1 x Trusted Platform Module (TPM) header
  • 1 x Thunderbolt add-in card connectorŠ
  • 1 x Clear CMOS jumper
Back Panel Connectors
  • 1 x PS/2 keyboard port
  • 1 x PS/2 mouse port
  • 4 x USB 3.0/2.0 ports
  • 4 x USB 2.0/1.1 ports
  • 1 x optical S/PDIF Out connector
  • 1 x RJ-45 port
  • 5 x audio jacks (Center/Subwoofer Speaker Out, Rear Speaker Out, Line In/Mic In, Line Out)
  • 2 x Wi-Fi antenna connector holes
I/O Controller
  • iTE® I/O Controller Chip
H/W Monitoring
  • System voltage detection
  • CPU/System/Chipset temperature detection
  • CPU/CPU OPT/System fan speed detection
  • CPU/System/Chipset overheating warning
  • CPU/CPU OPT/System fan fail warning
  • CPU/CPU OPT/System fan speed control
  • 2 x 128 Mbit flash
  • Use of licensed AMI UEFI BIOS
  • Support for DualBIOS™
  • Support for Q-Flash Plus
  • PnP 1.0a, DMI 2.7, WfM 2.0, SM BIOS 2.7, ACPI 5.0
Unique Features
  • Support for APP Center
    * Available applications in APP Center may differ by motherboard model. Supported functions of each application may also differ depending on motherboard specifications.
    Ambient LED
    EZ Setup
    Fast Boot
    Game Controller
    Cloud Station
    ON/OFF Charge
    Smart TimeLock
    Smart Recovery 2
    System Information Viewer
    USB Blocker
  • Support for Q-Flash
  • Support for Smart Switch
  • Support for Xpress Install
OS Support
  • Support for Windows 8.1/8/7
Form Factor
  • ATX Form Factor; 30.5cm x 24.4cm
  • 3-Year

Moving over to the high-level features, you’ll see the X99-SLI has a lot to offer the overclocking and gaming crowd. As we mentioned earlier, the motherboard offers increased XMP profile support up to 3333 MHz. All below images and descriptions courtesy GIGABYTE.

Support for DDR4 XMP up to 3333MHz

DDR4 memory modules are available at a stock frequency of 2133MHz, but memory vendors encode XMP profiles which can automatically modify the frequency and timings of the supported memory modules to work in par with your CPU. With the X99 Champion Series, GIGABYTE is offering a tested and proven platform that ensures proper compatibility with profiles up to 3333MHz.

What is XMP?

The synchronization of the memory modules with the CPU is crucial for good performance of your system. DDR4 memory modules are available at a stock frequency of 2133MHz, but as frequency tweaking requires a considerable amount of effort and knowledge, memory vendors encode XMP profiles which can automatically modify the timings of the supported memory modules to work with your CPU and to achieve increased performance.

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GIGABYTE has gone exclusively with International Rectifier (IR) to provide their all-digital power design. GIGABYTE says the IR PWM controllers and PowIRstage controllers will deliver precise power delivery to achieve maximum performance from your CPU. Server level chokes and black 10K capacitors are used to ensure reliability, efficient power delivery, and a long lifespan. The single package DirectFET MOSFET design incorporates the high and low side MOSFETs along with the MOSFET driver all in one IC. To help keep these power bits cool, GIGABYTE has redesigned their heatsinks to provide even better cooling than their previous designs.

Genuine All Digital Power Design

GIGABYTE X99 series motherboards use an all digital CPU power design from International Rectifier® which includes both 4th Generation digital PWM Controllers and industry-leading 3rd Generation PowIRstage® controllers. These 100% digital controllers offer incredible precision in delivering power to the motherboard’s most power-hungry and energy-sensitive components, allowing enthusiasts to get the absolute maximum performance from their new Intel® Core™ i7 Extreme Edition CPUs.

