There's been a lot of focus lately on how ATi and nVIDIA's mainstream cards only have half the rendering pipelines of their high end counterparts. Let's remember something here though, both the NV43 and R410 have eight pixel rendering pipelines. This is the same number as on the Radeon 9800XT, and twice that of the GeForceFX 5950 Ultra, and those cards are still pretty darn fast. That should already tell you that performance will be good.

As mentioned earlier, the GeForce 6600GT core is built on IBM's 0.11 micron manufacturing process and contains a whopping 146 million transistors. nVIDIA has cut the vertex pipelines from the six found in the GeForce 6800 class cards to three in the GeForce 6600GT. To economize further, the memory controller has also been cut in half to 128bit. That means at high resolutions with AA/AF enabled, the NV43 will not be able to handle things as well as its more expensive sibling.

There are two models of the NV43, the GeForce 6600GT and plain GeForce 6600. The 'GT' that we're testing now has a core clock speed of 500 MHz, and memory running at 1 GHz. The vanilla Geforce 6600 version runs at 300 MHz core / 500 MHz memory. Both cards support all the latest DirectX 9.0C goodness as well as nVIDIA's SM (Shader Model) 3.0.

Twin Videocards with nVidia SLI

One of the most exciting features of the Gigabyte GV-NX66T128D is support for nVidia's SLI (Scalable Link Interface, not Scan Line Interface as 3dfx called it) technology. What this means is with a compatible motherboard, you can run two PCI Express GeForce 6600GT videocards in parallel! In theory this will potentially double the raw rendering power of the system!

SLI today is different than it was back in 1998 when 3dfx released the Voodoo2. Back then, two Voodoo2 cards would each work on half the image to be rendered. The primary card would render all even lines of the resolution while the secondary card would render the odd lines.

nVIDIA does things a bit differently. One card renders the top half of the image and the other card renders the bottom half. These cards are linked together with a U-shaped connector that comes with the motherboard.

At the moment you can only SLI videocards of the same class, for example two GeForce 6600GT's or two GeForce 6800 Ultra's, but not a 6600GT and a 6800 class card. Whether or not you'll be able to SLI lower end cards with higher end cards in the future is still unclear (but we wouldn't bet on it).

Overclocking!

Overclocking is always a lot of fun, but finding the absolute top speed on nVIDIA videocards has been more difficult ever since nVIDIA integrated thermal throttling into their cores. They meant well, of course... after all nVIDIA is just trying to save its customers from damaging their videocards.

Keeping this in mind, I began to raise the clock speed of the core slowly. We got to 570 MHz with no graphics issues at all. Feeling brave, I made a big jump to 600 MHz. Sadly, the card instantly locked up. By playing nice again, we reached a top speed of 583 MHz. Anything more and the card would lock up while running the CodeCreatures benchmark.

Since this card uses Samsung K4J55323QF-GC20 GDDR3 BGA DRAM modules, I had some high hopes for overclocking the memory. Going up in 10 MHz intervals, we were easily able to pass the 1.1 GHz mark. Artifacts only started to appear once we passed 1.13 GHz. Definitely not a bad overclock from 2ns memory!

Things took a turn for the worse once we tried to get the core and memory to overclock together. At 583 MHz core and 1.13 GHz memory we saw heavy artifacting when running 3D benchmarks. In the end we had to lower the core speed to 568 MHz and the memory to 1.07 GHz. Anything higher on either setting and the card would give us problems.

PCStats Test System Specs:

system 1 system 2 processor: intel pentium 4 540 intel pentium 4 3.0c clock speed: 16 x 200 mhz = 3.2 ghz 15 x 200 mhz = 3.0 ghz motherboards: gigabyte 8anxp-d, i925x gigabyte 8knxp, i875p videocard: gigabyte gv-rx60x128v gigabyte gv-nx57128d msi pcx5750-td128 albatron trinity pc5900 asus extreme eax600xt gigabyte gv-rx70p256v gigabyte gv-nx66t128d ati radeon 9800xt ati radeon 9800 pro ati radeon 9700 pro asus radeon 9600xt msi fx5950 ultra-td128 msi fx5900u-vtd256 msi fx5900xt-vtd128 aopen geforcefx 5900xt memory: 2x 256mb crucial ballistix ddr2 2x 256mb corsair twinx 3200ll hard drive: 40gb wd special ed 40gb wd special ed cdrom: gigabyte dvd burner msi x48 cd-rw/dvd-rom powersupply: vantec stealth 470w vantec stealth 470w software setup windowsxp build 2600 intel inf 6.0.1012 catalyst 4.11 detonator 66.93 windowsxp build 2600 intel inf 6.0.1012 catalyst 4.11 detonator 66.93 benchmarks 3dmark2001se 3dmark05 codecreatures aquamark gun metal 2 x2 the threat ut2003 doom3 aa test, af and aa+af test 3dmark2001se x2 the threat ut2003

the agp and pci-e systems are different, but the results are included for reference. we usually run aquamark3 tests, but unfortunately the benchmark refused to run with the gigabyte gv-rx70p256v.