XFX 8800GTS Alpha Dog Overclocking AdventureVoltage Modifications & Extra Works
The G92 chipset has been running the 3DMark threadmill for hours on end. It's cold under the Noctua, and hungry too. We can feed it some juice by doing some voltage modifications to the 8800GTS. It took us a while to figure the works and eventually realised that some of the guides have already been scattered over the Net. The modification points for most purposes are identical to the 8800GT, so we won't take any credit for it.
Map to Clockers' Cove.
Measure points.
We figured that we could just dump you a picture and leave you in the lurch, but here's a few points to take note as we explain the modifications. The top-left dot is the feedback sense pin of the PX3544. The less voltage it detects, the more it causes the regulation system to pump out. The feedback pin on the ISL6459 is pin 4, shown in this diagram as the bottom-right dot. You need to find linear (B type) multiturn variable resistors for better control over voltages. Bourns, Nidec (Copal) and Spectrol makes them, amongst others. They are stocked by major retailers electronic supplies mail order chains like RS, Farnell, Allied, Digikey, Arrow and Tandy. Singaporeans can pop over to this thread for some shopping tips. To castrate the overcurrent protection, get rid of the three resistors marked with "78X" on them. This optional modification may however allow extra stresses on the VRM system.
Default Vgpu is around 1.17V, while default Vmem lies at about 2.02V. We gave the core a nice 1.22V and tested a few different memory voltages before settling at 2.07V. This gave us 837/2106/1098 in clocks. 3DMark06 registered 17199. Looking at Deep Freeze framerates, that's roughly 22% faster than any run-of-the-mill 8800GTS.




Comments (10)



