Power Consumption

Idle Power Consumption

Without power gating the Athlon II X4 draws as little power as possible, noticeably less than any of AMD's other multi-core CPUs. Our X4 620 sample was a bit more power hungry than our 630.

Load Power Consumption - x264 HD Bench Pass 2

Even under load the power consumption story is a good one. Given the position of our Q8400 sample here we'd say that the Q8200 would probably use a bit less power, but the price differential should more than make up for it.

Overclocking

As I mentioned at the start of this article I managed to hit 3.25GHz on the Athlon II X4 620 without any additional voltage using the retail AMD cooler:

I could hit 260MHz x 13.0 for 3.38GHz by upping the voltage, but the gain wasn't worth the additional power usage. Anything higher wasn't possible without more exotic cooling or much more voltage. The performance improved handily at 3.25GHz:

Processor Adobe Photoshop CS4 x264 2nd pass Left 4 Dead
AMD Athlon II X4 620 (2.6GHz) 27.5 seconds 15.4 fps 93.2 fps
AMD Athlon II X4 620 @ 3.25GHz 23.2 seconds 18.9 fps 102.9 fps
AMD Phenom II X4 955 (3.2GHz) 22.3 seconds 19.1 fps 121.4 fps
Intel Core 2 Quad Q8400 21.8 seconds 17.9 fps 105.6 fps

 

At 3.25GHz the Athlon II X4 ends up faster than the even more expensive Q8400in some cases, and gets much closer in others. In applications where the large L3 cache isn't missed, the overclocked Athlon II can end up being a poor man's Phenom II X4 955. But looking at the Left 4 Dead performance, there's no such thing as a free lunch - the overclocked Athlon II isn't quite that good.

Gaming Performance Final Words
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  • thezorro - Wednesday, September 16, 2009 - link

    remember that the lynnfield core i7 750 has turbo overclocking enabled so is overclocked to 3.2 ghz, which is 600 mhz overclocking, while amd processors are running at stock speed
    Is unfair to present the results this way, turbo is overclocking.
  • Wivvix - Thursday, September 17, 2009 - link

    Sorry but your logic fails. It is a feature of the i7 750, that it runs at slower speeds when idle, as to when the processor is under load.

    In the same way, fan speed RPM is automatically regulated depending on whether the process is idle or under load.

    The maximum clock speed of an i7 750 is 3.2gh. The user doesn't have to change or do anything. This is not overclocking in the sense you purport, and is not unfair. That is the maximum clock speed of the processor out of the box. End of story.
  • kagenokurei - Wednesday, September 16, 2009 - link

    im sorry, but i have to defend thezorro at least this time..

    overclocking's basic principle is to increase CPU speeds..but if u guys look into it, what u increase is the core clock(GHz,MHz,etc) beyond the factory released specs..voltage increases and other tweaks are only done to make the overclock stable..

    now,in this light,i also find it quite unfair to compare the single threaded performance of the i7s with the PII X4s..simply because the i7s can run its single core at a higher clock when the others are idle..therefore,overclocking at least THAT core..w/c of course, the PII X4s are unable to do..

    i agree that the Turbo mode is a good feature, and AMD should have something like it on their CPUs..until then, the Turbo mode is kind of an unfair advantage in benchmarking single threaded performance..
  • jonup - Wednesday, September 16, 2009 - link

    Well the PII 965 is an overclocked to 3.4GHz, which is 600MHz overclocking of 920. It's unfair to present the results this way. The 965BE is so obviously OCed because it uses tons more power than the 920.
  • fitten - Wednesday, September 16, 2009 - link

    Bzzzt... wrong... when will you fanbois give this up? It's the normal and default behavior of the thing. You can do the academic discussion all you want but normal operation of the chips has Turbo enabled. To test any other way is to test a non-standard, non-default operating mode. You might as well test with the caches disabled or one or more cores disabled since those are all non-standard, non-default operating modes as well.
  • maxxcool - Wednesday, September 16, 2009 - link

    ++ ding!
  • Archangel59 - Wednesday, September 16, 2009 - link

    I can see both sides of this where Turbo could be considered altering the "normal" operation and also where turbo could be considered just the way it works.

    Doesnt bother me either way that this is put in the article, still good news from AMD.

    However, since the turbo mode could be considered a supplied feature of the chip... couldnt the use of AMD Overdrive be considered a supplied feature of the newer chips? Even if it couldnt, I'd still love to see an article comparing the turbo mode to a well set up AMD Overdrive profile.
  • Lunyone - Wednesday, September 16, 2009 - link

    So what your saying is that the test are fair because AMD doesn't have this "turbo" mode, so all of the benchmarks are created equal?? So if the benchmarks had set up the 955/965 to 3.2 gHz (with unlocked multiplier) than you would have a favorable review??
  • Lunyone - Wednesday, September 16, 2009 - link

    Crap! I meant to say "aren't fair" in a couple of lines in my response :(
  • SlyNine - Wednesday, September 16, 2009 - link

    Turbo mode is not overclocking. Overclocking is clocking OVER factor speeds.

    If the CPU can increase the speed as a factory set speed. THAT IS NOT OVERCLOCKING, so get over it.

    On the other hand. Go AMD. I'm still awaiting the big Core I7 killer. comon AMD you can do it.

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