Overclocking using alternative cooling way
Swiftech MCW60 universal waterblock, already became a classic for me, helped me with cooling all previous cards that I had and he won’t let me down now. Those of you who bought this water-block a year ago or even earlier, can find a complete set of NVIDIA 8800 mounting hardware. Beginning from 25th of June 2009 the water block comes together with a GT200 adapter instead of G80 KIT which is needed for a current card. I bought my waterblock long time ago so there was a G80 KIT inside the package. After checking the availability of all necessary stuff, first of all, I installed factory heatsink back on the card — I found this method of cooling of memory chips and power transistors to be the most effective for that moment:
Trying to fit the waterblock on the card:
It is worth to note that there is a tiny gap between the waterblock base and a convex part of the mounting holes of the stock cooler, therefore, any universal waterblock with totally flat base may be incompatible with the stock heatsink:
I mount the waterblock and install the graphic card inside PC:
A short test with a maximum load and stability check:
Excellent temperatures. Lets continue with card overclocking.
With a maximum voltage of 1.087 V (1.145 V according to multimeter) set without BIOS modification I reached 800 MHz for GPU and 950 MHz for memory:
Checking temperature level and card’s stability by running a stress-test:
Temperatures were safe despite some serious overclocking. Again, I found this results to be clearly insufficient. After a thorough investigation of questions regarding ways of changing voltage the “software” way, i came with the conclusion that voltage limits can be extended by BIOS modification. As for now, BIOS editors that support new Fermi series videocards are on the stage of close beta testing, so I can’t share a link to the editor, but I can tell you how flash the BIOS.
Those of you who are willing to flash a new BIOS, you need to download the latest version of NVFlash. The flasher works under MS-Dos, so place this tool on a bootable flashdrive.
Before flashing, be sure to make a reserve copy of the current BIOS by typing the following command:
nvflash --save original.bin
To flash a new bios just type:
nvflash -4 -5 -6 name.bin
name.bin — BIOS file name.
Using this method I could flash a card with a modified BIOS which allowed me to change voltages up to 1.212 V in NVIDIA Inspector:
MSI Afterburner beta 5 still limits maximum voltage to 1.087 V, therefore, I continued overclocking using NVIDIA Inspector.
In the end, I could overclock card’s GPU to 885 MHz and memory to 980 MHz. I needed to increase voltage to 1.162 V (1.229 V according to multimeter) for that:
Further overclocking required more voltage, however, 1.162 V for power subsystem became a bottleneck when cooled with a stock heatsink, despite additional VRM area air cooling.
For a everyday use I have chosen more “soft” settings which showed full stability in games: