Originally Posted by Undervolter
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...
Yup, people overclock and run Prime95 for like 20 minutes and are "stable" Then they get a few blue screens of death and some data corruption that comes with them. Then that corruption cascades and their Windows install is borked. Then you have the guys that spend days tweaking voltages, timings etc... Run Prime95 making sure no workers drop out, more tweaking.... They get fast overclocks and stable machines.