you would have to solder the extra missing bank, I did that on my XFX 8800GS but it will only unlock 112, the other shaders are bad

thats the problem, its a game of chance

Nvidia was really smart when they wrote the reference bios's, its its costless vs disabling the cores physically which requires very expensive equiptment, the G92's have 32sp's and 4 rops per memory cluster, therefore by removing 1 cluster nvidia got 96 sps and 12 rops on the GS, the only exception is the 8800GT's who's cores do not have 128SP, only 112 as the G92-270-A2's with 28sp's per cluster were the very first G92 cores, the G92-400-A2's were the 128sp core versions but during production the lower binned cores were pushed to another line where they were labeled the G92-150-A2, some are just as good as their 8800GTS512/9800GTX brethen but some aren't.

for example on my GS I could get it up to near stock 8800GTS 512mb performance before I modded it which was amazing for a 50 dollar card