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Hi,

During graphically intensive parts of games I'm getting a sudden drop in fps, and the total power draw on my system is dropping by about 50v. I have a phenom II quad core cpu and a HD 4870 graphics card. I've checked both for overheating, the cpu does not break 45C and the GPU maxes out around 60C. Whats going on here? Otherwise my system runs fine. Am i just maxing out my GPU? In MSI afterburner it says max gpu usage is 101% haha.

clapton924 wrote:

the total power draw on my system is dropping by about 50v

Umm... huh?

Do you mean 50W, or something else entirely? If the line voltage was dropping by 50V the system would probably be shutting down completely (and this would also be an indication of serious problems with your house wiring).

I'm guessing that either something is throttling due to temperature issues (somewhat unlikely if your temp sensors are working properly, as your temps look OK), or the 12V rail supplying the video card is sagging enough under load that the GPU is falling back to a lower power mode. Are you sure the PCIe power connector is firmly seated? What are your PSU specs?

I was just going to say "inadequate PSU" which I've seen with 100W graphics cards shoved into Dell workstations with "325W" PSUs. I guess those 6-pin PCI-e power connectors are just for show in some of the Dells :\

There is some throttling happening on either the CPU, GPU or both. If you run dual monitors, put GPUZ and CPUZ up on the second screen while in a 3D application and check to see if the clock frequencies drop.

just brew it! wrote:

clapton924 wrote:

the total power draw on my system is dropping by about 50v

Umm... huh?

Do you mean 50W, or something else entirely? If the line voltage was dropping by 50V the system would probably be shutting down completely (and this would also be an indication of serious problems with your house wiring).

I was going to say something similar. I can imagine some wattage changes, but losing voltage is a very very bad sign.

Sorry guys, I meant that the total system power draw is dropping by about 50W not volts. Once the action clears, the watts go right back to where they were. Max system draw is about 260W and I'm seeing sudden plunges to about 205W. My PSU is a relatively new Antec Neo 520W. I Imagine it is something with the GPU...no other component on my computer draws that much power. Surfing the net my total system draw is about 150W.

wingless wrote:

put GPUZ and CPUZ up on the second screen while in a 3D application and check to see if the clock frequencies drop

That's the first step. Verify whether or not clocks are dropping. If clocks are dropping, the most common culprit is thermal throttling. What program/s can overlay GPU temp and clock info on top of the game screen? I know they're out there.

You can most likely reproduce this throttling effect with Prime95 (will load your CPU to 100%) and/or MSI Kombustor or Furmark (either program will load your GPU to 100%) to name a couple. Using a stress testing program will allow you to use temperature/clock monitoring programs like CPUz and GPUz in front of the stress testing window. (hepful if you only have one monitor) Stress testing programs will give you a constant load and eliminate any possible in-game issues that may be causing these problems. (isolate the variables)

If throttling is happening, you'll need to get the possible overheating issue isolated.
1) take the side panel off your case
2) clean the GPU & CPU heatsink with canned air
3) set a box fan or ~9" round fan next to your case, pointing into the case. If you can, lock the CPU and GPU fans to 100%
That should give you the best chance of avoiding clock throttling due to any overheating issues.

Report back once you've tried these.

Here is some more info for you guys. Running CPUZ and GPUZ revealed that I'm getting no fluctuation in CPU speed/voltage or GPU core speed or memory speed. However, according to GPUZ I'm getting huge plunges in GPU utilization during these fps/system power drops. The GPU usage is going along steady around 95% ulilization, then dropping way down to 25% utilization during these graphic heavy times. Any one seen this before?