|
nVidia GeForce 6600 GT AGP Review |
|
Written by Phyro
|
|
Tuesday, 16 November 2004 |
Beyond3D has send word about their review on the nVidia GeForce 6600GT AGP videocard. nVidia's midrange follow-up to the GeForce 6800 was released in September, under the guise of the GeForce 6600, with the 6600 GT filling the top spot of that line of products. With the NV43 chip that powers the 6600's being built as native PCI Express this left AGP users, who are in the vast majority at the present time, nowhere to turn if they were attracted to these boards.
 nVidia GeForce 6600 GT AGP Review
However, nVidia had previously released the "HSI" bridge chip, such that they could convert their AGP based graphics chips to operate on the PCI Express interface – theoretically this HSI bridge could just be reversed in order to enable a PCI Express graphics chip to operate in and AGP interface.
A little over a month later nVidia are now ready to unveil the AGP version of 6600 GT. The necessary inclusion of the HSI bridge has resulted in an interesting board design, however while the performance specifications of the PCI Express and AGP versions are close, the full speeds don't quite make it across to the AGP version. Here we'll take a closer look at the GeForce 6600 GT for AGP.
In all, the AGP GeForce 6600 GT throws up few surprises in relation to the PCI Express version in terms of gaming performance, once we factor in the decrease in memory bandwidth. The overall gaming performances come in at around 8% below the PCI Express version in graphics limited cases, but given the generally high performance of the 6600 GT's this isn't too much of an issue. The only times this difference increases is under high resolution FSAA situations, where some textures are pushed over to system RAM and so the performance of the graphics interface becomes more critical – given that this only occurs at high resolution with high FSAA levels its questionable whether the performances would be viable in these situations anyway.
The decision to clock down the memory on the AGP version, in relation to the PCI Express 6600 GT board, is a little curious, although there may be a few potential explanations. What we may think as being an obvious one, cost, isn't quite as obvious as it seems – the inclusion of an extra chip, the HSI bridge, will increase board costs so something may be cut back to offset that cost, however in the case of the memory the same 2ns modules are being used on both AGP and PCIe versions, so the physical memory costs will be the same for both models. Potentially there may be validation costs savings at the board level, or possibly the layout of the board makes high speed routing a little trickier. Another potential reason may be that this is being used as an incentive for people to upgrade from AGP to PCI Express systems by only offering the highest performance on the PCI Express boards – it wouldn't surprise us to see this occurring more frequently as the push to PCI Express becomes more prominent.
The inclusion of the GeForce FX 5800 Ultra in this article also highlights exactly the importance of a flexible shader pipeline in current gaming titles. The top level fill-rates and geometry performances between the 5800 Ultra and the newer 6600 GT's are fairly similar, and yet in gaming titles, even DirectX8 ones that rely heavily on multi-texturing and not so much on shaders, the 6600 GT's show large performance gains over nVidia's two year old high end technology. The performance delta's are widened with more recent DirectX9 titles that make frequent use of shaders within the applications, and the under the Counter Strike Source Video Stress Test the 6600 GT, running DirectX9 shaders is even able to outperform the 5800 Ultra running DirectX8!
The GeForce 6600 GT now gives AGP system owners a good high performance, but cost sensitive choice.
|
ASUS 9800GTX+ (DK) PCIe 512MB - Rev 01
