Originally Posted by an65001
It takes 1.41v on my FX-8320 to get 4.2 stable, and even then my RAM ruins the stability. I really need a better kit of RAM.
Yes, i never overclock, but i have noticed some crazy values from people who just want to celebrate their uber chip and they think that Prime is more or less useless... i 've seen crazy undervolting claims too...Especially in Thubans, i remember once a guy claiming so low voltages that it seemed almost a 65W chip. Of course he never provided a 10h run of Prime, so i don't believe he had a golden chip.
Originally Posted by UltimatePlatano
Some people don't even boot at 1.2v I was reading that its not necessary to run prim that long because no one runs a PC 12 str8.. What's the benefits of tuning prim so long?
Up to a few years ago, the "Bible" of overclocking was requiring to pass 24hours straight Prime95, before claiming a stable overclock. In the most recent years, this has gone down to 30 minutes, in a race between users that only cared to post CPU-Z "validations" with higher clocks.
There is even a new "fashion" amongst FX users, that when their overclock can't pass Prime95, they blame the software and not their overclock. Oddly enough, other FX users manage to pass Prime95, so it can't be software problem.
The "benefit", is simply because the algorithms that are ran during Prime95, are not the same. If you look carefully, you will notice that they are different. And CPUs that aren't perfectly stable, will sooner or later fail in a different algorithm. I 've had undervolting attempts failing after 6 hours Prime. I 've had times where it would pass IBT but not Prime after 10 hours. Even more, i 've had times where it would pass Blend for 8 hours,but not largeFFT for less hours.
At the end, there are many users that are happy enough with "almost stable". But, to my experience, if you stress the CPU a lot, sooner or later, an instability in Prime, will show. A BSOD that happens once a month, a mysterious corruption of your windows installation, it can be anything. Then people go to fora and complain about software problems, that in reality were caused by their "non perfectly stable" overclock. Same applies with undervolting really...
The lowest booting voltage, oddly enough, is also motherboard dependent. The FX-6300 is stable at 1.185v on my Asrock 970 board, while needs 1.23v on my Gigabyte 970 board (at stock frequency).
But 1.23v for 4.2Ghz, sounds a bit too optimistic for me... It could happen in a very good chip, but unless you run Prime for 10h at least, you can't be really sure. As i said "old school" overclockers, before the trend of showing off CPU validations was out, used to run 24h Prime. I stop at 12h plus IBT, because undervolting is less complicated and haven't witnessed any instability doing so, despite putting full load on CPU for days non-stop.