IR Digital PWM & IR PowIRstage® ICs

This new generation of IR® digital power controllers and PowIRstage® ICs feature Isense technology, which provide more precise current sensing accuracy. This helps evenly distribute the thermal loading between the PowerIRstage® ICs, preventing the overheating of each individual PowerIRstage®, resulting in longer lifespan and better reliability.

Server Level Chokes

GIGABYTE X99 series motherboards feature Server Level Chokes.
• Server level reliability
• High current capacity
• New design reduces heat created by power loss and provides efficient power delivery to CPU VRM area.

Long Lifespan Durable Black™ Solid Caps

GIGABYTE X99 series motherboards integrate the absolute best quality solid state capacitors that are rated to perform at maximum efficiency for extended periods, even in extreme performance configurations. This provides peace of mind for end users who want to push their system hard, yet demand absolute reliability and stability, with ultra-low ESR no matter how high the CPU loading. These exclusive capacitors also come in customized jet black, exclusively on GIGABYTE X99 series motherboards.

Single Package Design

IR® has leveraged it’s world class packaging technology developed for the DirectFET®, improving the thermal capability and layout of the PowIRstage® significantly over that of other MCM packages.

Single Package Design* VS. Multi-Chip Design

Other MOSFET layout implementations use a multi-chip, side-by-side arrangement of the high and low side MOSFETs and driver ICs, taking up significant board real estate and creating more electrical leakage.

All New Heatsink Design

GIGABYTE X99 series motherboards feature new heat sink designs that offer uncompromisingly efficient cooling on key areas of the motherboard including the PWM area and chipset (PCH). GIGABYTE X99 Series motherboards offer cooling support of the crucial PWM area so even the most aggressive and extreme configurations will be kept well within optimal thermal parameters.

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The gaming crowd will appreciate GIGABYTE’s PCI-E design that uses all 40 lanes from a compatible CPU when 3-way or 4-way graphics are in play. GIGABYTE uses an onboard external clock generator and direct connection of a x16 lane to the CPU to provide up to 320 GB/s bandwidth compared to a standard design of 256 GB/s.

3-Way / 4-Way Graphics with Premium PCIe x16 Lane Up to 320Gb/s Bandwidth

GIGABYTE X99 motherboards feature a unique PCI Express design that utilizes 100% of all 40 lanes from the CPU when in a 4-Way or 3-Way graphics configuration. Standard designs limit all 4 main PCIe lanes to x8 (64Gb/s) bandwidth, but thanks to the onboard external clock generator combined with the direct connection of one of the x16 lanes to the CPU (switchless design), GIGABYTE X99 motherboards can unlock the full bandwidth available and provide the best graphics bandwidth possible to the user.

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We talked earlier about the dual M.2 slots found on the motherboard. The two slots are intended for a M.2 SSD and a Wi-Fi/Bluetooth module. The socket 3 port will support either SATA 6 GB/s or PCI-E M.2 SSDs. SATA Express is also available even though the availability of supporting devices has been extremely slow to hit the market, which casts a cloud over the viability of the interface in general.

Dual M.2 Technology for SSD Drive and WIFI CardFast Data Transfer and Advanced WIFI Networking

GIGABYTE X99-SLI motherboard featuring Dual M.2 technology provides users PCI-Express connectivity for SSD devices and for 11AC WIFI + Bluetooth 4.0 card. Delivering up to 10 Gb/s data transfer speeds, M.2 offers considerably faster storage performance than current mSATA and even SATA Revision 3 (6Gb/s) storage devices. GIGABYTE’s stacked design optimizes the PCB real-estate usage, allowing more components to be efficiently added without compromising any space.

Next Generation SATA Express Connector

GIGABYTE X99 series motherboards feature an onboard SATA Express connector which provides performance far superior to that of current SATA technologies. SATA Express features data transfer rates of up to 10Gb/s, considerably higher than SATA Revision 3 (6Gb/s), which won’t bottleneck faster NAND flash technologies in cutting edge SSDs. SATA Express combines the benefits of PCI-Express and SATA to provide much higher bandwidth, allowing SATA Express based drives to perform at similar speeds as PCI-Express based drives.

