Two GPUs are great, but are three that much better? When it comes to multi-card scaling, can AMD finally beat Nvidia? Who really needs this much performance? We loaded a super-fast system in single-, dual-, and triple-GPU configurations to find out.
OCZ-Z1000M: 1000 W Modular, ATX12V v2.2, EPS12V, 80 PLUS Gold
Software
OS
Microsoft Windows 7 Ultimate 64-bit
GeForce Graphics
GeForce/Ion 266.58
Radeon Graphics
AMD Catalyst 11.1
Chipset
Intel INF 9.2.0.1019
CPU “bottlenecks” are always a problem at medium (and lower) resolutions. Today’s tests start at medium resolutions, so we clocked Intel’s Core i7-2600K to 4.0 GHz in an effort to minimize that issue.
The Achilles-heel of Intel’s fastest processor is a platform that supports only sixteen PCIe 2.0 lanes directly from the processor to the graphics card. Asus solves that solution by incorporating Nvidia’s 32-lane NF200 bridge, thereby repeating the same information at full bandwidth to two cards simultaneously. Triple-GPU mode operates in an x8/x8/x16 configuration, as it would with most X58 motherboards.
Power might be the price for performance, but we wanted to see if it also scaled with performance as GPU numbers increased. OCZ’s 80 PLUS Gold-rated Z1000M provides that clean power while adding only around 11% overhead at our watt meter.
Alien vs Predator Benchmark Tool Test Set 1: Highest Settings, No AA Test Set 2: Highest Settings, 4x AA
Crysis
Patch 1.2.1, DirectX 10, 64-bit executable, benchmark tool Test Set 1: Highest Quality, No AA Test Set 2: Highest Quality, 4x AA
F1 2010
v1.01, Run with -benchmark example_benchmark.xml Test Set 1: Highest Settings, No AA Test Set 2: Highest Settings, 4x AA
Just Cause 2
Version 1.0.0.2, Built-In Benchmark "Concrete Jungle" Test Set 1: Highest Details, No AA, 16x AF Test Set 2: Highest Details, 4x AA, 16x AF
S.T.A.L.K.E.R.: Call Of Pripyat
Call Of Pripyat Benchmark version, all options, HDAO Test Set 1: Ultra Preset, DX11 EFDL, Ultra SSAO, No AA Test Set 2: Ultra Preset, DX11 EFDL, Ultra SSAO, 4x MSAA
Synthetic Benchmarks and Settings
3DMark 11
Version: 1.0.1.0, Benchmark Only
Stay On the Cutting Edge: Get the Tom's Hardware Newsletter
Get Tom's Hardware's best news and in-depth reviews, straight to your inbox.
scrumworksImpressive and unexpected results. Speculations that crossfire scaling is worse than SLI can finally be put into rest.Not true, I would have liked to see more games on the test. The choices were too limited for my taste. For example, everyone knows that Crysis is heavily Nvidia favored, so it's not surprising to see those results in the least.
Here's another article on the 68xx series in Xfire
http://www.xbitlabs.com/articles/video/display/radeon-hd6870-hd6850-crossfirex.html#sect0
Xfire scaling was found to be 100% on 10 or the 19 games they tested, and remaining very high on the others. Nvidia and ATi seems to trade blows at different games tested, but it is evident that Ati has stepped up their Xfire drivers int he 6xxx series.
scrumworksImpressive and unexpected results. Speculations that crossfire scaling is worse than SLI can finally be put into rest.I misunderstood what you meant. But yes, xfire/sli scaling has improved alot this generation :)
Its really cool to see amd stepping up their game. Multigpu scaling used to be only good on nvidia, but now amd is beating them. Though i feel that more games should be tested before a firm conclusion should be drawn.
No! Don't buy a 5000-series card to crossfire. The 6000 series cards are essentially all better at crossfire scaling than their predecessors. This performance advantage will likely only increase with additional driver revisions and better 6000-series optimization support than for older products.
