Overclocking

Both the Athlon II X2 and the Phenom II X2 managed to overclock to about the same levels. Without any additional core voltage they were able to run at 3.5 - 3.6GHz, with the Athlon II being able to go a bit higher thanks to being free of any L3 cache. With less than 10% additional core voltage I was able to get both chips up to 3.7GHz. The Athlon II X2 250, when overvolted, managed to reliably hit 3.75GHz.

Gary's sample was able to work solid at 4.0GHz while mine would fail at 3.8GHz or above.

Processor Highest Overclock (Stock Voltage) Highest Overclock (Overvolted) % Increase over stock
AMD Phenom II X2 550 BE 3.5GHz 3.7GHz 19%
AMD Athlon II X2 250 3.6GHz 3.75GHz 25%
Intel Pentium E6300 3.40GHz 3.57GHz 28%

 

The Pentium E6300 topped out just under 3.6GHz with ~10% additional voltage. I noticed a strange trend when overclocking the E6300. I set the FSB to 340MHz, which when multiplied with the CPU's 10.5x multiplier should yield 3.57GHz. Yet with no additional voltage, the CPU would hardly ever go above a 10.0x multiplier once in Windows - resulting in a 3.40GHz clock speed:

The chip wasn't throttling due to heat, it simply would not run at 3.57GHz without any additional voltage. As soon as I gave it more voltage or as soon as I disabled EIST, the CPU ran at its correct frequency:


All I did was disable EIST, although increasing the VID also resulted in the same thing

Even with additional voltage however I wasn't able to get the E6300 stable at above 3.57GHz.

Processor x264 Pass 2 Cinebench XCPU Crysis Warhead
AMD Phenom II X2 550 BE @ 3.7GHz 11.0 fps 8224 74.5 fps
AMD Athlon II X2 250 @ 3.75GHz 11.0 fps 7968 75.0 fps
Intel Pentium E6300 @ 3.57GHz 11.7 fps 8096 80.8 fps

 

The Pentium E6300 is actually quite competitive when overclocked and appears to scale very well with additional clock speed. It also helps that AMD's clock speed advantage shrinks once we overclock these chips a bit.

Power Consumption Final Words
POST A COMMENT

56 Comments

View All Comments

  • 7Enigma - Thursday, June 4, 2009 - link

    Hello Anand,

    In the article you seem to imply a tremendous difference in that 2meg to 3meg jump but your single data point doesn't show that conclusion.

    In your example there is a ~9% increase in performance when going from 2 to 3 megs, but there is also a 4.5% increase in clockspeed between the 2 chips. So at best (in this example) you have a 5% difference, which while significant, I would't say it was tremendous.

    Can you comment on whether you did any further tests with identical frequencies?
    Reply
  • FlameDeer - Thursday, June 4, 2009 - link

    Here are some corrections of AnandTech Bench.

    Refer to here:
    http://www.anandtech.com/bench/default.aspx?b=25&a...">Adobe Photoshop CS4 results of few CPUs from AnandTech Bench

    1. AMD Athlon II X2 250 results missing a dot, becoming slower than Intel Atom 230.

    2. Better using "Intel Pentium Dual Core E5300" for E5300 as the name Intel printed on the CPU.

    3. AMD Athlon LE-1620 notes (platform side notes) should be same as AMD Athlon LE-1640.

    Thanks for adding more CPUs for comparison in AnandTech Bench, doing the full test in latest software is really time consuming especially for old CPUs. Take care.
    Reply
  • MadAd - Wednesday, June 3, 2009 - link

    would have liked to see phenom (non II) compared, especially the low end x3s, users may be thinking of upgrading from those about now Reply
  • FlameDeer - Thursday, June 4, 2009 - link

    You can always conveniently & interactively comparing them here.
    http://www.anandtech.com/bench/">AnandTech Bench
    Reply
  • Elementalism - Wednesday, June 3, 2009 - link

    I never had much luck running Cool n Quiet when I used to run AMD processors. Even in games the CPU was put into a low clock mode running at half speed. Sounds like a buggy implementation to this day.

    And I cant say in my experience it was the Mother Boards fault either. I enabled Cool and Quiet in the bios and nothing happened. It wasnt until I installed the Cool n Quiet driver all hell broke loose.
    Reply
  • mino - Wednesday, June 3, 2009 - link

    However one has to keep in mind the bug comes from Redmond.
    The Win 5.x scheduler is a piece of garbage and it allways was. It is just that it shows with different symptoms:
    1 CPU core => crappy multi-tasking on heavy loads
    2+ CPU cores => unable to get a grasp that power management not a thing of the future ...

    A no, being from 2000 is no excuse, proper OS scheduler were there 30yrs ago.
    Had MS decided to do so, their Win 5.x schedules would be a proper one from the start.

    As for AMD, it is a price one pays for being ahead of the market.

    Remember, it took Intel 5yrs (2003-2008) to get comparable power management capabilities as AMD with Nehalem.
    Reply
  • mino - Wednesday, June 3, 2009 - link

    sorry for the spelling mess.. Reply
  • Hrel - Wednesday, June 3, 2009 - link

    YAY 3D max, also that E7500 is beating the crap out of everything but AMD's top of the line. That really solitifies in my mind that picking the E8400 6 months ago for my friends gaming computer was the right choice. Stupid AMD, I REALLY want them to be competitive again so Intel is FORCED to stop overcharging for EVERYTHING. Reply
  • mmpalmeira - Wednesday, June 3, 2009 - link

    Did you try to overclock the uncore of the AMD's CPUs? Reply
  • calyth - Tuesday, June 2, 2009 - link

    Just like that article that you linked to with the name CnQ bug, I don't believe that a hardware manufacturer creates a bug if the OS scheduler can't seem to do the sensible thing and not bounce threads around. Although various factors in the AMD chips make the problem worse, bouncing threads across different cores on an Intel chip also has a bit of impact, since L1 and the L2 shouldn't be shared across cores on the i7 platform.

    So please, stop calling it a bug. The bug lies in Windows, not the chips.
    Reply

Log in

Don't have an account? Sign up now