
Table of Contents
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 | |
CPU |
|
Chipset |
|
Memory |
|
Audio |
|
LAN |
|
Expansion Slots |
|
Multi-GPU |
|
Storage | Chipset:
Chipset:
|
USB | Chipset:
Chipset + Renesas®uPD720210 USB 3.0 Hub:
|
Internal I/O |
|
Back Panel Connectors |
|
I/O Controller |
|
H/W Monitoring |
|
BIOS |
|
Unique Features |
|
OS Support |
|
Form Factor |
|
Warranty |
|
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.
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.
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.
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.
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.
|
![]() | ![]() |
|
![]() | ![]() |
For a little extra aesthetic value, GIGABYTE added LED lighting to the audio guard path. The lighting is programmable for several different effects.
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.
To prevent damage while mounting the motherboard inside a case, GIGABYTE makes sure no circuitry is too close to the mounting holes.
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.
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.
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.
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.
|
|
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!
The GIGABYTE X99-SLI Up Close
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.
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.
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.
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.
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.
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.
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.
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.
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.
The GIGABYTE UEFI BIOS
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.

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.
![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
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.
![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
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.

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.

The Peripherals section is where you can set the behavior of the audio LED lighting and configure a few different USB and LAN settings.
The Chipset section contains all the SATA port configuration options and the options to enable/disable onboard devices.
![]() | ![]() | ![]() |
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.

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.
Benchmarks and Overclocking
Test System
Here are the components used in our test bed.
Test System Components | |
Motherboard | GIGABYTE X99-SLI |
CPU | Intel i7 5960X Haswell-E |
Memory | G.SKill Ripjaws 4 DDR4-3000 MHz 4X4 GB kit |
SSD | Samsung 840 Pro 256 GB SSD |
Power Supply | Corsair HX1050 Professional Series |
Video Card | EVGA GTX 780 Ti Classified |
Cooling | EKWB Supremacy EVO Water Block – 360 mm Radiator – MCP35X Pump |
OS | Windows 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
x264 Pass 1 and 2
PoV Ray R3.73
7zip Compression Benchmark
2D Benchmarks
Wprime 32M and 1024M
SuperPi 1M and 32M
Intel XTU
Memory Benchmarks
Aida64 Cache & Memory
MaxxMEM
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!
Conclusion
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.
Click the stamp for an explanation of what this means.
2 replies
Loading new replies...
Registered
annnnnnd it's gone
Join the full discussion at the Overclockers Forums →