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It’s common to see a beefed up audio solution on enthusiast-level motherboards now days, and GIGABYTE continues this trend with their AMP-UP Audio Technology. Based off the Realtek ALC1150 CODEC, the onboard solution offers an audio amplifier, shielding, EMI protection, and up to 7.1 channel operation. Below is the complete list of features the AMP-UP audio solution offers.

It’s nice to see GIGABYTE use the Intel LAN solution on the X99-SLI as it’s probably the most popular choice among enthusiast users. To enhance this, GIGABYTE offers a cFOS based bandwidth prioritization software.

Realtek ALC1150 115dB SNR HD Audio with Built-in Rear Audio Amplifier

The Realtek ALC1150 is a high-performance multi-channel High Definition Audio Codec that delivers an exceptional audio listening experience with up to 115dB SNR, ensuring users get the best possible audio quality from their PC. The ALC1150 provides ten DAC channels that simultaneously support 7.1-channel sound playback, plus 2 channels of independent stereo sound output (multiple streaming) through the front panel stereo outputs. Two stereo ADCs are integrated and can support a microphone array with Acoustic Echo Cancellation (AEC), Beam Forming (BF), and Noise Suppression (NS) technologies. The ALC1150 incorporates Realtek proprietary converter technology to achieve Front differential output 115dB Signal-to-Noise ratio (SNR) playback (DAC) quality and 104dB SNR recording (ADC) quality.

Independent Right and Left Audio Channel PCB Layers

Locating the right and left audio channels on separate PCB layers, GIGABYTE X99 series motherboards are able to eliminate channel crosstalk and maintain the best audio quality.

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Intel Gigabit LAN

Intel® Gigabit LAN networking, a popular choice with gamers that features several performance-enhancing features such as advanced interrupt handling to help reduce CPU overhead and Jumbo Frame support for extra large data packets.

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For a little extra aesthetic value, GIGABYTE added LED lighting to the audio guard path. The lighting is programmable for several different effects.

Ambient LED

GIGABYTE X99 motherboards feature LED lighting for the audio guard light path and the back panel LED, providing a cool, custom look to your rig. These lights are now programmable, so you can have them beat to the rhythm of the music you are listening to, or pulse at a soothing pace to create a great atmosphere to enhance the environment of your game, movie or music.

Ambient LED Modes:

• Still Mode – LEDs stay continuously lit.

• Beat Mode – LEDs will blink to the beat of the music played through the audio jack.

• Pulse Mode – LEDs will blink slowly.

• Off – LEDs will be tuned off.

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It’s not uncommon for motherboard manufacturers to use gold plated CPU socket pins, but GIGABYTE takes it a step further and applies gold plating to the DIMM slots and PCI-E slots as well.

Gold Plating CPU Socket

GIGABYTE X99 motherboards come equipped with gold plating for the CPU socket, 4 PCIe slots and over the 8 DIMM slots, which means that enthusiasts can enjoy better connectivity, absolute reliability and longevity for the diverse connectors overtime, without having any concerns about corroded pins and bad contacts.

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To prevent damage while mounting the motherboard inside a case, GIGABYTE makes sure no circuitry is too close to the mounting holes.

Safer Design Around Screw Mounting Holes

Don’t worry anymore about accidental damage while mounting your motherboard to you chassis. GIGABYTE X99 motherboards all feature a wider copper ground pad and onboard components free area around the PCB screw mounting holes. This exclusive design reduces the chances of damaging any surrounding onboard components during the PC assembly process. Bigger copper ground pads also provide the added benefit of lower EMI disturbance for reduced noise interference across your system.

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GIGABYTE has been using their 2X Copper PCB design for quite some time now. In theory, the feature should offer better cooling and allow the trace paths to handle higher power loads.

2x Copper PCB Design(2 oz Copper PCB)

GIGABYTE’s exclusive 2X Copper PCBs design provides sufficient power trace paths between components to handle greater than normal power loads and to remove heat from the critical CPU power delivery area. This is essential to ensure the motherboard is able to handle the increased power loading that is necessary when overclocking.

