The GeForce 7950 GX2 Uncovered

I guess up to now you gotten a good idea on how the NVIDIA GeForce 7950 GX2 looks like and what it is capable off. But what can we find beneath all that which is covered by the heatsink? Well that is exactly what you will get to see now. We removed the heatsink of the GeForce 7950 GX2 to see which main components we could find. Of course this could only be done after having unfolded the GeForce 7950 GX2 card.

Once the screws where loose we could easily remove the heatsink and the full scale PCB saw the light. The PCB is quite different from what we have seen so far on any GeForce 7 series based graphics card. Most of the electronic components have been visible, but not the main once who make the difference. The heatsink is different from what we have seen in the paste as well. It is a well design heatsink which will also cool the memory chips. The spot that will make contact with the GPU features a copper square. This will certainly increase the cooling ability and performance of the G71 core.

The GeForce 7950 GX2 is powered by the G71 series line of graphics processors, with each PCB equipped with one G71 core. The G71 core used is physically the same chip as you will find back on the GeForce 7900 GTX video cards and features 24 pipelines. The NVIDIA G71 chip uses a 90nm manufacturing process for its high performance circuits and is actually an optimized die shrink from the previous G70 chip. The GeForce 7900 GX2 core works at 500MHz operation speed, actually a lot lower clocked then the GTX which is set at 650MHz.

Next to the G71 chip we will find in total eight memory chips and one extra bridge chip. This BR3 bridge switch comes only on one PCB which will act as the main PCB and that will control the PCI Express interface. The second PCB doesn't have a PCI Express interface but will communicate with the first PCB. To allow a smooth utilization and to let both board work together the BR3 chip has been developed by NVIDIA and is essential to the performance delivered by the GeForce 7950 GX2 card.

There is a new chip on the card that NVIDIA developed that acts as a physical PCI Express bus splitter, namely the BR3 bridge switch. It takes the single physical 16-lane PCI Express slot that is fed to the card and splits it into two full 16-lane PCI Express connections; one to each GPU. This logic is then responsible for the merging of the data back into a single 16-lane connection when it goes back across the PCI Express bus. As already mentioned NVIDIA has somehow crippled the GeForce 7950 GX2 by only using 8 lanes to each GPU, which might impact the performance.

And lastly some details on the memory chips used on the GeForce 7950 GX2 which will give a total of 1GB per card, meaning 512MB frame buffer per GPU. NVIDIA has opted for the high performance Samsung memory chips which are rated at 1.4ns, so ending up at 1.4GHz. Once again these are down clocked to only 1.2GHz which leaves some room for improvement, so some potential overclocking. These chips should easily go up to 1.5GHz and even higher.