Does anyone have any idea on how hot an average desktop computer gets?

Or do you know how much electricity a normal computer fan uses in a hour? Thanks.

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orksecurity8 years ago
Depends on the speed of the processor (and video card), and depends on how hard you're working them. As Sean said, the fan's a minor power draw compared to computation. Look at the power ratings on PCs. Almost all that energy winds up as heat. If your PC has a 90W power supply, you've got a 90W heater. Faster machines can run considerably above that. Yes, the machine can cook itself if the airflow is insufficient. Laptops are particularly at risk, since they're so compact and have tiny fans.
And that's probably a large part of why a lot of intense gamers prefer a desktop computer, not only because of better performance because of on average a desktop is more powerful than a laptop, but it also often performs better because it doesn't get as hot, and depending on your components, heat can have a major impact on your performance. I've noticed with my desktop, that the warmer the room is, the slower my computer will run.
seandogue8 years ago
the computer fan doesn't use all that much power. No I can't call out specs, but they run @ 12 or 5V in the 50-100mA range when full on. My desktop tower is blowing ~80degree (F) air out the power supply but otherwise it's at room temperature...I'm sure the uP and graphic processor are warm, but I'm not going to attempt touching them, since they're capped with their own fans. If it's really hot, then you probably need to open it up and clean it using compressed air (those bottles they sell at computer stores and radio shacks). and a vacuum cleaner to absorb the dust.
To be 100% clear on this issue, a desktop should not be getting "hot", where hot would be >100 degrees F. If it is, then you are not providing enough cooling or the ambient conditions are far too warm for it to function properly.

I do not believe you intended to ask about laptops, as they are simply NOT desktop computers, so I have avoided talking about them, since they are Non-sequitur, or illogical in answering such a question.

Presumably your PC is too warm. If cleaning it does not help, and especially if you've installed a more powerful graphics card or other components recently, then you may want to invest in another case fan to assist in moving ambient air thru the case to cool the system.

If you have a messy cable arrangement inside the case, consider tying it up to allow the air to flow more freely thru the case. Make sure when cleaning the computer that your fans are all working properly and if necessary, remove and individually clean them. If their blades are gummed up, they will not efficiently move air.
Hycro seandogue7 years ago
I've seen some newer desktops, the ones built at the factory, shipped to the store, and you buy them as a pre-made product, that have little ventilation at all, and are so compact, that I could almost fit one inside the case for my custom-built desktop computer, and I do have four case fans, the one in the front is to supply fresh air to my hard drives (using a fan mounting spot already there), two on the side, with one supplying fresh, cool air to the processor's cooling fan, and one supplying fresh, cool air to my GFX card and sound card, then I have one in the back as near the top as I can get it (maybe should have a second one there, to allow for the airflow of the others??) oh, and my PSU came with two fans built in, one to suck air out of the case and into the PSU, and the other for the PSU's exhaust...often the exhaust from the case fan is around 80 F (I'm a Celscius user, but I've noticed most are Farenheit users on here) and the exhaust from the PSU is around 85-90F. Processor runs usually around 80-85F with a moderate load (2.9GHz AMD Athlon X2 64) and the GFX card runs around 140F with little or no load, and the highest I've seen it was just under 176F, and the GPU and GFX RAM are overclocked. I often open the case and clean the dust out, 'cept in the PSU, because I have to remove it for that, and I don't really want to redo my wire management too often.
Regarding adding case fans: this is a hotly-debated point (pardon the pun) in the PC enthusiast community. It turns out that AMD did a laboratory study into this issue back in 2005, and their findings demonstrated that the most effective set up for fans is far and away the single fan set-up in the top-rear of the tower. This, of course, should never count the PSU fan which is only working to cool itself. Personally, I have several fans - but my setup is somewhat different than most, and I have some specific reasons. For almost all users, I would recommend the single-fan setup since it has science behind it.
Well...I don't know all that much about the PC enthusiast community. My background is limited to nearly two hundred professional installs in laboratory and industrial environments, so I must admit I'm weak on the amateur circuit. In the professional circuit, we usually stick with thermodynamics to guide us. Might not be the right way to go, but that's all I have to work with. We place cooling devices where we find hotspots for local cooling, and we augment that by using bulk transport devices for maintenance of ambient conditions. In the case of enclosures, Fans are the device we use for bulk transport when something a bit more heavy handed isn't required. As I stated, If the system is clean, and if the user has augmented his/her system with new capabilities or replaced original components with higher wattage devices, or for that matter, if the author has begun over-clocking his/her processor, (although this entire thread has become academic, since the author said nothing about actually having a problem), then the user will need to upgrade or augment their bulk transport to maintain convective flow within the computer enclosure. It's really not a question of oxygen free audio cable, LP vs CD or any of the other enthusiast issues that get beaten to death by the amateur crew. And none of it is mind boggling. Maybe that's what separates the enthusiast and professional communities. In my realm, we simply address the issue and move on to other pressing problems, whereas the enthusiasts like to debate. Sometimes I think they like the debate more than getting results.
I agree with this in a specialized setup, and no one can argue with the laws of thermodynamics (no matter how many free energy kooks we see on this site). However, in almost all computer cases one must think of it as a sealed box with only the fan ports for intake and exhaust. While some cases sport several side ports for fans, if you have a traditional air-cooled setup with no overclocking then the ideal airflow resembles an "S" shape where cool air comes in the bottom front, snakes up past the VGA and chipset, then turns again past the CPU on its way out the top rear.

