ASUS C90 Overclocking Laptop

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A close look – Joe

SUMMARY: Part I – A look at this laptop’s specs.


Pic courtesy of Directron

The good guys at Directron were nice enough to help get a loaner of the ASUS C90 Overclocking Laptop (ASUS site here) to me so we could take a close look at what is one of the few true overlcocking-capable laptops available. One of the main attractions I see (in addition to the OC) is that it makes servicing and updating the laptop over time much easier than the not-user-friendly offerings from other manufacturers.

First we’ll take a look inside and then cruise the specs that define what this laptop can do.

The back comes off easily by removing five screws:


A closer view shows the area surrounding the CPU socket:


This shows the fan bay – there is a CPU cooler that will fit in the right hand side:


The back view shows the four cooling fans – these are Delta each rated @ 9500 rpm, 13 cfm, 36.5 dBA. At full tilt, these four fans must make a racket; however, there is software in BIOS that controls fan speeds based on temps, so they should be moderated in use.


Feature List

Asus’s website lists part of the features that this laptop should support as shown below:

Key Features:

Processor & Cache Memory

LGA775, Supports Intel ® Core ™ 2 Extreme processor up to X6800, 4MB L2 Cache, 2.93GHz, 1066 MHz FSB

Support Operating System

Windows Vista ® capable


Main Memory

2 SO-DIMM Sockets for Expansion Up to 3GB
Support up to 3GB Dual Channel DDRII 533/667MHz SDRAM

Video Graphics & Memory

NVIDIA Mobile PCI Express Module up to GeForce 8600M GT 256MB/512MB


Up to WSXGA+(1680×1050) Color Shine 15.4” LCD

Hard Drive

Supports 2.5″ 9.5mm SATA HDD
160GB: supports 7200RPM


fan-control & multi-heat pipe thermal module; Four Delta AFB0412VHB fans, each rated @ 9500 rpm, 13 cfm, 36.5 dBA

Optical Drive

5.25″ 12.7 mm 8X / 24x24x10x(max.), support DVD Combo, DVD Super-Multi, HD DVD and Blu-ray Drive

Video Camera

2.0 Mega pixels rotate CMOS Camera with Face tracking function

Card Reader

8-in-1 MMC/SD/Mini-SD/XD/MS/MS-Pro/MS-Duo/MS-Pro-Duo


Built-in 10/100/1000 Mbps LAN
Integrated V.92 MDC Fax/Modem w/ Azalia Ver 2.1 compliant 802.11 a/b/g/n
Optional built-in Bluetooth ® V2.0+EDR


1* e-SATA Connector
1* D-Sub VGA Port
1* Headphone-out Jack(SPDIF)
1* Microphone-in Jack
1* RJ11 Modem Jack
1* RJ45 LAN Jack
3* USB 2.0 Ports
1* TV-Out (S-video/Composite Video)
1* IEEE 1394
1*MCX connector for TV-RF
1*Express Card 34 / 54 Support


Built-in Azalia Compliant Audio Chip
Built-in high quality speakers and 2 internal microphones


19 mm full size with MS-Windows function keys
2.5mm travel
Vista K/B Start Button

Hot Keys

Power, Turbo Gear, Internet, Email, Touchpad Lock

AC Adapter

Output : 19V DC, 4.73A, 90W
Input : 100~240V AC, 50/60Hz Universal

Battery Pack & Life

Li-Ion 6 cells: 4800mAh, 53W (removable): Smart Battery, 2.5hrs Quick charge 95% (Power Off) / 4hrs (Power On)

Dimension & Weight

14.4 x 10.5 x 1.3~1.7 inch
6.8lbs (with Battery)

Supplied Accessories

Built-in Bluetooth V2.0+EDR
Finger Print Recognition
TV Tuner (optional)
Carrying bag

Table courtesy of ASUS

The above table tells part of the story – for more details, I went to Intels site and found the following specs from Intel ® 82945G Features document:

Processor Interface

  • Intel ® Core 2 Duo, Intel ® Pentium ® 4 processor in the 90 nm process in the LGA775 Land Grid Array package or Intel ® Pentium ® D processor (supports 775-Land package)
  • Supports Pentium 4 processor FSB interrupt delivery
  • 533/800/1066 MT/s (133/200/266 MHz) FSB
  • Supports Hyper-Threading Technology1 (HT Technology)

Note that this laptop supports only Core 2 Duo – it would have been better if the other CPUs were supported, especially if you have some CPUs you’d like to recycle.

