I have been trying to underclock my 5800k but am having major problems. The entire idea is to underclock and undervolt the 5800k to something closer to the 5700. My current default voltage hits 1.55 in CPUz! I can manually set the voltage down in bios...but then i loose cool and quite and since this pc will spend alot of time idling, this is not something I want to do. Im currently trying to use AMD Overdrive to set voltage down in windows after it has booted, but this resets every time i restart. I have tried setting it to run as admin and this did not fix it. The Asrock software causes cool n quite to stop when its set for auto start . Does anyone have any suggestions ?
Mobo- AsRock FM2A75- Pro4-m
8 gig 2133 aries ram set to 2133 in bios.
450 w corsair PSU Windows 8 Pro
APUs, because of being the CPU and GPU tied together, will require more voltage...don't sweat it or try to undervolt it. It needs 1.55v to run efficiently...any adjustments down very far are going to result in possible instability, and if you go too far, excess heat because the APU will draw more current due to insufficient power.
If you think undervolting it will save you money on power...that's a really silly notion. The difference you might try to recoup would be less than the difference between buying a 80 PLUS Bronze PSU and a regular PSU. The cost to operate it over the course of a year is equivalent to running one additional 100W light bulb in your house for a few hours per day...it's a $20 bill at most. Undervolting can reduce heat in a CPU, but underclocking and undervolting an APU will not really gain you much of anything...
If you really want to underclock it, then do as clutchc said and change the multiplier in your BIOS to the clock setting you want, leave COOL N QUIET alone, if your PC sits at idle mostly anyway, then you'll save more money leaving COOL N QUIET on then you will disabling it and undervolting your APU a few hundredths.
Thanks guys for your suggestions. Finally figured it out. The board was putting voltage way up when the ram was over 1866. I had also updated to a beta bios without realising it. Got the latest full release, reduced voltage back to near normal, forced power saving features to stay on and everything is running much better. CPU is down from 1.55 to 1.26max, with GPU down from 1.45 to 1.27 max. Volts and freq go down much further most of the time.Seems stable even with max load on GPU and CPU at the same time.
8350 rocks, electricity is expensive in rural Australia and this comp is on every day. Plus i imagine this pc will last me for years as a HTPC. If i can save 50-100 bucks in the life time of the PC its been worth it i guess. Was originally going to spend extra and get a Seasonic OEM Platinum PSU but realised it would take years to break even. Now all i have to do is add resistors to the case fans and find a way to shut up my hard drive...
Haha, Rob it said "plus four gig mechanical Ram: 8 gig 1600......." now reads plus 4 TB of storage Ram: 8 gig 1600..." . Ihog, i was using AMD overdrive, because unlike the bios it kept the power saving features on after changing voltages. Although like i said, after updating to the proper latest bios I have managed to get ram to 2133 while getting the voltage down and keeping cool and quite on. Im not sure I like a bios automatically increasing voltage by so much just because im running ram above 1866. Surely most people savy enough to go into bios to change their ram speed would also be able to tweak a voltage setting themselves if needed. If ignored by me, I would have had a similar voltage to people hitting 5ghz overclocks!