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GIGABYTE’s App Center is a full featured set of desktop tools that allow easy configuration of your system. You can check for system and software updates, overclock from the EasyTune App, and a lot more.

GIGABYTE App Center Including EasyTune and Cloud Station Utilities


The GIGABYTE APP Center gives you easy access to a wealth of GIGABYTE apps that help you get the most from your GIGABYTE motherboard. Using a simple, unified user interface, GIGABYTE APP Center allows you to easily launch all GIGABYTE apps installed on your system, check related updates online, and download the latest apps, drivers, and BIOS. Customize the APP Center’s look and behavior according to your taste in the Preferences Menu.

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Overclocking Boost Your Frame Rates – Get the most from your PC with easy to use GIGABYTE overclocking features.

GIGABYTE EasyTune™ is a simple and easy-to-use Windows-based software application that allows users to fine-tune their system settings.
• Adjust system and memory clocks and voltages in a Windows environment.
• System-related information display without the need to install additional software.

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Smart Quick Boost

Smart Quick Boost provides users with different levels of CPU frequency to choose to achieve desired system performance.

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Advanced CPU OC

Advanced CPU OC allows users to set the CPU’s base clock, frequency and voltages, and integrated graphics frequency

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Advanced DDR OC

Advanced DDR OC allows users to set the memory clock with XMP profile support.

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3D Power

3D Power allows users to change power phase, voltage, and frequency settings.

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Cloud Station Server

GIGABYTE Cloud Station™ Server is composed of several GIGABYTE’s unique apps that allow your smart phone/tablet/PC devices to communicate, share resources, and control desktop PCs via wireless connection


Home Cloud

HomeCloud allows users to share the files between your smart phone/tablet device and computer or back up the files from the device to the computer.

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HotSpot turns your computer into a virtual wireless access point and allows you to share your connection with your other wireless devices.


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GIGABYTE Remote allows users to remotely control the mouse/keyboard/Windows Media Player on your computer from your smart phone/tablet device.

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Remote OC

Remote OC allows users to remotely control their desktop PC with a powerful suite of software functions that Include overclocking and system tweaking, system monitoring plus the ability to also remotely power down/reset the PC when needed.

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Auto Green

Auto Green is an easy-to-use tool that provides users with simple options to enable system power savings via a Bluetooth-enabled smart phone/tablet device. When the device is out of the range of the computer’s Bluetooth receiver, the system will enter the specified power saving mode.

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Packaging/Accessories/First Look

The retail box does a nice job of explaining the features and benefits of the X99-SLI. On the front and sides, you’ll find GIGABYTE branding, model information, and several high-level features mentioned. The back of the box has a very detailed list of the motherboard’s features, capabilities, and specifications.

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Inside the box, the motherboard sits at the top and is wrapped in an anti-static bag. Below the motherboard are the accessories, which include the following items.

  • Installation Guidebood
  • User’s Manual
  • Driver/Utilities DVD
  • Case Badge
  • 4x SATA 6 GB/s Cables
  • Flexible CrossFire Bridge
  • Flexible SLI Bridge
  • I/O Shield

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The following pictures give you a good idea of the motherboard’s layout and color scheme. As you can see, a yellowish/gold and black theme is the name of the game here. We’ll explore the X99-SLI in greater detail next, but for now enjoy the pictures!

X99-SLI Overhead View
X99-SLI Overhead View

Overhead View #3
Overhead View #3

Overhead View #3
Overhead View #3

Overhead View #4
Overhead View #4

Side Angle View
Side Angle View

Side Angle View #2
Side Angle View #2

Side Angle View #3
Side Angle View #3

Side Angle View #4
Side Angle View #4

Back of PCB
Back of PCB


At the bottom-left edge, we find the front panel audio header, SPDIF out header, the TPM connection, a pair of 4-pin system fan headers, and the first of two USB 2.0 front panel headers. Also located here is a 4-pin Molex connector to bring additional power to the PCI-E lanes, which you’ll want to use when multiple video cards (SLI/CrossFire) are installed.

