Quad SLI on ASUS Rampage III Extreme is not possible

Recently we published our 3-way SLI article. The results on that test where quite flabbergasting, SLI scaling is really good for the NVIDIA GF100 based chips and under the right circumstances 3-way SLI can benefit greatly as well.

With that in mind we figured, heck why not rebuild a new system and go for Quad SLI, use that all new quad SLI driver and set ourselves a new 3DMark vantage record. Since we ran into all kinds of CPU bottlenecks we figured let's get the best of the best in house. The choice of components was as follows:

• Four GeForce GTX 480 cards
• Rampage III Extreme (has four physical x16 PCIe slots)
• Core i7 980X (six core processor)
• 6GB triple Channel OCZ Blade memory rated 2000 MHz CAS7
• Two 1200 Watt BFG power supplies

The idea for this article was to push everything to the maximum. To bypass CPU bottlenecks we'd overclock the processor on this very capable motherboard. Once we started building this rig, after unboxing we realized .. for quad-SLI with four graphics card we'd need a 4-way SLI bridge. ASUS does not deliver that bridge with their motherboards, which should have been our first hint.

We contacted some AIBs for that bridge to no avail, we contacted NVIDIA to no avail as they actually discouraged this article as quad SLI with four cards really was only intended for the hardcore overclocking scene versus 3DMark Vantage scores) which luckily we are after and thus pushed forward), then eVGA Europe was kind enough to send out the 4-way SLI bridge. Meanwhile eVGA USA got back with a curiosity, they sincerely doubted that 4-way SLI would even work with the ASUS R3E as it has no additional NF200 switch ICs embedded on the motherboard, according to eVGA the motherboard would need 2x NF200 to support 4-way.

So with 3500 EUR worth of components in our hands, we at the very least had to verify that story. And eVGA was right .. 4-way SLI is not supported on the Rampage III Extreme. We verified with Windows 7 64-bit and the dedicated GTX 480 Quad SLI driver (197.55) and also with 197.75.

What happens is that with four cards installed the driver will only assign two cards for SLI and this this will setup 2-way SLI des[pite having four cards installed. Four way SLI will simply not kick in with the R3E. So there goes our dream to shatter the 3DMark Vantage score for now (hey its a sport, forgive me for trying to reach the g-factor ;)

Now for a motherboard targeted at the uber enthusiast hardcore overclockers I have to say, this is a bit of a disappointment really.

eVGA will try and get a proper 4-way SLI X58 send out our way, so later on we do hope to bring you a nice quad-SLI article, but for now this project has halted.

Here are some photo's of the setup we had built for this article. Waddayathink ? Discuss here.