markw Posted August 5, 2014 Share Posted August 5, 2014 Not finding any problems with the forums today , I thought I would ask a question instead. Looking around at differing computers with multiple cores, I notice that as the number of cores goes up the speed of each goes down.Can anyone here offer an insight into why this should be? Quote Link to comment Share on other sites More sharing options...
Fuchur Posted August 5, 2014 Share Posted August 5, 2014 in general it has to do with leakage power and heat developement especially if they are on the same chipsize. 4 cores produce more heat than 1 core. like that with the same cooling and powerconsumption u can use one core at lets say 5 ghz or 4 at 3 ghz. actually the difference is not that high but it is one of the reasons. modern turbo modes take advantage of that and overclock one core when the others are not used and visversa. Quote Link to comment Share on other sites More sharing options...
markw Posted August 5, 2014 Author Share Posted August 5, 2014 Thanks Gerald, I know I'm swimming out of my depth here! I'm not sure what you mean by "leakage power"? but I get what you mean about heat output.Though in and of itself the heat problem can be solved by more efficient cooling. Whilst this is always going to be a problem in a laptop, for a tower system space for sufficient cooling is only an issue if you want it to be.It seems to me that the heat issue can't be the deciding factor. Quote Link to comment Share on other sites More sharing options...
Fuchur Posted August 5, 2014 Share Posted August 5, 2014 Had a look in a dictenary: Leakage power = leakage flow / leakage current,,, The questioni s, where we are at... is the CPU already running at a level that is close to its top heat or not? Are we already using the best airflow we can without a massive cost increase? Do we need to go with liquid helium or at least water or oil cooling to make it much better? Cooling is really not a small issue at all because it really is not only about the temperature you get from the CPU as a whole but what is with certain parts of it, especially with transistors which are only a few nm in size? And keep in mind: you can overclock your CPU to a certain amount which is easier when the heat is down (=better cooling).... in general you try to use the safty gap they tried to include to run the system flawlessly... and since no CPU is exactly like another even from the same production day, this results in CPUs from the same stepping which behave much better than others in terms of overclocking... But there is much more about it of course... powervconsumption, leakage flow, structure size, main board, what kind of RAM and Cache and how is it connected to the cores? Long story short: Higher clockrates are easier to obtain with less cores... this is in general the single-core speed of a CPU vs the n-core speed of the cpu... For instance: Intel processors tend to be quite a bit faster concerning single-core-speed. AMD APU/CPU are at least as fast or faster when using n-cores because they include more cores to the same die-size... But this is more of a design issue / decission than anything else and is not too much about the topic... Quote Link to comment Share on other sites More sharing options...
markw Posted August 6, 2014 Author Share Posted August 6, 2014 Thanks again Gerald, I new the answer would be more complex than I was hoping for! It all dose make trying to decide what configuration of computer to have quite tricky. Fewer faster cores may be good for one app but having more, even if slower, may be better for another app. Quote Link to comment Share on other sites More sharing options...
Fuchur Posted August 6, 2014 Share Posted August 6, 2014 yes exactly that. it is hard to decide about that. do you use multiple programs at the same time? use a multicore system. do you use software that utilizes more than one core? or do you use software that does not? and is a faster single core cpu faster than multicore if run one after another task? (in general the answer is no... but not always) in the end: if u want it for rendering: get a multicore system. for an laptop a dualcore may be better since it runs faster but consumes less power... Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted August 6, 2014 Hash Fellow Share Posted August 6, 2014 How much difference in speed are talking about between the fast and not-as-fast? Quote Link to comment Share on other sites More sharing options...
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