System Memory

  • 4 GB maximum memory
  • One or two 64-bit wide DDR2 SDRAM data channels
  • DDR2 400, DDR2 533, DDR2 667
  • Bandwidth up to 10.7 GB/s (DDR2 667) in dual-channel Interleaved mode.
  • Non-ECC memory only
  • 256-Mb, 512-Mb and 1-Gb DDR2 technologies
  • DDR2-667 4-4-4 is not supported
  • The speed used in all channels is the speed of the slowest DIMM in the system

No real suprise here except that you have a wide range of choices.

Graphics Features

PCI Express Graphics Interface

  • One x16 PCI Express port
  • Compatible with the PCI Express Base Specification, Revision 1.0a
  • Raw bit rate on data pins of 2.5 Gb/s resulting in a real bandwidth per pair of 250 MB/s

This supports the PCI graphics slot.

Integrated Graphics Device

  • Core frequency of 400 MHz
  • 1.6 GP/s pixel rate
  • 3D Graphics Rendering Enhancements
  • VLD/iDCT for enabling dual Intel ® High Definition streams for MPEG playback

Note also that the chipset supports both analog and digital video output.

Analog Display Support

  • 400 MHz Integrated 24-bit RAMDAC
  • Up to 2048 x 1536 @ 75 Hz refresh
  • Hardware Color Cursor Support
  • DDC2B Compliant Interface

Digital Display Support

  • Two SDVO ports multiplexed with PCI Express graphics interface
  • Can combine two channels to form one larger interface
  • Flat panels up to 2048 x 1536 @ 60 Hz or digital CRT/HDTV at 1920 x 1080 @ 85Hz
  • Dual independent display options with digital display
  • Supports TMDS transmitters or TV-Out encoders


So far so good – the physical layout is easy to get to and work on and the feature list is impressive. Once I get the CPU to take it for a test drive I’ll report back on how much overclocking this laptop allows.

The Barebones Experience

If you’ve built your own PC, rounding up the pieces for a laptop and assembling it will not be a big deal. However, be forewarned:


What you get is a bunch of little plastic bags with tiny screws in them and two heatsinks – one for the CPU and one for the GPU. The Manual that ships with the laptop explains how to turn it on and what the buttons do – that’s it. You have to figure out where these tiny screws go and how to shoehorn the heatsinks into place. The mechanically-challenged should avoid the barebones experience.

In my case, the ASUS C90S needed the following components:

  • Desktop CPU
  • Videocard
  • Memory
  • Hard Drive
  • WiFi Card
  • OS

The good guys at Directron supplied the CPU (an E6320) and videocard – the ASUS nVidia GeForce 8600M GT 512MB (there is a 256 MB version available HERE.) It has a plate on the top onto which the GPU heatsink mounts – you figure this out by looking at the parts you have and then have an “Now-I-see” epiphany. The epiphany was what to do with three tiny spring-mounted screws – “Now I see – they’re for the GPU heatsink!”

A word on the CPU; ASUS will tell you that the E6320 is not supported – according to ASUS:

“The C90S supports Core 2 Duo (Conroe) “E4300, E6300, E6400, E6600, E6700, X6800″. Core 2 Duo (Merom) NO, Core Duo (Yonah) NO, Pentium M (Dothan) NO, Celeron M NO. E6320 is a newer Conroe and unfortunately is not supported by the C90S.”

I relate this because I found this out after I asked Directron for the E6320, as the spec sheet was not as specific on what CPUs are supported as my subsequent inquiry. As I found out, the E6320 will work fine as will the E2160. This is the fun part of the barebones experience – finding out what works and what doesn’t (as an aside, I also found out that it runs without the battery installed).

For the RAM I decided to buy some cheapo PNY – I wanted to see if this would work and it did – no problem. The only other part was the hard drive and that’s a no-brainer standard part. I did not use a WiFi card as I have sworn off wireless routers, so I can’t add anything on that.

I had some questions and I called ASUS laptop tech support – it’s available 24/7 and it’s really true – I called on a Sunday night and got a live tech located in California. This was almost a jaw-dropping experience – no wait. However, you must accept that the more esoteric your question, the less likely you will get an answer. Let’s face it – the techs can handle the routine stuff easily – anything that’s outside the script is a crap shoot.

Even so, I was pleasantly surprised with ASUS tech support for laptops – nice guys trying their best to be helpful.

