VCore voltage with A8N32-SLi & Opteron 170

This is my 1st attempt at overclocking, and I have managed to safely get to 2.6GHz on air.

However, the VCore voltage is confusing me a bit.

I read the AMD specs for this cpu here, and it's 1.3-1.35V. Not sure how correct this is, though, as it's also rated at 110W and 80A, which should make the voltage required 1.375 (W = V * A).

So, on my system without overclock, and everything set to auto, my VCore is reading 1.392V according to BIOS, CPU-Z and Speedfan (same sensor, so no surprise all are reading the same really :P )

Anyway, I did some tests and managed to get up to 2.643GHz 'stable' (20min test with Prime95 on both cores) using ClockGen in windows (anything beyond that failed with voltage at auto/standard). I decided to drop it back to 2.6GHz, and plan to do a 24Hr test at this speed.

However, in order to fix these settings, I have to manually set the VCore voltage due to the way the options are available in bios. Basically, this mobo has an option FID/HID change. This controls the CPU multiplier and VCore voltage. If left on auto, and I put the HTT up to 260, then the multiplier automatically drops to 8x.

So, knowing that I have to manually fix the multiplier at 10x, I need also to set the VCore.

This is where I'm a little unsure as to what to set for the VCore. I decided to set it to 1.35 (in an attempt to stay within specification for the cpu). However, the VCore still reports 1.392V in bios.

Is this just a perculiarity of the motherboard ? Or maybe the mobo is recognising that the CPU requires a minimum of 1.39V, and therefore supplies that ?

If anyone has had similar problems and would care to share their experiences, it would be appreciated.

Thx in advance

CPU-Z results
PSU is Tagan 580W 'Easycon' (TG580-U15)
5 answers Last reply
More about vcore voltage a8n32 opteron
  1. For some reason this mobo seems to overvolt. I would set your vcore to 1.2875 and see how you do and then go up from there if you need to.
    Good luck with it it a great board once you get all the kinks worked out with it.
  2. Some mobo Vcore settings are more flexible than others. My MSI Neo2 Plat can be set for 1.285v for the 3200+ and it runs nicely. The Foxxcomm 6150 K8MA would not go below 1.344v for my Opty165. It will happily do 1.55v with some rise in temp.

    I have not swapped cpus on my boards as its too much work. Mine you the Opty is SOI technology so very clockable, i believe. Its on my Antec Aria SFF case so i am not letting CPU load temps over 46Deg C.
  3. I have the A8R32-MVP Deluxe which is getting RMA'd due to really poor CPU performance, but messing around in the bios, i have found that it does overvolt a bit from what you set in the BIOS. When i had the voltage set to 1.35v (with the CPU overvoltage set to disabled) it would read 1.39-1.42v in windows as well as in the BIOS hardware monitor. In order to get it to 1.35v actual, i needed to set it to 1.30v, which got it to 1.34-1.36v. Keep this in mind while setting your voltage.
  4. Hi Ellis,

    "When i had the voltage set to 1.35v (with the CPU overvoltage set to disabled) it would read 1.39-1.42v in windows as well as in the BIOS". I would suspect either your board or your PSU causing such a large swing in the voltage. Not good. I guess you RMAed it for this reason ?.

    My CoolMaster Real Power 450ACLY PSU is solid and does a swing of 1.344 to 1.348 (that 0.002 volts or or 0/1% variance!). I have ran my Opty at Vcore og 1.440 volts (again 0.1% swing only) for 3 days doing SANDRa95 bURN-IN , with Folding on, Itunes blasting with visualization fullon. In effect both cores maxing out 100%. No real problems there, Running 223Mhz FSB. Just mildly clocked. Now I put the Vcore back to 1.344v and it runs fine 24 X 7 everyday. My PSU gives me the confidence in voltage stability. I had the Antec TruPower 380S. But its 12V rails pulling 11.78v under load was a concern to me, although everything was functionaing very well.

    With CM Real 450 under full load, my voltages are near perfect at : 3.30, 5.00 and 12.02volts. Both SpeedFan 3.28 and MBM5 concurs and so does Sandra 95. But Sandra gave erroneous minus voltages for some reason.

    I am happy, there is no need for me to clock it further unless I load up 4GB Ram and do VMware with 3 guest Oses.....
  5. Those were the figures that i remembered at the time. I dont know if they are actually fluctuating that much. But i when i had my ASRock 939dual, all the readings were bang on using MBM so i dont think its the PSU. The reason that im RMA'ing the board is because the move from my budget ASRock 939Dual to the "Top of the Line" A8R32-MVP actually decreased performance. My CPU scores in 3dmark06 were in the mid to high 1800's constantly, now, with this supposedely stellar board, they dropped a whopping 500pts and now the CPU score hovers in the low to mid 1300's. Also, on 4 seperate occasions it emitted a horrible high pitch noise that was only resolved by powering down the PC. I now have it back in the box waiting to have time to go out of my way to the retailer. Bah, enough about that.
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