Argument time - cooling down period for graphics or not?

[crossy]

Looking for opinions on a very trivial question...

When you've doing something graphics intensive (playing games), do you allow the graphics card time to cool down?

I've got two friends and one plays his game, then just shuts down when he's finished. The other checks a temperature reading on his card (think it's the Catalyst one) and leaves the system up for 5-10 minutes (timed shutdown) if the card's temperature is above 50C. The theory behind the timed shutdown being that this gives the graphics card's cooler time to dissipate the heat generated during gaming and bring the GPU's temperature down to "safe" levels.

So is friend A being cavalier and risking damage on his card, or is friend B being a bit obsessive? Is the best route somewhere in between.

EDIT: Forgot to mention - I tend to listen to the graphics card, if I can hear the fan noise then I leave the PC on until the card goes quiet - figuring that the card manufacturer has probably programmed the fan to switch to "quiet" mode only when the gpu is cool enough not to need a lot of cooling.

[Dooms]

Wow I can't believe someone does this? or am I missing something that everyone does and no-one has told me?

I monitor temps while getting a stable overclock and again once we get some hot weather again apart from that as long as my CPU/GPU aren't setting themselves on fire I don't pay them any attention.

[b0redom]

So is friend A being cavalier and risking damage on his card, or is friend B being a bit obsessive? Is the best route somewhere in between.

Electronics are rated for use at a certain temperature. Provided you're within that envelope, all that leaving the computer on is doing is cooling the component more quickly. If you turn off your PC, the remaining heat will still dissipate, just by radiation rather than convection.

If you're operating the electronics outside their rated thermal envelope, you have significantly bigger problems than whether to burn 5 minutes more power or not.

[Domestic_Ginger]

Usually you close the game before shutting down windows; card hits 2d mode, comparatively little heat is generated and the card begins to cool down.

[jim]

If it's true then we ought to all have a UPS because instant power off mid gaming would be suicidal. I'm guessing it's not true then.

[DanceswithUnix]

Think of the thermal inertia of a gpu chip vs the amount of energy stored in the heatsink. Most of the heat you are getting rid of is probably in the heatsink once you have quit the game.

Besides, I find once out of a game the fan speed shuts down pretty fast anyway, they drop from there to zero doesn't seem scary.

[scaryjim]

I can kind of understand the concept behind letting the GPU actively cool down to reach a lower temperature faster, but it's not really going to make any practical difference to the life of your GPU (unless it's already running dangerously hot, at which point you have a different problem). Remember people baked their nvidia GPUs in the oven to fix them not so long ago. So in a slightly warm box that's not generating any additional heat so will cool down naturally anyway? Not going to be a problem...

[jimbouk]

I guess the theory comes from hot running car engines. The difference is the coolant flow was important as much as the fan running. Stopped the 'hot spots' on old turbo engines that could get rather toasty.

For a small GPU die in contact with the heatsink this won't matter, it's not like you're exploding things inside them.

[peterb]

I can see some logic in letting the card cool down gently to avoid thermal shock - sudden temperature changes may cause mechanical stress to the soldered joints, which overtime may lead to failure. How likely that is is hard to say, and there is the question of whether leaving the power on allows the GPU to cool down more slowly and evenly than just powering off.

It certainly won't do any harm, but it would be interesting to stick a thermometer probe on the heatsink and in the computer case itself and monitor the temperatures under both situations.

Please report back when you have done so!

[DanceswithUnix]

I guess the theory comes from hot running car engines. The difference is the coolant flow was important as much as the fan running. Stopped the 'hot spots' on old turbo engines that could get rather toasty.

I always thought it odd that cars can keep the fans running, cooling down the radiator, despite the engine being off and hence the mechanical coolant pump not being on. (edit to add: That is probably just to save the cost of a relay, you won't run a pair of big fans directly off the ignition switch).

Anyway, there used to be a device you could buy to keep the PC fans running for a while after you power off. Never saw the point myself, but if it gives someone a warm fuzzy feeling...

[jimbouk]

I always thought it odd that cars can keep the fans running, cooling down the radiator, despite the engine being off and hence the mechanical coolant pump not being on.

That as well, for general engine cooling. With my old 924 turbo it was good practice to let the engine cool down running after a blast to avoid hot spots, as well as this the thermostat had an line from the battery (as well as the ignition) to keep running after shutdown above a temperature threshold. The latter is generally applicable rather than being specific to hotter engines.

[Ttaskmaster]

I stop gaming and usually do a few less intensive things, like playing Freecell for a bit before shutting down anyway, so not an issue. Plus it's freezing in our house as we don't put the heating on.

[Sheen]

I wonder where did they get that theory from? Anyway, GPU temp is dropping in seconds after you exit the gpu intensive game/software, so by the time when windows shuts down it would be much cooler anyway.

[mikeo01]

I have a nice big "Power" button on my keyboard if I really am finished

I highly doubt it matters what you do to be honest; the PCB, solder, silicon are all rated and can withstand different heat conditions.

I assume cutting the power instantly may be bad, not completely sure wise, something about not letting the current flow back out? I duno.

GPUs seem to rapidly cool down even if there's a slightly hiccup in the game

[peterb]

I always thought it odd that cars can keep the fans running, cooling down the radiator, despite the engine being off and hence the mechanical coolant pump not being on. (edit to add: That is probably just to save the cost of a relay, you won't run a pair of big fans directly off the ignition switch).

You still get some convection (thermosyphon) effects with the coolant circulating through the radiator even with the mechanical pump stopped, and I think this is to stop the temperature rising in the radiator because of that.

That as well, for general engine cooling. With my old 924 turbo it was good practice to let the engine cool down running after a blast to avoid hot spots, as well as this the thermostat had an line from the battery (as well as the ignition) to keep running after shutdown above a temperature threshold. The latter is generally applicable rather than being specific to hotter engines.

With turbos that is usually to ensure that there is still a supply of oil to the turbo bearings while it spins down after a blast! Turning the engine off stops the oil supply and with the turbo spinning at 50,000 RPM or more, that isn't a good idea!

I highly doubt it matters what you do to be honest; the PCB, solder, silicon are all rated and can withstand different heat conditions.

It isn't necessarily absolute temperature, but the change and the rate of change. (Put a hot glass in cold water for example)

assume cutting the power instantly may be bad, not completely sure wise, something about not letting the current flow back out? I duno.

Powering down instantly (without shutting the OS down normally) can be bad because the data caches may not have been written back to disk, with the risk of data loss.

[Domestic_Ginger]

I would have thought intensive 3d to 2d is a bigger jump than 2d to off. Therefore loading up a and exiting a game would be a bigger change than turning the pc off. rt (say 20) to about 30-40 is not sa big as 30-40 to say 70.


With reagrds to the fan speed it'll be propottional to twmperature but in order to avoid annoying changes in speed it'll stay at the higher speeds until the temperature is something like 8C lower. Hysteresis I think its called.