Looking at some of the entries for my card (GTX 760), i find a couple results very suspicious. There's no way a 760 can get up to ~500 khash/s. 2x760 in SLI, maybe, but that entry doesn't have any sort of information. The most I've been able to get mine to get up to is ~300 khash/s, but it crashes after a while. Stable, about ~290-292 khash/s
I also don't see how you can underclock the GPU Memory Clock -442. As soon as I set those settings, it instantly froze and crashed (Although I don't know TOO much about OC, so I could be wrong on this part).
Well, I'm just handling the spreadsheet, not guaranteeing it's accuracy, though I have to admit some entries seem odd.
Memory speed is a confusing one, most cards today have GDDR5 memory on them which means their effective clock speed is 4 times the default.
So for example my car has 1502 Mhz memory clock, which is 6008 Mhz effective speed. So when I let's say downclock it by 2000 Mhz in OC Guru, it will end up being 1000 Mhz instead of 1502 due to the multiplier. To further confuse the matter, some OC tools are using a 2 times multiplier so for example in EVGA Precision a -502 Mhz downclock (max) results in ~1251 Mhz and some use no multiplier, just the default speed. Which is yet another reason to use GPU-Z when it comes to overclocking.
This was all new to me too and I didn't clarified things in the survey when I made the spreadsheet so the memory clock column is all over the place, so yeah.. that's on me.