ThinkPad R61 NVS 140M Overclocking Question

[Kaz_VA]

Hello,

After learning that my r61's temps a very good and messing around with different operating systems I decided I wanted to overclock the GPU, not for 24/7 normal/retro gaming use but just to see what it could do.
Installed MSI afterburner and overclocked the GPU to the highest it would let me, but after going online I realized something interesting, people overclocking the GPU 12 years ago were able to overclock it up to 650mhz [T61] but the highest option I can select is 520mhz, they could even change the voltage.
For Nvidia GPU's my knowledge around overclocking is N/A for anything older than Fermi 1.0, I know Nvidia limits how much you can overclock but why were people in the past able to select higher clocks than what I'm currently able to with the same GPU?

Also I do know about Bumpgate

[unixed]

To change the voltage you either have to do a hardware mod (originally done for a T61 by forum member binh, instructions on this forum, use the search facility) or flash a modified BIOS based on those hardware mods (the vBIOS is part of the "BIOS"). Your R61 has to share a BIOS with a T61 for you to find a modified BIOS off the shelf. Actually any existing modded BIOS won't help you much since they undervolt the GPU to various degrees. Also, the manufacturer selected voltages are either the highest available or the next highest, so there is not much headroom available. More here.