Low CPU voltage readings after single core ---> dual core install

[WhipperSnapper]

I just finished upgrading my computer from a single-core Socket 939 Opteron 148 to a dual core Athlon X2 4400. Funny thing is, using my motherboard's CPU monitor, it's now showing unusually low voltages and I'm using a voltage similar to what I used for the Opteron. When I had the Opteron the voltage that it would read was about the same as what I had set in the BIOS, but with the dual core CPU installed, it's reading lower voltages.

For example, a setting of 1.425 V shows readings of 1.34 V. Consequently, Stress Prime Orthos quickly reported errors when I had it set at 1.4 V and I saw readings of 1.30 V.

Isn't the stock voltage for a Socket 939 dual core Athlon X2 supposed to be 1.35 V?

So far I haven't received an error from Stress Prime Ortho at 1.425 V in the BIOS (at 11 x 210). Maybe I just need to keep upping the CPU voltage? Should I be concerned about taking it up to 1.5 V? Is it unusual for dual core CPUs to end up reducing the CPU voltage a bit, in which case a setting of 1.5 V might be 1.4 V in reality? Can I trust my mobo's voltage readings? CPU-Z is also reporting low voltages.

(Mobo is an Epox +9NPA- Ultra.)

 

[myocardia]

Originally posted by: WhipperSnapper
Isn't the stock voltage for a Socket 939 dual core Athlon X2 supposed to be 1.35 V?

Yes, it's 1.35v. The reason your indicated vcore is lower with the X2 is because you're not running one core, you're running two now, and the motherboard is now having to supply a much higher amperage, even though it's a lower vcore. And yeah, up to ~1.40-1.45v is okay with the X2's. They are 90nm, after all.

 

[WhipperSnapper]

Gah, I'm at about 1.50-1.53 V. Oh well. Idles around 36 degrees C and gets up to about 47 degrees C when stressed. Oh well, if it dies it dies ($66 shipped off of eBay) and I'll get one that overclocks better. Currently at 11 x 230 (2.53 Ghz) and a setting of 1.575 V in the BIOS.

 

[VirtualLarry]

I had the opposite problem with a friend's rig. Dropped in an X2 3800+, and under load, the vcore goes up, from the BIOS set 1.35v to nearly 1.4v.

 

[GuitarDaddy]

I upgraded my sons 9NPA ultra from single core to dual core and also had to dramatically loosen the timings to acheive the same overclock. The only difference was I also upgraded his ram from 2x512 to 2x1gb at the same time, so I just chalked it up to the change from 512mb sticks to 1gb requiring the looser timings. But in reality I was probably facing the same thing your are, with two cores and an onboard memory controller under the hood overclocking seems to stress the memory controller much more than single core chips.

I use coretemp to monitor temps