My x2 3800+ AM2 is at full load but still 1.1 volts

[Kuroyama]

I bought a new x2 3800+ AM2 processor a few days ago and noticed a strange quirk. I have Cool 'n' Quiet enabled in BIOS and also installed the AMD Cool 'n' Quiet driver in WinXP.

I ran the computer for 10 hours with Rosetta@Home and Einstein@Home. Both cores of the CPU were running at 100% the entire time, but CPU-Z reports the voltage is stable at 1.168V. Multiplier and HT are at 10.0 and ~200 (HT varies from 200.0 to 200.4). Voltage and multiplier never change.

Now, strangely, when I shut down the @Home tasks the CPU load goes from 100% nearly to zero, but CPU-Z reports voltage is now fairly stable 1.200V (with occasional small jumps). Again, multiplier and HT are at 10.0 and ~200. The only thing that works as expected is that temperature quickly drops by a significant amount.

What's going on here? Heavy CPU usage seems to result in lower voltage! And the voltage never goes over 1.20V, when it should max at 1.35V under load. Any ideas?

 

[tbike06]

It's telling you to overclock it.

 

[Kuroyama]

I overclocked each of my builds in the last five years, but this time I've decided to go for a small (Antec Aria) quiet PC. Wanted one of the paper-launched Energy Efficient Athlons, but finally gave up on waiting.

While overclocking I've managed to burn out an Athlon XP 1700+ (a voltage regulator mod gone bad), crack a Duron (my downgrade after roasting the 1700+), burn our a GeForce3 (tied up the wires inside to make things pretty and ended up pulling out the power on the GeForce cooling fan), and one motherboard (don't know what happened), so I'm hoping if I don't mess around this time then I can save a bit of money.

 

[Kuroyama]

Well, I went to AMD's site and installed their latest Cool 'n' Quiet driver, and their dashboard program to see how much power it's saving me. AMD's software reports the power use is always at 1.300 volts, no matter how much or how little I do. So CPU-Z must be wrong, although it's still weird how it behaves.

Now my problem is how to get Cool 'n' Quiet to actually change the frequency and/or voltage automatically like it's supposed to.

 

[Kuroyama]

Finally discovered that I have to go to Control Panel -> Power Management -> Minimal Power Management. Now the CPU and voltage clock back like they should.

 

[5t3v0]

Dont use the AMD dashboard. It is completely inaccurate. Use your Asus supplied montoring tool or a third part app like cpu-z or Speedfan. I tried the dashboard & it read 1.1v when it was in fact 1.35v (down clocked) and then 1.4v when it was 1.55v (fully clocked). Also the temperature read 26C when it was actually 46C.

 

[Furen]

The AMD tool reads the PState voltage, not your actual voltage. If you overclocked and you have a voltage increase over the PState then, of course, it'll be inaccurate. I've found that CPUz is horribly inaccurate with AM2 chips.

 

[imported_inspire]

Originally posted by: Furen
I've found that CPUz is horribly inaccurate with AM2 chips.

Ditto.