Wednesday, September 8, 2010

Development of Intel processors clock speed per watt

Today it's more difficult to count performance per watt of a processor because of wide variety of integrated chips in different processor families. From all Intel's processor families I'd like to pick up just a couple to show what I mean:
Intel® Atom™ Processor Z500 was introduced at Q2'08. It runs with max TDP of 0,65W with a clock speed of 800MHz. It's a single core processor without any extras (EIST support is included for even less power consumption). Performance against power consumption is tremendous 1231 GHz/Watt with direct calculation.
Intel® Core™ i7 Mobile Processor i7-660UE is a modern slim CPU developed for ultra thin products. Of course it can be the heart of any system builds, and I'm considering it for my recommendation list of power efficient CPU's for HTPC. It was introduced at Q3'10 (just a while ago) and it represents a full featured multimedia CPU. Same direct calculation gives to it 267 GHz/Watt (to reach that I've used turbo speed of 2,4GHz, which is additionally doubled because of two cores). True performance per watt, however, is a way bigger than what Atom Z500 has, since this 18W max TDP processor carries an army of chips along . There's memory handling, integrated HD-graphics etc... read more from Intel's product page.

Following chart show only a simple max GHz/max TDP, but since the chart includes 550 processors for both mobile devices, desktop pc's and servers, it still tells us something about the speed of development towards energy efficient performance. Curve still lies a lot due that the latest models include more and better chips - those chips consume power that doesn't show up in clock speed. Counting that along - the development is actually even faster.

Simple development of performance per watt of all Intel processors manufactured between 2002-2010(Q3). Click image for larger view.
- Red dots are max TDP values.
- Grey dots
are a calculated value of max GHz/max TDP. In the calculations amount of cores has been used as a multiplier for clock speed. If a processor has TBT the clock speed is calculated with max Turbo speed suggested by Intel.
- All information for calculations are from Intel's product page. Charts is cutted to show max 250 GHz/W, there are several processors that gives more. Those processors are, however, included in the curves.

Conclusion: Variety of max TDP has always been wide and seems to go on getting wider in the future too. Selecting a suitable, most energy efficient processor for anyone's personal needs get's difficult because of this, but on the other hand it's possible to find just the right one with some study and maybe professional help. I hope that people think about their true needs in advance, in that way you don't buy a computer which consumes power which isn't used for anything. Pure GHz maximum for a single core was reached years ago, but more and more cores are been used together for more calculation power. This shows in ongoing development of GHz/Watt but please do not stare to that nomber too much. In a single processor it's a mostly useless number telling only simple calculation speed of the processor, and today computers are used for totally different jobs than for computing. With larger amount of data together it tell's us that maximum lvl lies far away in the future, so we could keep on changing our processors for better and better in the following years too.

Opinion: We must think what is enough for us. A football game may reach more and more realistic level on your screen, but when does it reach the level of reality what you get when you go to a real football field? I also remember what boom Tetris was just few years ago - and you could play it with 3bit graphics (8 colours) and 20x10 resolution. I must admit that watching movies with HD quality is something I value. Is it going to be even more enjoyable with 3D and 19800 x 10800 pixels? Does the reality level reach what we see in a theater play with real people on stage?

max TDP (maximum Thermal Desing Power) is a maximum amount of wattage that processor can handle. Never reached in normal use of computers.
GHz = Ticking speed for each core in a processor. 1 GHz = 1 000 000 000 calculations in one second.
TBT = Intel Turbo Boos Technology

If you are interested of your own processors performance, or if you're looking for CPU for your needs, leave a comment. If this subject shows more interest in general, I might calculate some more nice curves within certain TDP levels and same amount of chips included.





  1. iám looking for a new processor to my mmPC. what would you recommend? low power low noise

  2. Thanks, if I got this roight, by mmPC you mean multimedia PC. So what kind of multimedia performance you hope to have? (video quality HD 1080p or 720p? Do you play modern games?)

  3. I forgot to say i got asus crossfire to all gaming and HTPC ... i look asus E6X58 what is this for?

  4. Do you mean Asus P6X58? It's a nice looking MB but check this too: Gigabyte GA-X58A-UD3R.

    Silent (passively cooled) processors are probably out of question for your purposes. You might have some price level on your mind, but check out these two (for either MB):

    For quite energy efficient build:
    - Intel® Core™ i7 Mobile Processor i7-840QM

    For lower budget, performance with reasonable noise level and power consumption:
    - Intel® Core™ i7 Desktop Processor i7-870S
    - Bigger heatsink to replace the original (maximum size depends on your case, check at least Scythe Yasya with 12cm PWM controlled low noise fan on it)