Introduction

Today we take a look at the NVIDIA GeForce 7950 GX2 1024MB, which is NVIDIA's current high-end graphic card. While the GeForce 7900 GTX 512MB was released during CeBit '06, the GeForce 7950 GX2 is the successor of the GeForce 7900 GX2 1024MB which is quite long and certainly will not fit into just any PC. Nonetheless the 7950 GX2 is advertised as a single graphic card, even with its two PCBs as it only takes one PCIe x16 slot and does not necessarily need a SLI capable chipset to run.

NVIDIA and ATI have been bunny hopping each other more than ever before, with both companies refreshing their high-end cards. NVIDIA clearly had an upper hand with their SLI technology from an implementation stand point. It is much easier to use as you only need two identical cards to run in SLI. So making two PCBs and connecting it together to run on one PCIe x16 slot was not all that hard to do.

We will compare the performance of the 7900 GTX 512MB and the 7950 GX2 1024MB in various resolutions and quality settings.

The Cards

The GeForce 7950 GX2 has just about the same size as the 7900 GTX. While the cooler of the GeForce 7900 GTX is a two slot solution, the GeForce 7950 GX2 uses two copper coolers. The back of the cards shows the much smaller number of components on the 7950 GX2 compared to the 7900 GTX.


The front of the 7950 GX2 has nothing out of the ordinary. The DVI connectors are placed on the top PCB so the bottom has the space needed for the air vent. The rear of the card shows one PCIe power connector to power the card. It draws around 143W of power according to NVIDIA. That is not much more than one X1900 XTX, but the performance per Watt ratio is much better with the NVIDIA part.


The bottom of the card has one PCIe x16 port, while the top has one SLI connector, located in the middle of the card. The previous 7900 GX2 had two SLI connectors, one on each PCB, located toward the front of the card. The 7950 GX2 is interconnected in-between the cards now.

Specifications and Test System

Specifications

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.