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8th December 2017, 21:26 | #1281 | Link | |
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Clearly, it's time for Thermodynamics 101 with T. Fluff, PhD (I hold a doctorate in The Science of Telling People they are Wrong on the Internet) Let's review the fundamentals first, yeah? This is all high school physics, so you should probably know this. The laws of thermodynamics tell us two important things relevant to this discussion, namely that a) energy can never be created or destroyed (so if we put some energy into a system we must get the same amount of energy out), and b) entropy tends to increase, so if you have two bodies with different temperatures in thermic contact with each other energy will flow from the hotter one to the colder one until they reach equilibrium. Now on to what this means in practice. In a computer, we input electrical energy. Some of this energy is converted to kinetic energy (to spin harddrive platters and fans), and some is converted to electromagnetic radiation mainly in the form of visible light (in LED's and in the monitor), but the vast majority of it eventually decays to thermal energy after being used to push some electrons around through a bunch of transistors. This heat has to go somewhere, and that somewhere eventually ends up being the air of the room. In a moment, we will calculate the magnitude of this effect, but first we need to clear up a misconception. The TDP of a processor is an estimated ballpark number of the amount of thermal energy it generates in a given fictive scenario that's supposed to represent a typical peak workload. In any other scenario (such as most scenarios you'll find in reality), the actual amount of heat generated is different - the TDP is only supposed to be a rough estimate of the maximum sustained heat generation possible. The TDP number has absolutely nothing to do with any of the following: - amount of heat generated at idle - amount of electrical power consumed at idle - temperature of the silicon in any given situation In practice, the amount of thermal energy generated by a processor is pretty much equivalent to its electrical power consumption because almost all of the electrical energy quickly decays to heat. The first law of thermodynamics also tells us that we cannot possibly get more thermal energy out of a processor than the amount of electrical energy we put into it. If you look at the processor's power consumption then, you will have a good idea of how much heat it's producing. Modern CPU's and GPU's are very good at clocking down (and more importantly, reducing the voltage) at idle and so you'll see a typical idle power consumption of 10-20 watts. The power consumption - and by extension, thermal energy generation - still doesn't have anything to do with the temperature of the chip, though. See, temperature is a measure of energy, but it's a measure of stored energy. Two chips consuming the same amount of electrical energy will heat your room exactly the same, even if one is twice as hot as the other. The only thing that's different in the hotter chip is that the energy stays in it for longer before dissipating into the room. Speaking of energy storage, to calculate the heating effect of an idling CPU we first need to discuss specific heat capacity. Different substances can store different amounts of thermal energy, and the specific heat capacity is a measure of how much energy a substance can store per unit mass. Or, in more practical terms - heating one kilogram of water by one degree Kelvin takes about four times as much energy as heating one kilogram of air by one degree Kelvin. Many metals have very low specific heat capacity, meaning it takes little energy to heat them up, but conversely that also means they're bad at retaining that energy and they quickly cool down again. For example, copper (commonly used in heatsinks because of its excellent thermal conductivity) has a specific heat capacity of 0.385 J/gK (joules per gram kelvin difference - it takes 0.385 joules of energy to heat one gram of copper by one degree kelvin). Air at typical indoor conditions has a specific heat capacity of about 1.01 J/gK. If we then assume a spherical CPU in a vacuum... uh, no, I mean, a small 30 square meter studio apartment with the minimum indoor ceiling height of 2.4 meters allowed by the building code in these parts, we can easily calculate that the 72 cubic meters of air inside weighs around 92 kilograms. Given the previously discussed specific heat capacity, heating 92 kilograms of air by one degree kelvin (or equivalently in this case, one degree celsius) takes 92.9 kilojoules of energy. Now, a watt is a joule per second, so an idling CPU consuming 10 watts of energy would take 9290 seconds (or close to 2 hours and 35 minutes) to heat the apartment by one degree kelvin. Do note though that this of course assumes completely unrealistic conditions, for example that the apartment is perfectly thermally insulated against the outside world, so it is of course necessary for there to be no ventilation whatsoever. The building code here demands that the ventilation of private dwellings should change the indoor air at least once every two hours, making the job of that idling CPU a Sisyphean task. So, in conclusion, no, my heatsink isn't inadequately fastened, and the TDP has nothing to do with this at all. I could easily transfer the heat out of the CPU quicker and thereby making it cooler by running the CPU fan faster, but why on earth would I? There's absolutely no reason to. Last edited by TheFluff; 8th December 2017 at 21:43. |
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8th December 2017, 22:10 | #1282 | Link |
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In other words, TDP is just requirement for cooling system.
