UNDERclocking Graphics Card

[NeoDreamer]

My nVidia GeForce 8800 GT 512 MB(by eVGA) runs quite hot at 59 C on summer days. I decided to underclock it whilst doing 2D stuff. I sensed no decrease in performance when I did so, because this card is a beast. The problem is that I only saw a maximum of 3 C decrease in temperature.

Stock:

core: 600 MHz
shader: 1500 MHz
memory: 900 Mhz


Underclock:

core: 300 MHz
shader: 750 MHz
memory: 450 Mhz


Does anyone understand the physics behind this? I've halved all frequencies, so shouldn't the temperature be dropping more than a measly 3 C?

[Templarian]

The safe running temperature is 85°C (max or so says nvidia tech) for an 8800 you are NO WHERE near its limit. :lol:

I've gotten my 8400M in my laptop to 93°C once. Throw some CRYSIS in that thing and really get the thing up there.

//edit plus nvidia's have fail safes (probably at 90°C).

[Theros]

um...Like temp said, your perfectly fine temperature wise.

[GW02]

Yeah, 52-59 degrees C is fairly standard operating procedure for high-end NVIDIA cards.

However, to answer your question directly, your culprit is likely that your card is sensing that it's running lighter, so it's also dropping your fanspeed to save power and reduce noise (there's usually a target temp for each profile). If you undervolt in combination with locking fanspeed (remember to turn it back to auto when playing a game!) you should see your temps drop to 51 degrees or so.

[NeoDreamer]

The temps that I've listed are for when I'm not gaming. It is high compared to the temps some nerds posted on www.tomshardware.com . I don't have a fancy case. It only has two 120mm fans. I'd just like to lower the temp in a simple manner, instead of pimping out my case.

[NeoDreamer]

likely that your card is sensing that it's running lighter, so it's also dropping your fanspeed to save power and reduce noise

When I was monitoring my temperature, I made sure that the fan speed was constantly at 50%. I have setup my fan to change speeds based on core temperature, not core clock.

[Theros]

The temps that I've listed are for when I'm not gaming. It is high compared to the temps some nerds posted on www.tomshardware.com (http://www.tomshardware.com) . I don't have a fancy case. It only has two 120mm fans. I'd just like to lower the temp in a simple manner, instead of pimping out my case.

Honsetly, who cares if its high according to some benchmarks some "nerds" on tomshardware.com have. What you have falls within the VERY FINE range of GPU temps. Only when it reaches 90+ Celcius should you start to worry. Why would you downclock it even if its idling at that temp, nothing wrong with it.

[NeoDreamer]

Increase the lifespan and decrease power usage.

I feel like it's my duty to not waste electricity. I'm not gaming 24/7. I just game like once a week.

[mlk]

underclocking it will save you electricity so I think it's a good idea anyhow...

are you sure temperature levels are linear in proportion to clock speeds ?

[NeoDreamer]

That's what I'd like to know. We need a physicists in here to explain the relationship between power usage, clock speeds, and temperature.

[GW02]

The answer is no; there isn't a direct correlation, and for a simpler reason than you might think.

While under/over-volting will have a reasonably direct correlation with the amount of power supplied to your clock circuitry, the clock circuitry only controls how quickly the processor turns over each stage of the pipeline. The rest of the circuitry is on a separate power plane, and that voltage is on an as-needed basis, controlled by an entirely separate subsystem.

{edit: overall, as long as you underclock your GPU (which should be happening automatically anyway, though perhaps not as deeply as you are) the power consumption tradeoffs shouldn't matter in terms of the temperature.}

[Theros]

Increase the lifespan and decrease power usage.

I feel like it's my duty to not waste electricity. I'm not gaming 24/7. I just game like once a week.

I'm pretty sure that won't really help the lifespan of the GPU at all. Plus, I doubt you will really save that much power honsetly...not worth the effort IMO.

[randomagain]

I think what may be going on is that you can UNDERclock

but you are just setting a fluid limit, so its actually still running in anticipation of a full speed spike

hence the minor drop in temp