Let’s take a look at the gaming performance of the cards in Single mode and
in SLI mode.


The Test Bed
AMD 3800+ NewCastle
Asus A8N SLI Deluxe
2 x Gskill 256Mb Memory
XFX 6600GT PCIE in Single and SLI mode

 

Doom 3 OpenGL Performance

Doom 3, one of the most graphics intensive games out at the market is a great
tool for benchmarking graphics cards. Display settings are set at High Quality
so that the graphics cards are thoroughly tested without the CPU bottle-necking
them.

doom3nooc XFX 6600GT PCI Express SLI Review

We see here that the nVidia cards are really strong in this OpenGL game, with
a single 8-pipeline card holding its own even in the high resolution of 1600
x 1200. I’m quite surprised that a single card can hold 47fps at this high a
setting.

We see that the performance boost 2 cards give over a single card increase
as the resolutions go up. At 1024 x 768, SLI only increases performance by 15%.
At 1280 x 1024, the performance boost increase to 43%. At 1600
x 1200, the boost increases to 67%. This certainly makes a
difference in eliminating the annoying slowdowns faced in games.

As the cards go to 600/1300Mhz effortlessly with stock cooling, I decided to
repeat the benchmarks at the high clock speeds.

doom3oc XFX 6600GT PCI Express SLI Review

You can see how the increase in clock speeds bring in a free boost of performance,
a roughly 10% increase in performance is rather nice.

To simulate how the cards would perform on a stronger CPU such
as an FX55, I overclocked the 3800+ and got some very nice figures.

doom3ocall XFX 6600GT PCI Express SLI Review

An average fps of 98.6 at 1600 x 1200 is liquid smooth and very pretty at the
same time!