Ever since the release of nVidia's 8800 series way back in November, the graphics industry has been in a kind of suspended animation. Those willing to spend more than Â£200 on a graphics card were well catered for but the rest of us were left to wonder whether it was worth buying a DX9 card now or whether it was best to wait until midrange DX10 hardware started to appear.
Well, at last we no longer have to make that decision as nVidia has stepped up to the plate and announced three new DirectX10 products, the GeForce 8600 GTS, GeForce 8600 GT and GeForce 8500 GT. Priced from $229 all the way down to $89, these cards now mean that everyone has at least one DX10 capable option, whatever their budget. All we need now is for ATI to provide us with some competition!
While all three cards were announced last week, nVidia has said that the 8500 GT and 8600 GT won't be available immediately and the 8600 GTS was the only card to truly 'hard launch' last week. So, today we're just taking a look at a pair of these cards. Rest assured though, the other two cards should be appearing before the end of the month and we will be reviewing them as soon as we get our hands on some.
For this launch we were very graciously provided with full retail cards from MSI and Leadtek so later on we shall compare them against each other and check them against other cards available to see how they stack up. First, though, I'll go into a little more detail about just what lies beneath those heatsinks.
Unlike the 8800 GTS, these new cards are not cut-down versions of the G80 (8800 GTX) core and are based on brand new designs named G84 and G86. The former powers the 8600 GTS and 8600 GT, while the latter lies under the hood of the 8500 GT. As well as the obvious reduction in sheer performance, these new cores feature a brand new video processing engine dubbed Video Processor 2 - Iâ€™ll talk more about this later.
There are 289 million transistors squeezed into the G84 core, which is about half that of the G80s 691 million. No, great surprises there. However, itâ€™s interesting to note it actually has more than nVidiaâ€™s previous generation high-end offering - the G71 - that had a measly 278 million. Progress, hey!
Within that silicon youâ€™ll find 32 stream processors which, if you recall, are nVidias answer to the unified shader architecture of DirectX 10. Rather than having separate hardware for vertex shading and pixel shading, these stream processors can perform whatever function is desired of them. This results in a much more efficient use of the graphics hardware, reducing potential bottlenecks, and theoretically boosting performance. We saw in our reviews of the 8800 GTX and 8800 GTS that this logic held up as they were two very fast cards. However, they respectively featured 128 and 96 stream processors, which would account for a lot of their performance prowess. Whether a mere 32 stream processors will be able to keep up with the more traditional solutions, used by the likes of the 7600 GT and X1650 XT, remains to be seen.
As with the G80, each cluster of 16 stream processors is accompanied by a texture processor. However, each processor has now been bolstered so that it can now address eight textures and perform 16 filtering operations per clock. This should help to keep things as efficient as possible.
As well as the reduction in stream processors, the G84 has seen its allocation of ROPs drop from 24 to eight resulting in a memory interface that is just 128-bits wide. This means these cards are likely to struggle with high levels of anti-aliasing when coupled with high resolutions.
G86 is essentially identical to G84 except one of the clusters of 16 stream processors has been removed, resulting in a total of 16 stream processors. This is quite a dramatic drop compared to the other cards in the 8x00 range but it must be remembered that we're talking about a product that will cost $89. Both ROP partitions remain from the G84 so you still get eight ROPs and a 128-bit memory interface.