Why do hot PC parts hurt performance?

[mettleh3d]

Procs NEED a heatsink/fan, higher end video cards ALL have a heatsink and a fan. Case cooling is an essential. I accept that and I try to maintain the lowest possible temperature on my system.

But I don't know why. A proc/gpu may slow or shut down if it gets too hot as a built-in safety feature. An overheated component may suffer permanent damage; I know this. Keeping the PC cool is something I do, but I'm not technically sure why. It seems obvious, but I just don't see it. Prolly analogous to cars?

Well, what im asking is: Why does overclocking make things hotter (the slower the cooler, the faster the hotter), and why are hot items bad for your system's health?

 

[SrGuapo]

If a processor of GPU gets too hot, it risks damaging itself in many ways. It could actually melt/damage parts of itself orr the motherboard. Also, heat causes substances to expand, and each element/substance expands differently. It is extremely difficult for me to explain, but basically things won't fit together exactly. It is the same way in cheapo cars where the pistons and valves are different materials. They work fine at normal temps, but when the engine warms up the actual piston can be bigger than the hole, and problems with wear and tear arrise.

 

[mettleh3d]

oh, the expanding idea makes sense.

 

[erorr404]

that is a good question. i would also like to know what the difference is between an overclocked, overvolted processor running at 50 C idle/60 C load on stock cooling and the same processor running with significantly lower temps with an expensive aftermarket cooling system. since the hotter temps i mentioned are not enough to do damage to a processor...

 

[SrGuapo]

IUnder 60C should be fine for any processor. I really would only start to worry when you start pushing 65-70. My winnie runs up to aound 56C at full load, and I don't mind at all. WIth the stock cooling, I could give it 1.55V or I would end up over 60C...

Identical CPUs at different temps should perform the same. Obviously this isn;t true for P4s when they throttle and such, but you undersdtand. My winchester at 60C will perofrm the same as another one at 40C...

 

[mettleh3d]

^^^^ excuse me, wth are you talking about? gg kthx

 

[angstsoldat]

he's trying to help you

 

[Geomagick]

It makes no difference really whether the components are hot or cold. The main things to look out for are if the temperatures really do go too hot then there will be stability issues with your system and possible failure of your hardware.

The main thing about using aftermarket cooling solutions is that they mean you can run the component harder than if you used standard cooling - but not in all cases, a big heatsink and fan assembly on a CPU won't guarante you overclocking success.

 

[ericlala]

When you are running a cpu at 60C+ overclocked and it is still not failing stress tests, you know that it can still go higher. That is when an aftermarket cooling solution comes in. With the new cooling, you can run at that same speed you were at a lower tempature and continue to overclock higher without being limited by the temperature.

However, if your cpu is already crashing stress tests and has not even reached 60C on the stock heatsink, there is no point in getting an aftermarket because the cpu is not limited by the temperature.

oops didn't answer your question. Overclocking make things hotter because one way to increase clock speed is adding voltage. More volts = more heat because V=IR meaning more volt = more resistance or to put it in another way, there is more friction inside.

 

[mettleh3d]

yeah i took physics in school, i remember V=IR. ic ic. thanks for the replies.

 

[cryptonomicon]

Originally posted by: mettleh3d
Well, what im asking is: Why does overclocking make things hotter (the slower the cooler, the faster the hotter), and why are hot items bad for your system's health?

changing cpu clock speeds wont change temps much, it's the added voltage, and if enough voltage is added it will easily saturate your heatsink, which can dramatically increase temperatures.

afaik:

CPU's- safe to 70C (under 55C recommended)

GPU's- safe to 90C (under 65C recommended)

 

[MobiusPizza]

There's some thread about this in detail in the highly technical forum

http://forums.anandtech.com/messageview...atid=50&threadid=1613117&enterthread=y

 

[PsYcHoCoW]

Originally posted by: ericlala
[...]
More volts = more heat because V=IR meaning more volt = more resistance or to put it in another way, there is more friction inside.
[...]

More volts != more resistance
More volts with same resistance = more current
More volts and more current = much more power
power => heat

And you can overclock without raising the voltage of the core. Ideal transistors inside the CPU would not generate more heat with just overclocking. It's because they are not "ideal" that they generate heat ; every transition to and from "conduct" to "don't conduct" (1 to 0, 0 to 1) is not instantaneous and makes the transistor get hot.

A transistor dissipates very little power (some due to leakage current) when it's fully on or off, but dissipates a lot when it's somewhere between these two states. The more times per second it is between on and off, the more it will get hot..

keeping things cool inside a computer does have benefits, but a few degrees are nothing to go crazy about if the computer runs well. As long as temps are in the safe range, "cool enough".

 

[Geomagick]

Originally posted by: cryptonomicon

Originally posted by: mettleh3d
Well, what im asking is: Why does overclocking make things hotter (the slower the cooler, the faster the hotter), and why are hot items bad for your system's health?

changing cpu clock speeds wont change temps much, it's the added voltage, and if enough voltage is added it will easily saturate your heatsink, which can dramatically increase temperatures.

afaik:

CPU's- safe to 70C (under 55C recommended)

GPU's- safe to 90C (under 65C recommended)

I have run a S478 Presscott at 93C and it was stable. It depends on the CPU some can handle more heat than others.

 

[Googer]

Don't forget guys that when you heat a material up it's resitstance increases in accordace with the temperature. More heat = less electricity that can flow: Resulting in a system crash.

Why do hot PC parts hurt performance?

I'ts not like a hot PC will result in lost FPS or 3D Marks. The same PC at a lower temperature will benchmark about the same as a hotter one (+/- less than 1% -standard margin of error).

You can run the same benchmark several times on a pc and get minor variations in the end resullts with out ever changing any of the system varibles.