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Nvidia's GeForce 8800 GTS 512 graphics card


The 8800 GT gets a big brother
— 9:57 PM on December 10, 2007

Okay boys and girls, it's time once again for the introduction of a new video card, a happy ritual performed multiple times each year during the lead-up to Christm... err, Holiday. The video card making its debut today is the GeForce 8800 GTS 512, a brand-new big brother to the GeForce 8800 GT, which is selling like a Nintendo Wii infused with the essence of Cabbage Patch Kids, or something like that.

The 8800 GTS 512 looks to supplant older versions of the GeForce 8800 GTS by offering a more attractive mix of price, performance, capabilities, and power consumption. So, you know, it's the same old boring story in the world of GPUs. The 8800 GTS 512 is interesting in that it has, more or less, no direct competition from the Radeon camp, and its most potent competitor may be its little brother, the 8800 GT. Is there any reason to spend the extra to reach up to the new GTS? Let's take a look.


Meet the new GTS, different from the old GTS
Despite the name, the GeForce 8800 GTS 512 is actually quite a different animal than previous versions of the GeForce 8800 GTS. If Nvidia were facing more competition in the high-end of the video card market, this product would probably be called the GeForce 8950 GTS or something like that. The new card is based on the same G92 graphics processor that lies under the slim cooler of the GeForce 8800 GT. The G92 traces its design lineage to the G80 GPU that powered the original 8800 GTS cards, but it's substantially revised, with a new 65nm chip fabrication process, a PCI Express 2.0 interface, more of some things, and less of others.

The most obvious outward indication that the 8800 GTS 512 is a new product, of course, is the amount of memory it carries. Nvidia has decided to key on that fact and let the "512MB" label after the name denote the newer product. Cleverly subtle, I suppose, but to a fault. The 8800 GTS 512 is a better product in some notable ways.

At its default speeds, the 8800 GTS 512 packs quite a wallop. The G92 GPU in the 8800 GTS 512 has four ROP partitions capable of outputting four pixels each, for a total of 16 pixels per clock. Each ROP partition has a 64-bit path to RAM attached, yielding a total memory pathway that's 256 bits wide. And the GTS 512 has a total of 128 stream processors clocked at 1625MHz.

So what do those numbers mean? Well, in several cases like pixel output capacity and memory bandwidth, the new GTS 512 trails the old GTS in per-clock power. However, the GTS 512 tends to make up any deficits by running at higher clock speeds. Here's how some of the key stats look once you multiply the per-clock capacity by the clock frequency.

Peak
pixel
fill rate
(Gpixels/s)
Peak bilinear
texel
filtering
rate
(Gtexels/s)
Peak bilinear
FP16 texel
filtering
rate
(Gtexels/s)
Peak
memory
bandwidth
(GB/s)
Peak
shader
arithmetic
(GFLOPS)
GeForce 8800 GT 9.6 33.6 16.8 57.6 504
GeForce 8800 GTS 10.0 12.0 12.0 64.0 346
GeForce 8800 GTS 512 10.4 41.6 20.8 62.1 624
GeForce 8800 GTX 13.8 18.4 18.4 86.4 518
GeForce 8800 Ultra 14.7 19.6 19.6 103.7 576
Radeon HD 2900 XT 11.9 11.9 11.9 105.6 475
Radeon HD 3850 10.7 10.7 10.7 53.1 429
Radeon HD 3870 12.4 12.4 12.4 72.0 496

The 8800 GTS 512 beats the original 8800 GTS in all respects but peak memory bandwidth, where the two are very close. And the GTS 512 even surpasses the GeForce 8800 GTX in texture filtering capacity and peak shader arithmetic. That bodes very well for its performance overall.

The one caveat, if there is one, is that the GTS 512 doesn't offer much more pixel fill rate or memory bandwidth than the GeForce 8800 GT. Thanks to an extra SP cluster, the GTS 512 does have more texture filtering and shader capacity than the GT, but those advantages may not always bring better performance. The G92's ratio of shader and texture processing capacity to pixel output and memory bandwidth is much different than the G80's. As a result, pixel fill rate and memory bandwidth are more likely to be the primary bottlenecks, which could make it hard for the GTS 512 to separate itself from the 8800 GT.

If that egghead math stuff doesn't float your boat, you'd probably still want to pick the 8800 GTS 512 over the original GTS in order to see the pretty pictures from HD movies. Unlike G80-based cards, the 8800 GTS 512 supports HDCP over both links of a dual-link DVI connection—necessary for HD movie playback on very high resolution displays—and it includes Nvidia's VP2 video processing unit that provides hardware assistance with H.264 decoding. We found that the VP2-equipped GeForce 8600 GTS consumes quite a bit less CPU time during H.264 video playback than the G80-based GeForce 8800 GTX.

The cards
Physically, GeForce 8800 GTS 512 cards look very similar to their predecessors.


EVGA's take on the 8800 GTS 512


A single SLI connector means two-way SLI is probably the limit

The board is 9" long, with a dual-slot cooler that reaches that full length. The GTS 512's funky cooler places the blower at an angle from the card, presumably to allow room for air intake when the card is nestled up against another one. In front are a pair of dual-link DVI ports and an HDTV-out port. Around back is a single six-pin PCIe auxiliary power connector. Nvidia rates the card's power use at 150W, so it's just able to make do with a single aux plug. Like the GTS before it, the GTS 512 has just one SLI connector per card, not two like on the GeForce 8800 GTX. That means exotic three- and four-way SLI configurations probably won't be possible.

The EVGA card pictured above is selling for $359 at Newegg with a bundled copy of Crysis. Like many GeForce cards, this one runs at higher clock speeds than Nvidia's recommended baseline. The core clock is 670MHz, the shader clock is 1674MHz, and the memory clock is stock at 970MHz.


And here's XFX's take on the 8800 GTS 512. XFX plans several versions of the 8800 GTS, including a stock-clocked model for $349 and the one pictured above, the XXX version, which has a 678MHz core, 1728MHz shaders, and 986MHz memory, for $379. Our XXX card came with a bundled copy of Lost Planet: Extreme Condition, which means EVGA wins, in my book. Crysis is a much better game. XFX seems to have upped the ante by offering a stock-clocked version of the GTS 512 packaged with Company of Heroes for $369 at Newegg, however.

Overall, these prices are just a little lower than the going rate for a GeForce 8800 GTS 640MB. As we've mentioned, the GTS 512 doesn't really have any direct competition from AMD, unless you count running a pair of Radeon HD 3850 256MB cards in CrossFire. A couple of those cards would cost about the same as an 8800 GTS 512. However, their effective memory size would be only half that of the GTS 512. We've tested this config to see how it compares. Although it's a more expensive configuration, we've also tested a pair of Radeon HD 3870 512MB cards in CrossFire.

Since the EVGA card has the more conservative clock speed of the two GTS 512 cards we had on hand, we decided to use that one in single-card testing. We then paired it up with the XFX for SLI.