Note that modern CPUs (and GPUs) could easily exceed TDP index under heavy load (AVX-512 etc.), but integrated current/power meters and forced clock drop won't let them do so.
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9th December 2017, 10:38 | #1283 | Link |
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And yet, you can't explain why a computer left on 24/7/365, using components with high TDP, will raise room ambient temperature by at least 5 degrees. Whereas components with low TDP will not do so, a mild 1 degree bump at most.
Please, Dr. Physics, explain that one.
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9th December 2017, 14:38 | #1284 | Link | |
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One weird trick, discovered by a Doom9 forums poster, lets you violate the laws of thermodynamics. Physicists HATE him! f'in tdp's, how do they work??? |
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9th December 2017, 15:36 | #1285 | Link | |
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As I said, TDP has a very obvious correlation to actual heat output. TDP isn't a measure of it, but it must be closely related. Accumulated TDP can be a good guide to how hot your computer will be, specifically monitoring an increase in ambient temperature in the room. If I can lower room temps by a few degrees, simply by NOT buying an expensive/fancy graphics card, I'm better for it. If watching the TDPs help me make smarter/cooler purchases, then that's what I'll do. So far, that's worked perfectly. Not everybody live in Canada or wherever, where years-round temps are measured in snowfall inches. We must pay close attention to how a computer heats the dwelling. This is a thread about KNLmeansCL, not TDP. I've stripped KNL down to base settings, am getting 10fps now, and have moved on. I suggest you do the same.
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Back in town. If you want my advice, then find me at the DigitalFAQ forum. Glad to assist. Last edited by lordsmurf; 10th December 2017 at 00:07. |
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9th December 2017, 23:44 | #1286 | Link | ||
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I'm not trying to hurt you, I'm not trying to sell you a GPU, I'm not trying to convince you to use KNLMeans, I'm not even trying to dispute your apartment temperature numbers. I only want you to understand why nothing you're saying makes any sense. I will not accept you claiming that you'd prefer to believe in literal magic because you don't understand basic physics. I also really doubt you've made the ambient temperature experiment under controlled conditions, so I really don't think you're getting much mileage out of "thinking for yourself". Quote:
You can plug in a watt meter into the wall socket and then plug the computer into that if you're actually curious about this. They're like 25 bucks on Amazon. You will then notice that your power consumption at idle is a lot more than just the CPU's idling power consumption (because there's other stuff using power in the computer as well, and the PSU is only about 80-90% efficient at converting wall socket AC to low voltage DC), but also that if you actually put your computer under load, power consumption will immediately increase significantly, and there's the difference between idle power and TDP. In practice you can see the computer as an electrical space heater; effectively all of the electrical energy it is using gets turned into thermal energy. I think you're suffering from the misconception that the temperature of the components is interesting for some reason. It's not. It is true that a higher temperature difference between a hot thing and the ambient air increases the rate at which energy is transferred from one to the other, but in this case we're talking about a steady state situation: we're inputting a constant amount of energy per second into the chip, and it's transferring exactly that much energy into the surrounding air per second. If it was transferring less energy out than it was receiving, it would become hotter, because it would be storing more energy. Of course I can't explain the conditions in your apartment with your computer without any details about it. For all I know you might have turned off the CPU power saving features in the BIOS and are always running at full power consumption. Last edited by TheFluff; 9th December 2017 at 23:46. |
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9th December 2017, 23:53 | #1287 | Link | |
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9th December 2017, 23:54 | #1288 | Link | ||
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Sigh. No. I came to the KNLmeansCL threads to talk about the filter, not this BS. I've mostly resolved that encoding speed issue. You're the one that keeps harping on TDP, and my statement of not wanting a graphics card because it add 5 degrees of heat to the room.