Moving over to the bottom-right edge, we see the second USB 2.0 front panel header, the CPU Mode switch, the first of two front panel USB 3.0 headers, and the case wiring headers. The CPU mode switch can be enabled to take advantage of all 2083 pins found in the CPU socket, which is said to help overclocking. Left in its default position, the standard 2011 pins will be utilized.

Bottom-Left Edge
Bottom-Left Edge

Bottom-Right Edge
Bottom-Right Edge

Along the right side of the motherboard, the lower area is where all the SATA connectivity is found. All 10 SATA ports are native to the Intel chipset, and there is also full support for SATA-Express.

Further up the right side, we land at the second front panel USB 3.0 header and the 24-pin ATX power socket.

10 SATA 6Gb/s and SATA-E Ports
Right-Lower Edge

Right-Upper Edge
Right-Upper Edge

There isn’t much to see across the top of the motherboard, but the 8-pin CPU AUX 12V power connector is located here. The location of this connector is perfect for optimal cable management.

Top-Right Edge
Top-Right Edge

Top-Left Edge
Top-Left Edge

The left side of the motherboard has all the I/O connections found at the upper area. Mouse and keyboard PS/2 ports are available as well as four each USB 2.0 and USB 3.0. The white USB 3.0 port is also used as the Q-Flash Plus port for flashing the UEFI BIOS, which can be done with just standby power and no hardware installed on the motherboard. The I/O area also features an Intel LAN jack, five audio ports that support up to 7.1 speaker configurations, and an optical out port. Just below the I/O ports is a built-in bracket for attaching the optional Wi-Fi antenna connectors.

At the bottom of the left side is where you’ll find everything dealing with the AMP-UP audio solution, which we described in the features section above. EMI shielding, PCB isolation, an audio amplifier (for headphones), and independent PCB layers for the left and right channels are the highlights here. The PCB isolation line you see in the last picture below will illuminate when the system is turned on, and the behavior of the lighting can be changed between a few different options.

I/O Area
I/O Area

AMP-UP Audio Area
AMP-UP Audio Area

PCB Isolation Line
PCB Isolation Line

The X99-SLI provides four PCI-E x16 slots and three PCI-E x1 slots. Depending on the CPU used, up to 4-way SLI/CrossFire is possible at x16/x8/x8/x8 speeds provided one of the 40-lane processors are used. The 28-lane i7 5820K will allow up to 3-way SLI at x16/x8/x4 speeds.

Between the middle two PCI-E x16 slots, you find the two M.2 ports. One of them is a socket 3 connector for use with PCI-E SSDs, and the other is a socket 1 connector for use with Wi-Fi/Bluetooth modules.

PCI-E Slots
PCI-E Slots

M.2 Ports
M.2 Ports

The CPU socket area is relatively uncluttered and should allow the installation of just about any air cooling solution out there. Just pay attention to memory height if you have designs on installing one of those behemoth air coolers on the market. Water cooling CPU blocks won’t be an issue here either, we’d be hard pressed to come up with one that won’t fit.

Also viewable from the below pictures are the eight DIMM slots, which support up to 64 GB of DDR4 memory at XMP supported speeds up to 3333 MHz.

CPU Socket Area
CPU Socket Area

CPU Socket Area
CPU Socket Area

The onboard passive cooling solution consists of two heatsinks joined by a heatpipe. One heatsink covers the Intel PCH, and the other covers the MOSFETs. The MOSFET heatsink uses a thermal pad for heat transfer material, and the PCH heatsink uses a more conventional gray colored TIM. Both heatsinks were found to be well attached and making excellent contact with their target points.

PCH Heatsin Removed
PCH Heatsink Exposed

MOSFET Heatsink Exposed
MOSFET Heatsink Exposed

Heatsink/Heatpipe Assembly

Heatsink/Heatpipe Contact Side

With the heatsinks removed, we get a close look at the all-digital power delivery area. There are a total of 10 power phases on the X99-SLI – Six for the CPU and four dedicated to the memory. Each bank of four memory slots gets its own two power phases and an IR3570A VRM. The six CPU power phases use an IR3580 VRM. The MOSFETs are IR’s DirectFET design, which combines the high side MOSFET, low side MOSFET, and driver IC all in a single package design. This design saves valuable motherboard real estate and is said to reduce electrical leakage.

