Uncovered, Under the Hood

Indeed at MVKTech we are taking a look under the hood by pulling of the cooling solution. As you know by removing the cooling system you are voiding the warranty. For those who don't care about the warranty and want to see what's under the hood, with proper handling the heatsink can be removed for what ever reasons. We don't recommend it however. We are starting by removing the packplate and by this uncovering the EVGA e-GeForce 7800 GS CO SuperClock.

Once the backplate has been removed, the heatsink can be taken of and the full scale PCB sees the light. I must admit I was a bit surprised to find such a bare PCB underneath the heatsink. Most electronic components have been visible from the start on the frontside of the PCB. EVGA devised a new cooling solution for their e-GeForce 7800 GS CO SuperClock edition board; hence the CO in the cards came.

The CO in this case stands for copper. EVGA uses copper on their e-GeForce 7800 GS CO edition board rather than aluminum because copper is a better conductor of heat. The only downsides to copper are that it's pricier and heavier than aluminum. EVGA places the copper heatsink inlet directly over the GeForce 7800 GS's G70 core. This separated inlet is responsible for cooling just the graphics core.

At the backside of the GeForce 7800 GS we removed the backplate. It is now that we see why the bigger backplate comes in handy. The backplate is first of all used to secure the heatsink and secondly to cool the four memory modules that we find back on the backside of the PCB. Since the GeForce 7800 GS board uses high performance memory chips the extra cooling is more then welcome, and certainly an added value performance wise.

A closer look at the frontside of the GeForce 7800 GS shows the main components, namely the G70 core and HSI bridge. Since the G70 cores are native PCI Express chips the HSI bridge is needed to translate the PCI Express signals towards the AGP interface. This can clearly be seen by the electronic paths routed from the GPU to the HSI (BR2) bridge towards the AGP interface. The bridge is actively cooled by the card's heatsink, just like the G70 CPU.

The EVGA e-GeForce 7800 GS CO SuperClock is powered by the G70 series line of graphics processors. The A2 revision of the G70 on the e-GeForce 7800 GS is physically the same chip as that on a GTX or GT PCI Express. The NVIDIA G70 chip uses a 110nm manufacturing process for its high performance circuits, although NVIDIA has just recently moved to a lower 90mm process which will eradicate limitations with both frequencies and higher heat dissipations.

On top of that NVIDIA had to equip the GeForce 7800 GS AGP board with a HSI bridge to convert the native PCI Express chip functions into an AGP compatible interface. This is nothing new for NVIDIA as this HSI bridge chip has already been extensively used on the GeForce 6 series to convert from PCI Express to AGP and vice versa. It just adds some extra complexity to the manufacturing of the GeForce 78000 GS AGP video cards.