Dual Asus GeForce 9800GX2 on Intel Skulltrail

28 Mar 2008 | 14:29 GMT

By Nebojsa Novakovic

NVIDIA'S LATEST and greatest - surely great size-wise - card is finally out: the GeForce 9800GX2 is, as we all know, a dual GPU monster basically similar to two 8800GTS512 cards squashed together onto a single dual-PCB behemoth. And, as of this week, the Quad SLI drivers finally work.

The cards are nothing special feature-wise: dual GPUs, each running at 600 MHz with full 128 processing units, and each with 512 MB GDDR3-2000 memory. The black box design surely looks cool though, especially in pairs - maybe that was Nvidian goal, after all... tempt with the "couple buys".

Here I got two Asus EN9800GX2 units - unlike their customised and sped-up 3870X2 cards, the Nvidia dual-GPU entry here is just the reference board, nothing else. Asus packs the board with Company of Heroes: Opposing Fronts game, otherwise you're looking at a reference card.

As the Striker II Extreme test is still going on, I decided to try two of these cards on the now old workhorse: Dual-CPU 4 GHz - 8 cores total - Intel D5400XS Skulltrail mobo. 4 GB of Kingston CL4 FBD-800 RAM were there to help, that much memory is needed at least when running Vista64 to ensure no bad effects of disk paging.

Talking about Vista, I installed the SLI patch as well, just in case. Nvidia's latest WHQL driver, Forceware 174.53 was used.

Since I ran Asus' 3870X2 there before, here are the comparative 3DMark06 default results between the two cards, as well as twin Nvidias in Quad SLI mode.

Asus 3870X2

Asus 9800GX2

2x Asus 9800GX2 QuadSLI

As you can see, at low 1280x1024 SXGA resolution, ATI beats Nvidia, card for card, as long as the CPU is not a problem. The SLI add-on doesn't, well add on. But that situation would change at higher resolutions. Here is 1920x1200 WUXGA, or what I call HD 1080p ++.

Asus 9800GX2

2x Asus 9800GX2 QuadSLI

Finally, on the 30-incher, 2560x1600 4 Mpixel resolution:

Asus 9800GX2

2x Asus 9800GX2 QuadSLI

As you can see, the higher the resolution, the more benefit there is. In fact, with QuadSLI setup here, there is very little performance drop as we increase the resolution. The 2560x1600 SLI score is particularly sweet: for this resolution, these are top scores on an air-cooled setup across all three categories.

Also, keep in mind that this system has no CPU, memory or I/O bottlenecks to speak of: 8 CPU cores are fed out of quad-channel memory, with each card having its own PCI-E x16 connector - v1 only, though.

Also, Nvidia's refusal to support more than two-card SLI on Skulltrail doesn't matter here - in my mind, four GPUs on two dual-GPU cards is about as extreme as it gets on a PC. A far more serious problem is feeding all this with electric juice. A 1200W power supply is an absolute minimum here, and I'm using a Thermaltake 1500W unit just in case.

On the other hand, GPU for GPU, this card barely touches over the year-old dual 8800Ultra SLI, and that's where the problem lies: Nvidia hasn't improved its GPUs much, if at all, for 18 months now - yes DAAMIT wasn't exactly a stellar performer, but, if Intel behaved the Nvidia way, we'd be all still stuck with Q6600 Core 2 as the fastest CPU around...

In summary, this initial benchmark run does churn out some nasty results, at least in an off the shelf "classic" air cooled setup - part of the reason for this "record setting" is that ATI still hasn't perfected the Quad GPU CrossFire X scaling yet. Keep in mind that DAAMIT engineers are working on it, and that the new 3870 chip stepping, coupled with GDDR4 memory and faster PCIe v2 bridge, might spoil Nvidia's domination plans, before green goblin is ready with the 55 nm shrinks of their own.

In the meantime, let's see how the cards perform in other stuff, and how does their matching mobo, the Striker II Extreme with Nforce 790i Ultra, stack up against the Skulltrail when running these expensive cards. µ

© 2007 Incisive Media Investments Ltd. 2007