Page 2 - Technology & Specifications
The Technical BlahblahThe GT card tested today will be offered in 128 and likely 256 MB configurations. I expect you to go for the 256 MB version as that's the trend, however we received the 128 MB model. The GeForce 6600 series product line has 8 Pixel pipelines and 3 Vertex processors that are confirmed to be working 100% with Rivatuner:
$0100000000 Graphics core : NV43 revision A2 (8x1,3vp)
The 6600 series can write four color pixels per clock and has a fragment crossbar. The NV43 does appear to have eight pixel shader/texture units, so its not an "8 x 1" design or a "4 x 1" design. It's more of a hybrid and works quite well.
When we look at clock rates something very interesting is happening here. Where the PCI-Express models are have the memory clocked at (2x)500 MHz, the AGP version has been down-clocked a little and is running at (2x)450 MHz, or 900 MHz effectively, for its memory:$0100000005 Core clock : 500.000MHz
$0100000006 Memory clock : 450.000MHz (900.000MHz effective)
I can already tell you that the performance between AGP and PCI-Express is about the same. One can only speculate about the frequency difference. One possibility is that cheaper memory was need to offset the added cost of the HSI bridge chip (more on that later) that was needed for the AGP version. Whatever the reason, this could mean some very nice potential for overclocking performance, as this product is a little memory bandwidth limited.
Let's have a look at the cards configuration and compare it to NVIDIA's GeForce Series 6 product line:
$ffffffffff Display adapter information
$ffffffffff ---------------------------------------------------
$0000000000 Description : NVIDIA GeForce 6600 GT
$0000000001 Vendor ID : 10de (NVIDIA)
$0000000002 Device ID : 00f1
$0000000003 Location : bus 1, device 0, function 0
$0000000004 Bus type : AGP revision 3.0
$0000000005 AGP status : enabled
$0000000006 AGP rate : 4x 8x supported, 8x selected
$0000000007 AGP SBA : hardwired, enabled
$0000000008 AGP FW : supported, enabled
$ffffffffff NVIDIA specific display adapter information
$ffffffffff ---------------------------------------------------
$0100000000 Graphics core : NV43 revision A2 (8x1,3vp)
$0100000001 Hardwired ID : 014a (ROM strapped to 0140)
$0100000002 Memory bus : 128-bit
$0100000003 Memory type : DDR (RAM configuration 07)
$0100000004 Memory amount : 131072KB
Among the next pages you'll see a photoshoot of this product. It'll show you a bit more clearly how NVIDIA accomplished making the NV43 (Series 6600), which is a PCI-Express GPU, compatible with AGP 8x. Actually it's quite simple. You all know that NVIDIA was able to make AGP products PCI-Express compatible compatible (ex: the PCX5300 and PCX5900) thanks to the High-Speed-Interconnect solution (HSI bridge chip). Back in March in the CeBIT article I briefly talked about the HSI's functions and possibilities with NVIDIA. NVIDIA confirmed that the HSI will work the other way around too and that is precisely the solution they are using.
In the most laymen explanation, you just flip around that HSI-chip and it can be used to make a PCI-Express product compatible with AGP 8x, it works backwards. And it works really well, I might add. In the photoshoot I'll demonstrate clearly where the HSI is located on the card, it actually is a very funny design to see. For now, have a look at both the AGP and PCI Express reference models:
On top, the AGP model, below PCI-Express. You can see they really had to cram in that cooler and make space for the HSI chip.
Specs GeForce 6600 GeForce 6600 GT GeForce 6800 GeForce 6800 GT GeForce 6800 Ultra Codename NV43 NV43 NV40 NV40GT NV40U Transistors ? ? 222 million Process, GPU maker 110nm 110nm 130nm, IBM Core clock 300 MHz 500 MHz Up to 400 MHz 350MHz 400-450 MHz Memory 128MB DDR1 128MB GDDR3 128MB DDR1 256MB GDDR3 256MB GDDR3 Memory bus 64/128-bit 256-bit Memory clock Up to manufacturer 2x500 MHz
2x450 MHz (AGP)2 x 550MHz 2 x 500MHz 2 x 600MHz PCB P212 P212 P2?? P210 P210 Pipelines 8 8 12 16 16 FP operations FP16, FP32 DirectX DirectX 9.0c Pixel shaders PS 3.0 Vertex shaders VS 3.0 OpenGL 1.5+ (2.0) Price $150 $229 $299 $399 $499 Availability Oct 2004 Oct/Nov 2004 May/June 2004
As you can unmistakably see there is a product for
any budget. It is obvious that NVIDIA is pretty happy with the Series 6 graphics processor, they announced Series 6 in April and look what is saturating the retail and OEM market already. Pretty marvelous.