NVIDIA GeForce 8800 GT: The Only Card That Matters

The First PCIe 2.0 Graphics Card

NVIDIA's 8800 GT is the "world's first consumer GPU to support PCI Express 2.0." Although AMD's Radeon HD 2400/2600 have PCIe 2.0 bandwidth, they don't implement the full spec, leaving the 8800 GT technically the first full PCIe 2.0 GPU. Currently, the only motherboard chipset out that that could take advantage of this is Intel's X38. We have yet to play with benchmarks on PCIe 2.0, but we don't expect any significant impact on current games and consumer applications. Currently we aren't bandwidth limited by PCIe 1.1 with its 4GB/sec in each direction, so it's unlikely that the speed boost would really help. This sentiment is confirmed by game developers and NVIDIA, but if any of our internal tests show anything different we'll certainly put a follow-up together.

PCIe 2.0 itself offers double the speed of the original spec. This means pairing a x16 PCIe 2.0 GPU with a x16 electrical PCIe 2.0 slot on a motherboard will offer 8GB/sec of bandwidth upstream and downstream (16GB/sec total bandwidth). This actually brings us to an inflection point in the industry: the CPU now has a faster connection to the GPU than to main system memory (compared to 800MHz DDR2). When we move to 1066MHz and 1333MHz DDR3, system memory will be faster, but for now most people will still be using 800MHz memory even with PCIe 2.0. PCIe 3.0 promises to double the bandwidth again from version 2.0, which would likely put a graphics card ahead of memory in terms of potential CPU I/O speed again. This will still be limited by the read and write speed of the graphics card itself, which has traditionally left a lot to be desired. Hopefully GPU makers will catch up with this and offer faster GPU memory read speeds as well.

For now, the only key point is that the card supports PCIe 2.0, and moving forward in bandwidth before we need it is a terrific step in enabling developers by giving them the potential to make use of a feature before there is an immediate need. This is certainly a good thing, as massively parallel processing, multiGPU, physics on the graphics card and other GPU computing techniques and technologies threaten to become mainstream. While we may not see applications that push PCIe 2.0 in the near term, moving over to the new spec is an important step, and we're glad to see it happening at this pace. But there are no real tangible benefits to the consumer right now either.

The transition to PCIe 2.0 won't be anything like the move from AGP to PCIe. The cards and motherboards are backwards and forwards compatible. PCIe 1.0 and 1.1 compliant cards can be plugged into a PCIe 2.0 motherboard, and PCIe 2.0 cards can be plugged into older motherboards. This leaves us with zero impact on the consumer due to PCIe 2.0, in more ways than one.