Overclocking with or without Volt-Modding
I could overclock our copy of the Gainward Bliss 7600 GS 256MB Golden Sample graphics card from its default 450/500MHz to 513/816 (1632) MHz!
The GPU frequency growth is above average for a GeForce 7600 GS chip, but as for the memory… I checked out the software. Everything worked correctly and reported that the frequency of 800MHz had been conquered. I removed once again the heatsinks from the Infineon chips to see that all the chips were indeed marked as 2.0ns! To tell you the truth, I hadn’t expected that: without any modification I made the memory work at a frequency higher than that of the senior card, GeForce 7600 GT! The PCB from the senior card must have contributed to that achievement.
But the main reason for such a high frequency growth became clear when I measured the voltages: 1.15V on the GPU, which is normal, and 2.02V on the memory chips (which are rated for a voltage of 1.8V). This is a factory-made volt-mod I have seen on some other products from Palit, particularly on the Palit GeForce 7600 GS Sonic GDDR-3 (a card with the same PCB and with similar characteristics) and Palit 7300 GT Sonic GDDR-3.
This good overclocking attempt shouldn’t stop us from getting further, though.
The Gainward Bliss 7600 GS 256 MB Golden Sample with GDDR3 is an exact copy of the earlier-tested Palit 7600 GT Sonic, so it can be volt-modded in the same way. I want to remind you once again that Gainward offers a Bliss 7600 GS 256 MB Golden Sample with DDR2 memory and with a different PCB design – this version of the card can’t be volt-modded using our method.
To check out the overclockability of the card I replaced its native cooler with a liquid cooling system that consisted of a Revoltec water-block (it is a CPU water-block but I had remade it so that it could be installed on GPUs), an external 600lph Eheim pump, and an Airplex EVO 360 radiator with three low-speed Aerocool Turbine 3000 fans. The liquid cooling system worked only for the graphics card during the test. To generally improve the thermal conditions of the card, a 120mm fan was set to blow at the reverse side of its PCB.
The GPU voltage was increased to 1.85V which helped me conquer a frequency of 753MHz. The graphics card could work at higher frequencies, too, but with occasional hang-ups and freezes. The memory chips worked at 835MHz after their voltage was increased to 2.1V, but it was problematic to use it for long under such conditions. The part of the PCB with the power elements became very hot; the GDDR3 memory chips weren’t much cooler, either. I didn’t have normal memory heatsinks at hand, and the fan didn’t help much, so I removed the volt-mod and stopped at 816MHz with the 2.02V voltage as had been set originally by the manufacturer.