Six CPU Power Phases
Six CPU Power Phases


Right Side Memory Power Phases and VRM
Right Side Memory Power Phases and VRM

Left Side Memory Power Phases and VRM
Left Side Memory Power Phases and VRM

Because all the SATA and USB ports are native to the Intel X99 chipset, there isn’t much in the way of third party controllers to show you. The Realtek ALC1150 CODEC sits beneath the EMI shield that covers it (pictured earlier), but we did get a look at the Intel I218V LAN controller. Given a choice between the various onboard LAN options on the market, we think it’s safe to say most enthusiast users would opt for the Intel solution. So, it’s nice to see GIGABYTE use it on the X99-SLI.

Two ITE IT8792E controllers are used for fan control and monitoring. The ITE IT8620E provides temperature and voltage monitoring, along with other vital system information. The ITE IT8951E is used to provide the built-in Q-Flash Plus UEFI BIOS flashing feature. Lastly, several NXP L04083B ICs provide the PCI-E switching capabilities.

Intel I218V Lan Controller
Intel I218V Lan Controller




NXP L04083B


GIGABYTE provides three ways in which to explore the UEFI BIOS. For quick, down and dirty setup options, a trip to the Startup Guide is all you need. There is a limited amount of options available here, but for the novice user looking for basic settings to get them going… perfect.

UEFI BIOS Startup Guide
UEFI BIOS Startup Guide

For the complete set of UEFI BIOS options, the user can choose between Smart Tweak Mode and Classic Mode. Smart Tweak Mode offers the same amount of settings as Classic Mode, but it’s presented in a more colorful and stylistic layout. Here are a few screenshots of the Smart Tweak Mode, so you can get a feel for the look and layout.

Smart Tweak Mode
Smart Tweak Mode
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Classic Mode still seems to be holding on as the favorite UEFI BIOS for the majority of old school GIGABYTE users. Old habits are hard to break! Classic Mode offers everything you need for system customization, including overclocking, fan control, system monitoring, and even a firmware flashing utility.

When you first enter Classic Mode, you land at the M.I.T. area where all the overclocking, voltage, memory, fan control, and monitoring options are found. There are plenty of options here for even the most seasoned enthusiast, overclocker, and gamer.

Classic Mode - M.I.T. Section
Classic Mode – M.I.T. Section
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The System Information section is just that and provides basic information on the BIOS version, memory, etc. The date and time can also be set from here.

System Information Section
System Information Section

The BIOS Features section has all the system post behavior options. The boot priority settings are located here, as well as several other options that are probably best left at their default settings for the majority of users.

BIOS Features Section
BIOS Features Section

The Peripherals section is where you can set the behavior of the audio LED lighting and configure a few different USB and LAN settings.

Peripherals Section
Peripherals Section

Peripherals Section
Peripherals Section

The Chipset section contains all the SATA port configuration options and the options to enable/disable onboard devices.

Chipset Section
Chipset Section
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The Power Management section contains common items found on most modern motherboards. The ability to use your keyboard or mouse to power the system on is a nice feature found here.

Power Management Section
Power Management Section

Rounding out the UEFI BIOS tour is a quick look at the Save & Exit section. Pretty standard stuff here too, but you do have the ability to save up to eight profiles directly to the UEFI BIOS. An unlimited amount of profiles can be saved to an external storage device.

Save & Exit Section
Save & Exit Section

BIOS Profile Saving
BIOS Profile Saving

Benchmarks and Overclocking

Test System

Here are the components used in our test bed.

Test System Components
MotherboardGIGABYTE X99-SLI
CPUIntel i7 5960X Haswell-E
MemoryG.SKill Ripjaws 4 DDR4-3000 MHz 4X4 GB kit
SSDSamsung 840 Pro 256 GB SSD
Power SupplyCorsair HX1050 Professional Series
Video CardEVGA GTX 780 Ti Classified
CoolingEKWB Supremacy EVO Water Block – 360 mm Radiator – MCP35X Pump
OSWindows 7 Professional x64

We’ll use our standard set of benchmarks to test compression, rendering, video conversion, and memory performance. We’ll run a few 2D benchmarks as well. We don’t typically see any noteworthy differences when comparing motherboards, especially given we keep the same CPU, chipset, memory, and GPU standardized. So, as we normally do, we’ll just provide screenshots of the stock and overclocked benchmark results. This is basically a way for us to search out any abnormalities the motherboard may exhibit during the benchmark runs. We’ll go back and spot check these results against other X99 motherboards we’ve reviewed to make sure everything is up to snuff.

With just a raise in CPU voltage to 1.375 V and a few modifications to the power delivery, overclocking the CPU to 4.75 GHz was a painless affair. The XMP profile on our DDR4-3000 MHz kit defaults the BCLK to 125, which means we used a CPU multiplier of 38 to achieve the overclock. So, we’ll use 4.75 GHz for the overclocked results you see below. When we get to the Pushing the Limits section of the review, we’ll see how much is left in the tank for a suicide run or two. The stock benchmarks were run at the CPU’s turbo speed of 3.5 GHz locked down, which is typically how we like to do the stock testing.

Compression, Rendering, and Video Conversion Benchmarks

Cinebench R10 – R11.5 – R15

CB R10 @ 3.5 GHz CPU / 3000 MHz Memory
CB R10 @ 3.5 GHz CPU / 3000 MHz Memory

CB R10 @ 4.75 GHz COU / 3000 MHz Memory
CB R10 @ 4.75 GHz CPU / 3000 MHz Memory

CB R11.5 @ 3.5 GHz CPU / 3000 MHz Memory
CB R11.5 @ 3.5 GHz CPU / 3000 MHz Memory

CB R11.5 @ 4.75 GHz COU / 3000 MHz Memory
CB R11.5 @ 4.75 GHz CPU / 3000 MHz Memory

CB R15 @ 3.5 GHz CPU / 3000 MHz Memory
CB R15 @ 3.5 GHz CPU / 3000 MHz Memory

CB R15 @ 4.75 GHz COU / 3000 MHz Memory
CB R15 @ 4.75 GHz CPU / 3000 MHz Memory

x264 Pass 1 and 2

x264 @ 3.5 GHz CPU / 3000 MHz Memory
x264 @ 3.5 GHz CPU / 3000 MHz Memory

x264 @ 4.75 GHz CPU / 3000 MHz Memory
x264 @ 4.75 GHz CPU / 3000 MHz Memory

PoV Ray R3.73

PoV Ray @ 3.5 GHz CPU / 3000 MHz Memory
PoV Ray @ 3.5 GHz CPU / 3000 MHz Memory

PoV Ray @ 4.75 GHz CPU / 3000 MHz Memory
PoV Ray @ 4.75 GHz CPU / 3000 MHz Memory

7zip Compression Benchmark

7zip @ 3.5 GHz CPU / 3000 MHz Memory
7zip @ 3.5 GHz CPU / 3000 MHz Memory

7zip @ 4.75 GHz CPU / 3000 MHz Memory
7zip @ 4.75 GHz CPU / 3000 MHz Memory

2D Benchmarks

Wprime 32M and 1024M

wPrime @ 3.5 GHz CPU / 3000 MHz Memory
wPrime @ 3.5 GHz CPU / 3000 MHz Memory

wPrime @ 4.75 GHz CPU / 3000 MHz Memory
wPrime @ 4.75 GHz CPU / 3000 MHz Memory

SuperPi 1M and 32M

SuperPi 1M @ 3.5 GHz CPU / 3000 MHz Memory
SuperPi 1M @ 3.5 GHz CPU / 3000 MHz Memory

