# Laptop cooling Qs **URL:** \ **Category:** Factual Questions\ **Created:** [May 26, 2012, 4:02am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138 "2012-05-26T04:02:51Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [May 26, 2012, 4:02am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138/1 "2012-05-26T04:02:51Z")
My laptop runs much cooler when it’s not plugged in. Today, I went through and copied all the “battery power” power management settings over to the “plugged in” power management settings–but it doesn’t seem to have made a difference. It still runs much cooler when it’s not plugged in. Any idea whether I should in theory be able to get it to run just as cool plugged in as when it’s using the battery? Or is this impossible for some reason? Moreover, today, for a reason that I do not know, it started running _much hotter_ than it used to when plugged in. (It has always run hotter when plugged in, but only today did it, suddenly, begin running _alot_ hotter.) What could cause a _sudden_ jump in running temp like this? (No new applications have been installed.) I am now only able to play Diablo III, even on the absolute lowest graphics settings, for about five minutes at a time (plugged in) before it gets into danger-zone temperatures. Yes, this is all about me playing a game. ---
**Author:** ![Satellite\_Guy](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@Satellite\_Guy](https://boards.straightdope.com/u/Satellite_Guy)\ **Post date:** [May 26, 2012, 5:01am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138/2 "2012-05-26T05:01:10Z")
Do you think it may have something to do with your having changed the battery power management settings? Also, I’ve always found my laptop to run pretty hot. I recently bought one of those laptop cooling pads (I got a [dirt-cheap](http://www.shopxscargo.com/product_catalogue/cat_product_details.asp?category_id=44&product_code=25363&sub_category_1_id=175&category=Computer%20Accessories) one), and it’s brought the temps down from **almost hot enough to not want to touch the cooling vent** , to **barely feel any warmth at all**. ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [May 26, 2012, 5:44am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138/3 "2012-05-26T05:44:34Z")
Well, first of all, it’s entirely normal that it would run hotter when plugged-in and charging. The charging of the battery will generate heat. Also, as you discovered, there are different default power profiles for “plugged-in” and “battery” so that everything is running at full speed when plugged-in. That also generates more heat as opposed to when it’s running on battery and the CPU runs at a lower speed, and the display is dimmer, so as to conserve battery power. And when you’re doing something that is CPU, GPU and/or disk drive intensive, such as running a game like D3, that will also generate more heat. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [May 26, 2012, 5:50am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138/4 "2012-05-26T05:50:04Z")
How about plugging in, but removing the battery? ---
**Author:** ![Heracles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heracles/32/487_2.png) [@Heracles](https://boards.straightdope.com/u/Heracles)\ **Post date:** [May 26, 2012, 9:41am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138/5 "2012-05-26T09:41:59Z")
A modern Windows PC will spend some time doing silly things (indexing files, running badly-written code from an open Web page, running malware, etc.) using a large portion of its CPU power, so in general it can get hot pretty much at random. When it does, use the Task Manager to find out why (in the “Processes” tab, there’s a column for “CPU” use which generally correlates with heat generation). You speak of a “danger zone”, but is it the laptop itself that is in danger or is it your body? Manufacturers usually design computers so that they can’t really fail from overheating, even if running CPU- and GPU-intensive tasks for hours on end. If it’s only a comfort thing, try to rest the laptop on a heat-tolerant table (make sure it’s a hard surface so that air can circulate underneath). If you really must put it on your lap, try a laptop tray similar to [these](http://www.kico-laptrays.co.uk/laptop-lap-trays.html). ---
**Author:** ![Cicero](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cicero/32/3594_2.png) [@Cicero](https://boards.straightdope.com/u/Cicero)\ **Post date:** [May 26, 2012, 9:59am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138/6 "2012-05-26T09:59:22Z")
How did you measure the temperature of the laptop (I’m just curious- I have no knowledge of these things). I run Civ V for hours at a time on a laptop and it does get hot - even with a cooling pad. And as I typed this the whole damn thing froze- spmething that never happened before. Curse this thread! ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [May 26, 2012, 11:33am UTC](https://boards.straightdope.com/t/laptop-cooling-qs/623138/7 "2012-05-26T11:33:07Z")
> [@Frylock](#): > > My laptop runs much cooler when it’s not plugged in. Today, I went through and copied all the “battery power” power management settings over to the “plugged in” power management settings–but it doesn’t seem to have made a difference. It still runs much cooler when it’s not plugged in. Any idea whether I should in theory be able to get it to run just as cool plugged in as when it’s using the battery? Or is this impossible for some reason? For years now, CPUs and GPUs have had the ability to lower their clock speed and voltage on the fly. Laptops usually will run the chips at a lower/lowest setting when on battery by default. It’s possible the settings you copied over didn’t affect this. > [@](#): > > Moreover, today, for a reason that I do not know, it started running _much hotter_ than it used to when plugged in. (It has always run hotter when plugged in, but only today did it, suddenly, begin running _alot_ hotter.) What could cause a _sudden_ jump in running temp like this? (No new applications have been installed.) > > I am now only able to play Diablo III, even on the absolute lowest graphics settings, for about five minutes at a time (plugged in) before it gets into danger-zone temperatures. > > Yes, this is all about me playing a game. How old is it? Fan could be blocked or something. DIII is pretty much going to max out the CPU and GPU so if airflow is reduced, overheating is likely.