As discovered in the AMD study, this "S" shaped airflow occurs just fine in a standard rig with only one exhaust fan in the top rear. Even adding an intake fan on the bottom front creates too much turbulence to maintain this path, and the net result is lowered efficiency. The effect is even worse with the addition of side fans.

The debate is sparked from whether its more important to obey the findings of studies like this, or just flood the case with as much outside air as possible since, despite turbulence, cool air is cool air and you can't have too much of a good thing like that. As long as the same amount of air is pushed out the back, some argue that this is the better way to go. The argument is whether this approach actually creates hot and cold spots or not - it's more of an argument of fluid dynamics than thermodynamics.

The reason my setup differs is that I use water cooling for the CPU and VGA. The chipset doesn't work too hard on my computer nor does the RAM, since I'm not overclocking (the water cooling is a quieter solution). I do have several case fans, but they are low-flow and whisper silent. Because of this, my CPU/VGA temperatures hardly ever break 80o F, and even under stress testing my RAM is cool to the touch.

And I also agree with you that it doesn't have to be mind boggling. For the interest of the question, since I wasn't sure what the author was going for, I named some of the more common variables that would be obvious to a professional but overwhelming and extraneous complication for the amateur.

For what it's worth, oxygen-free cable only prevents corrosion and is desirable for longer life but does not affect audio quality. LP is great for nostalgia (and I'm a vinyl lover) but even under archival conditions does not have the sound quality of CD (and I've proven this scientifically to quell arguments from those who misinterpret the Nyquist theorem to explain otherwise).
lemonie8 years ago
lemonie8 years ago
They can get quite hot, a CPU/GPU at full whack can be 100W plus (depending). Why are you asking? Your machine, general interest? L
Bostonians (author)  lemonie8 years ago
Just curious. Thanks
As to the subject of heat output, I can tell you that it entirely depends on a number of factors. The first factor to consider is the total power consumption of the computer (primarily, the power supply and CPU tend to generate the most heat, followed by the graphics card, chipset, and hard drives - usually in that order). Next is the percentage of inefficiency (the amount of electricity wasted as heat energy, which is fairly high and varies per component). Then you must consider the efficiency of heat transfer from the device to the cooling system (almost always through a heat sink into air), the incoming temperature of coolant (almost always air), the flow rate of coolant, &c.

While this may seem rather incalculable and somewhat mind boggling, I can tell you that these specific factors are at the forefront of a certain breed of computer enthusiasts' minds (go here for a wealth of information on the topic). However, you can figure things out in a more general way if you wish not to devote your entire life to the pursuit of quieter, cooler operation (at the expense of your sanity).

Desktop computers can get really hot; temperature tolerances vary for different components, but Sean is generally correct (I wouldn't start worrying too much unless the exhaust temperature exceeds 120o F). Some ways to increase cooling efficiency are (in order of simplest to most complex):

1. Clean your computer thoroughly with a vacuum, Q-tips, toothbrush, and compressed air to remove dust. Dust is an insulator and prevents heat exchange from the components to the air around them - this results in higher temperatures, stability and performance issues, and drastically decreased lifespan.
2. Manage your wires. Using zip ties, creative routing, &c, try to run the wires as close to the edges of the case as possible (allowing a larger, unobstructed air cavity in the middle of the case). A tangled mess of wires will create turbulence and air stagnation inside the case, resulting in decreased air flow and an increase of dust buildup.
3. Determine that your power supply is ample enough to easily power your computer. A surprising number of computers do not have an adequate power supply, and as a result the PSU runs hotter than it should. Check the sticker on the side of the supply for constant wattage, then find the specs for the components in your system (remember to include the CPU, motherboard, and hard drives) and add the peak or maximum wattage of those parts; if the components use a total maximum of 75% or more of your constant power from the PSU, consider getting a better one.
4. Use power management in your OS to control how hard the CPU works. Almost all PC users run their CPU's full-throttle - even at idle (most leave their computer on 24/7 and are away from it the majority of the day). In Windows, go to Start>Control Panel, and open "Power Options"; if "Always On" or "Home/Office" are selected, you're an energy hog. Change this to "Minimal Power Management", thereby invoking energy-saving features built into hardware/software. This greatly reduces energy consumption (making you greener and cooler, and leaving you with about $12/month savings on your electric bill on average).
5. Invest in a highly-rated aftermarket CPU heat sink and fan. The link I provided is an incredible resource for this. Remember though that doing this is frowned upon by CPU and motherboard manufacturers, and in some instances will void your warranties (due to the fact that people either install them incorrectly or the heavier ones cause stress on the socket/motherboard).
6. Consider alternative cooling methods such as water-cooling. This is more recommended for the advanced user, and is a lot easier when building a PC from the ground up. There are many kits available on the market that make installation pretty easy.
7. Consider underclocking/undervolting your processor. This is more recommended for the advanced user, but will yield even more energy savings with little to no impact on performance (I'm currently working on an Instructable for this).

As for the energy consumption of a case fan, this too varies. Most modern fans/motherboards use 12V, but control the speed of the fan using PWM (pulse-width modulation). This effectively reduces the actual supply voltage going to the fan, since it is not actually DC. However, as a general rule, Sean is also right on the money.

I hope I answered your questions; if you need help, let me know.
ReCreate8 years ago
Depending on the Type of heatsink used, It can range from 70 Degrees Fahrenheit to 200 Degrees. Mostly while not under stress, the CPU temperature can get as low as 5 degrees above room temperature. While Under stress the Temperature can go up to 150 Degrees on some CPU's and even near 200 Degrees on others.