SuperPi 1M @ 4.75 GHz CPU / 3000 MHz Memory
SuperPi 1M @ 4.75 GHz CPU / 3000 MHz Memory

SuperPi 32M @ 3.5 GHz CPU / 3000 MHz Memory
SuperPi 32M @ 3.5 GHz CPU / 3000 MHz Memory

SuperPi 32M @ 4.75 GHz CPU / 3000 MHz Memory
SuperPi 32M @ 4.75 GHz CPU / 3000 MHz Memory

Intel XTU

Intel XTU @ 3.5 GHz CPU / 3000 MHz Memory
Intel XTU @ 3.5 GHz CPU / 3000 MHz Memory

Intel XTU @ 4.75 GHz CPU / 3000 MHz Memory
Intel XTU @ 4.75 GHz CPU / 3000 MHz Memory

Memory Benchmarks

Aida64 Cache & Memory

AIDA64 @ 3.5 GHz CPU / 3000 MHz Memory
AIDA64 @ 3.5 GHz CPU / 3000 MHz Memory

AIDA64 @ 4.75 GHz CPU / 3000 MHz Memory
AIDA64 @ 4.75 GHz CPU / 3000 MHz Memory


MaxxMEM @ 3.5 GHz CPU / 3000 MHz Memory
MaxxMEM @ 3.5 GHz CPU / 3000 MHz Memory

MaxxMEM @ 4.75 GHz CPU / 3000 MHz Memory
MaxxMEM @ 4.75 GHz CPU / 3000 MHz Memory

After spending quite a bit of time comparing the above results to previously reviewed X99 motherboards, the GIGABYTE X99-SLI performed right on par with all of them. As expected, it was a tad better in some benchmarks and a tad behind in others, but we’re talking minute differences either way. Excellent showing for the X99-SLI here.

Pushing the Limits

Our usual sucide runs of SuperPi 1M and wPrime 32M were able to complete at just a little under 5.0 GHz… 4.98 GHz to be exact. The memory was left at 3000 MHz too, which is pretty impressive at that CPU speed. We wouldn’t call these settings completely stable by any means, but it does demonstrate the overclocking ability of the X99-SLI. Good stuff for sure!

SuperPI 1M @ 4.98 GHz CPU / 3000 MHz Memory
SuperPI 1M @ 4.98 GHz CPU / 3000 MHz Memory

wPrime 32M @ 4.98 GHz CPU / 3000 MHz Memory
wPrime 32M @ 4.98 GHz CPU / 3000 MHz Memory


The performance and overclocking ability of the GIGABYTE X99-SLI speaks for itself as we witnessed above. GIGABYTE proved you don’t have to spend four or five hundred dollars for an X99 motherboard that’s capable of building an enthusiast-level system around. In fact, the X99-SLI can be had for $250 at Newegg, which lands it at the mid to lower end of the X99 motherboard spectrum.

With support for up to 4-way SLI/CrossFire, the AMP-Up audio, the Intel I218V LAN controller, and M.2 device compatibility, the GIGABYTE X99-SLI provides the latest technologies and an overall attractive feature set. That should make the motherboard appeal to a large segment of potential customers, especially given the affordable price.

If you’re looking for an X99 motherboard that’s affordable and doesn’t sacrifice overclocking or gaming opportunities, the GIGABYTE X99-SLI is definitely worth consideration.


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Dino DeCesari (Lvcoyote)

About Dino DeCesari 230 Articles
Dino DeCesari was a pillar of the community for over 13 years when he passed away suddenly in 2015. His legacy lives on through his hundreds of computer hardware reviews posted here. Dino spent time in the army as a Telecommunication Center Specialist and received a commendation medal. He had a successful 20+ year career in the automotive parts and technology industry, where he eventually bought and sold his own business. Once retired, he volunteered as tech support for a non-profit and his local school district. 

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53 messages 1 likes

This board has the extra pins in the socket for uncore/cache frequency overclocking, right?

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annnnnnd it's gone

4,816 messages 0 likes

For once a board that looks nice and neutral, 4way sli and good price.

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