Specifications and Test System
|GeForce 7900 GTX||GeForce 7950 GX2|
|Transistor count||278 million||278 million x 2|
|Manufacturing process||0.09 micrometer||0.09 micrometer|
|Die Area||196 mm²||196 mm² x 2|
|Core clock speed||650 MHz||500 MHz|
|Number of pixel shader processors||24||24 x 2|
|ROPs||16||16 x 2|
|Number of vertex pipelines||8||8 x 2|
|Peak pixel fill rate (theoretical)||10.4 Gigapixel/s||16 Gigapixel/s|
|Peak texture fill rate (theoretical)||15.6 Gigatexel/s||24 Gigatexel/s|
|Memory interface||256-bit||256-bit x 2|
|Memory clock speed||1.6GHz GDDR3||1.2GHz GDDR3|
|Available Memory||512MB||512MB x 2 = 1024MB|
|Peak memory bandwidth||51.2GB/s||76.8GB/s|
While the manufacturing process and the die have remained the same, the GeForce 7950 GX2 GPUs run at the specification using a lower voltage than single GPU configurations. The results are 143W peak power consumption for the GeForce 7950 GX2 compared to 95W for a GeForce 7900 GTX and 125W for a Radeon X1900 XTX. The minimum PSU requirement has been raised from 22A @ 12V of the GeForce 7900 GTX to 27A @ 12V for the GeForce 7950 GX2.
The clock speed has been dropped from 650MHz of the GTX model to 500MHz. The standard 7900GTs run at 450MHz, so the new GPU is placed in between the two models. As mentioned before, some manufacturers have decided to offer factory overclocked cards. The number of Pixel Shaders, ROPs and Vertex Pipelines has doubled as there are two GPUs. The pixel and texture fill rate has not quite doubled because the 7950 GX2 uses 1.2GHz DDR3 memory, while the 7900 GTX uses 1.6GHz DDR3 memory. In total the memory bandwith has gone up from 51.2GB/s to 76.8GB/s
But besides speed and performance, the GeForce 7900 GX2 brings HDCP to the high-end.
If you like to read more about the other features the NVIDIA GeForce 7950 GX2 brings to the table, just check out our article here. I will not go in-depth about the other features, as we are looking at performance comparison between the two cards.
|CPU:||AMD Athlon 64 X2 4600+|
|Motherboard:||ASUS A8N-SLI Premium|
|Memory:||4x 512MB Kingston DDR400 CL 3-4-4-7|
|Harddisk||Samsung T133 300GB 7200RPM|
|Power Supply:||Tagan 480W ATX 2.0|
|Software:||Windows XP SP2, Forceware 91.33|
Such a powerful card requires a lot of CPU power to unfold its potential. Using a single core CPU may work for some time, but more and more games take advantage of dual core processors. So let's take a look at the synthetic benchmarks.