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Not where I live. You're assuming too much. Quote:
Huh?
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Back in town. If you want my advice, then find me at the DigitalFAQ forum. Glad to assist. Last edited by lordsmurf; 10th December 2017 at 00:24. |
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10th December 2017, 00:15 | #1290 | Link | |
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One thing I noticed when trying to cut down the KNL settings (for speed) was that adjusting A=2 to A=1 seems to massively cut down on it's effectiveness, yet encoding speed remained almost unchanged. I didn't see why that would happen. Also, the s=1 syntax suggestion from default s=2 did nothing. I'm partially assuming it's related to the 4x calls from the script, or the horrible video where it was used.
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Back in town. If you want my advice, then find me at the DigitalFAQ forum. Glad to assist. Last edited by lordsmurf; 10th December 2017 at 01:15. |
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10th December 2017, 00:38 | #1291 | Link | |||
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lol this forum is barely moderated at all |
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10th December 2017, 11:18 | #1292 | Link |
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Well, it is amusing that kind of discussions, seems you have enough time in your lifes.
BTW if Khanattila (thread owner) want I can delete some off topic posts (or create a new thread about temperature).
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16th December 2017, 16:00 | #1293 | Link |
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I do not care.
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github.com |
16th December 2017, 16:04 | #1294 | Link |
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Either option would probably be appreciated by most users. Just my 2c.
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16th December 2017, 17:28 | #1295 | Link |
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create a new thread about temperature is better in my opinion
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17th December 2017, 18:42 | #1296 | Link |
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Why does KNLMeansCL v1.1 throw this error (i'm using avisynth+MT)
script Code:
video=FFVideoSource("E:\_Video_Samples\mp4\Sony_4K_HDR_Camp.mp4") //420p10 source video=ConvertToYUV444(video) video=KNLMeansCL(video,d=1, a=2, s=4, h=4, device_type="CPU", device_id=0)
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Windows 7 Image Updater - SkyLake\KabyLake\CoffeLake\Ryzen Threadripper Last edited by Atak_Snajpera; 17th December 2017 at 19:07. |
19th December 2017, 18:27 | #1297 | Link |
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Another bug? Possible.
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github.com |
3rd January 2018, 17:56 | #1298 | Link |
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First of all, happy new year
Good, let's get back to release updates. Contrary to what I had planned the v1.1.* branch will have update (bugfixes) because the main changes that I would like to implement are really taking me longer than expected. Let's make a list of known bugs: - clc compile error with OCL 1.2 (fixed); - Broken frame on first request (Bug don't happen when running with d=0, without rclip or inside MP_Pipeline); - Low values of ref clip cause dimmed borders; - Don't work with AMD RX Vega GPU; - Wrong message with YUV444P10 input (fixed)(Atak_Snajpera) - AviSynth+ YV24 native format bug (fixed)(MysteryX)
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github.com Last edited by Khanattila; 29th January 2018 at 17:39. |
29th January 2018, 16:32 | #1299 | Link |
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https://github.com/Khanattila/KNLMea...ses/tag/v1.1.1
Code:
KNLMeansCL v1.1.1 * Added more check of rclip. * Fixed build programm error in some circumstances. * Fixed Avisynth YUV444P10 video format. * Fixed Vapoursynth RGB30 video format. * Fixed clip processing with higher resolution than 4K.
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