Overclocking the ASUS C90S

ASUS is marketing the C90S as an “overclocking laptop”, so that’s what I concentrated on trying out. I installed the OS (XP), booted into Windows and then installed all the drivers that ship with the C90S. The screen on the C90S is stunning – native resolution is 1680 x 1050; for some of the veterens among us, you may have to adjust text size – for me it was a bit too fine but setting text size larger fixed it.

The C90S is “certified” for Core 2 Duo E4300, 6300, 6400, 6600, 6700 and 6800. Naturally the first CPU I tried was an E6320 to see what else worked:


Booted up and ran fine – no problems. I would have thought this to be the case as it seems the only significant difference is the cache size – 4 MB vs 2 MB for the others. The Intel 945G Express Chipset supports FSBs of 533, 800 and 1066. On the off chance that somehow a pad-modded CPU to 1333 would work, I tried but no joy. As the chipset supports Pentium D, I tried that also but no joy on that one.

Next I decided to throw in an E2160 that I pad-modded to 1066 – this is the CPU that came with the Dell Vostro 200 that I reviewed HERE. I figured since the chipset supports 1066, this should work OK – and it did:


It ran reasonably cool at that speed as well:


Next I tried to overclock the E2160 using the ASUS overclocking utility – no matter what I did, I had no luck getting it to work. Based on some posts I have seen, this is not unusual. What did work was the power saver mode which dimmed the screen and slowed down the CPU. This is of limited use as you can get the same thing using a program like NHC.

I ran benchmarks to show how the ASUS stacked up against some other systems:


These benches are similar to PCs using an E6600 running at 2.4 GHz – no real surprise.

Overclocking Results

Software overclocking has a mixed record – sometimes it works great, sometimes it’s a bust, sometimes it works but blue-screens under stress. As the basis for calling the ASUS C90S an “overclocking laptop”, I’d have to say it’s a stretch. I would not buy it based on the overclocking software utility that comes with it. I had expected to see more flexibility in BIOS, but sadly that’s not the case – you can’t vary FSBs or memory timings in this BIOS.

However, as a laptop that will easily accommodate pad-modded CPUs, the ASUS C90S is very easy to tweak. While the BIOS is a total bust as far as overclocking settings, the ease of getting into this laptop’s system board far outweighs any other shortcomings. I can’t stress this enough – anyone who had tried to clean a dust-clogged laptop cooler usually finds that getting to the CPU cooler involves MAJOR disassembly.

The other encouraging factor I found was that most likely all E series CPUs from the 2000 to 6000 series will work no problem in this laptop. I can’t tell you that anything above 3 GHz will work, but it looks like the best bet is pad-modded 800 MHz FSB CPUs running at 1066 MHz at CPU frequencies below 3 GHz. As the E2000 and E4000 series are good buys on eBay, these can make a very nice, low cost alternative to something like an X6800.

CPU/GPU Cooling

One of the distressing features of many laptops is how warm/hot they run under normal use. Pushing the envelope by overclocking is going to result in a fair amount of heat generation, as the C90 uses desktop CPUs. This laptop features a complex of four fans – three directly tied to the CPU’s temperature and one dedicated to the GPU.

The overarching problem facing all laptop designers is the miniscule footprint for a heatsink. The picture below compares Intel’s retail heatsink for an E6300 to the ASUS heatsink:


While the ASUS looks like a cut above the norm, it still does not compare in fin area to Intel’s desktop heatsink. Compared to a “tower” heatsink, it’s downright anemic. It should come as no surprise that the heat coming out of this laptop’s back could warm a small room. At a minimum, a good laptop cooler with a gasket (HERE) can go a long way to more effective cooling.

The GPU cooler sits on top of the videocard:


In use, I found under “normal” use that the fans were not at all noisy – even when they kicked on, they ran at low speed so that noise ws minimal. Frankly this surprised me as the fans are 12 volt Deltas that, at full bore, will be quite nosiy. One thing I would have liked to see in BIOS was a way to set at what temps the fans start to kick in – this is pre-set and not alterable in BIOS.

I ran some tests with a digital thermometer placing a thermocouple at the C90’s exhaust port with the following results:

Test with E6320 @ 1.87 GHz

CPU Die Temp

Ambient Temp

Exhaust Temp

P95 Stress Test








At first glance it may seem strange to see higher exhaust temps at idle, but at idle the fans are very low to off – almost passive cooling. Under stress the fans spin up, hence the lower exhaust temps reflecting cooling airflow through the fins.

ASUS C90S Built-in Camera

The C90 features a built-in camera – rated at 2 MegaPixel, here’s an example using the “snapshot” mode (640 x 480):


Not bad for what it is – nice coverage and an OK detail level.


