Asus GeForce 8800 GT – first look

Posted at: 12:54pm 29th October 2007 by Clive Webster

Almost as fast as the GeForce 8800 GTX, but for much less money

With Christmas approaching, manufacturers are frantically churning out their merchandise. Shiny new products range from silly, stocking-filler fripperies to huge items that won’t even fit under the tree. The new GeForce 8800 GT graphics card slots in between these two extremes - it’s a long graphics card (9in, in fact) with a single-slot cooler on top. It’s the card that Nvidia hopes you’ll buy this Christmas, but why?

This is the first PCI-E 2.0 card we’ve seen, so obviously, it’s almost twice as good as those rubbish old PCI-E 1.1 cards, right? As ever, though, matters aren’t that straightforward. All PCI-E 2.0 offers over PCI-E 1.1 is twice the usual bandwidth (if the chipset supports PCI-E 2.0, which currently only applies to the super-expensive Intel X38) and some extra power through the slot. Determining whether the extra bandwidth makes a difference to gaming performance is nearly impossible, as you can’t switch between PCI-E 1.1 and PCI-E 2.0 on an X38 motherboard. This means that we’d have to test on different motherboards, which would invalidate any comparative results. At least PCI-E 2.0 is backwards compatible with PCI-E 1.1, so this card will work in any motherboard with a 16x PCI-E slot.

First, we tested to ascertain whether an X38 board could power the card through just the slot, thus avoiding the need for a separate PCI-E power cable. Unfortunately, though, the card wailed like a distressed pre-pubescent on helium until we plugged in the 6-pin PCI-E connector. With a PCI-E 2.0 slot providing 150W of power (double that of a PCI-E 1.1 slot), the GeForce 8800 GT resides in the high-energy bracket of GPUs. However, our test system only drew 240W from the socket during gaming, making the GeForce 8800 GT 6W less energy-hungry than a 320MB GeForce 8800 GTS.

Nvidia has stated that the board will draw no more than 105W, and also claims that the chip will be more power efficient compared to its predecessors when idle. This frugality of power consumption is good considering the specs of the new GPU, codenamed G92. There are 112 stream processors running at 1.5GHz, while the rest of the GPU runs at a respectable 600MHz. That means that the core of the 8800 GT runs faster than that of the 8800 GTX (575MHz), while the stream processors are clocked at the same speeds as those on the 8800 Ultra.

A little maths shows just how impressive this new GPU is. Take the amount of stream processors and multiply it by the speed at which they operate, and you have the number of peak stream processor operations per second. As it’s the stream processors that are rendering the eye candy, this figure is fairly indicative of performance even if it's only a very rough guide. The 112 stream processors in the 8800 GT run at 1.5GHz, so this GPU has a peak of 168 billion stream processor operations per second. Comparatively, the 8800 GTS (either version) has only 96 stream processors running at 1.2GHz, providing ‘only’ 115.2 billion stream processor operations per second.