Almost two years ago I reviewed the ASUS Z71A, another ASUS laptop that was very easy to overclock and to work on. I tried a number of mods on this one, including watercooling, and still use this every day as my main PC. Overall it’s been a workhorse and has never been a problem for me.

The ASUS C90S looks like a worthy successor – it has a dynamite screen, is easy to work on and will accept a variety of pad-modded CPUs. The cooling complex with four fans is unusual but does the job – under normal use, the fans were not noisy; pushed, they will be, as they should.

The C90S is marketed as a DTR – I would not haul this around as a portable, but that’s me (almost 7 pounds in my book is not a portable). As a DTR, I don’t doubt that the more enterprising among us could easily mod the C90S for watercooling. As I demonstrated with the Z71A, it’s very doable as long as portability can be sacrificed; after all, it is a DTR.

I give high marks to ASUS for 24/7 notebook tech support – I used it and got a real person on a Sunday evening!

Many many thanks to ASUS and Directron for their patience and support for this review.

Summary: Laptop Barebones is not complicated, but knowing what goes where helps.

The ASUS sells the C90S as a barebones laptop, which is a great move for those of us who like to roll our own. However, the Manual available from ASUS is NOT a “How-To” manual. As an example of what’s involved in setting up a bare-bones laptop, I wrote the following How-To as an example.

Opening the Back

I think one of the positives for a barebones laptop is the ability to perform routine maintenance, such as cleaning dust from the heatsinks – trying this on some laptops involves a level of disassembly that turns into a daunting task. The back of the C90S:


The back plate comes off after removing only four screws – they are identified with the following symbol:

Back Screw Detail

The four screws are located as shown in red:

Back Screws

Remove the screws, then SLIDE the back cover off by pushing it from the front towards the back – then you see this:


Remove the battery when working on a laptop – you don’t want live circuits.

Videocard Install

The C90S needs a videocard, so installing one is a necessary step. When the laptop is shipped without a videocard installed, the VGA area looks like this:

VGA Slot

The heatsink you see here is for the northbridge chip. The videocard installs easily into the slot – as with RAM, it goes in at an angle:

Videocard Install

Next take two small screws and while holding the videocard down against the screw posts, tighten the screws:


The two screws to hold the videocard in place are circled in red – the arrows point to the mounting holes for the VGA heatsink – it’s the smaller one included in the parts that ship with the C90S. The VGA heatsink’s base matches to top plate of the VGA card:

VGA Heatsink

Line it up and similar to the CPU heatsink, wiggle it into place – it’s in place when the three holes in the heatsink mate to the three holes in the videocard’s top plate:

VGA Screw Holes

You’ll find three spring-loaded screws in the parts packages – these are for the VGA heatsink.

VGA Screws

Snug them down and that’s it! The CPU and VGA heatsinks are the most difficult tasks – installing the hard drive and RAM will complete the build.

VGA HS Installed


CPU Install

Installing the CPU is absolutely straight forward – the C90S uses desktop CPUs, so the socket is a standard desktop socket. Line up the CPU to the socket’s index pins, and close the socket.

CPU Socket Open

Add some thermal grease and then slide the heatsink’s fins into place. You have to keep the heatsink almost touching the CPU as you slide it into place – you may have to wiggle it into place. Once in place, then tighten the heatsink in place with four small screws:

CPU HS Installed

If you remove the heatsink, the thermal grease acts like a suction cup – you have to move it around and lift the heatsink to break its grip.

Installing RAM

RAM is the easiest – there are two RAM slots. RAM is installed at an angle; once securely in the socket, push down and it will clip in place:

RAM Install

After all these steps, the C90S will look like this (ex the hard drive):


Note the location of the two heatsinks – the fins fit snuggly into the fan bracket assembly; be patient, you may have to play with it to get it in place. Whatever you do, don’t force anything!

Hard Drive Install

Piece of cake – there is a hard drive bracket which will attache to the hard drive:

HD Cage

Without the bracket the drive will not be secure:


Screw the bracket to the drive and slip into its connector:


Last step is to secure the drive in place with two small screws, located as shown in red.

Other Cards to Install

I did not install the WIFI card on this laptop, but its located at the upper right hand side of the motherboard.


Finishing off a barebones laptop is not difficult, but it would be nice to have a Manual to guide you through what goes where and how. The benefits for me far outweigh the discovery process you may have to go through. I gave ASUS high marks for marketing barebones laptops, even lacking an assembly manual.

Email Joe


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