Updated: Tuning Cool'n'Quiet: Maximize Power And Performance

Test System

Test System Configuration
CPU

AMD Athlon X2 7750 (2.7 GHz, 3MB cache)
AMD Athlon X2 7850 (2.8 GHz, 3MB cache)
AMD Athlon II X2 250 (3 GHz, 2MB cache)
AMD Phenom II X3 710 (2.6 GHz, 8MB cache)
AMD Phenom II X4 945 (3 GHz, 8MB cache)
AMD Phenom II X4 955 (3.2 GHz, 8MB cache)

Motherboard

AMD 790GX:

Biostar TA790GX 128M
Gigabyte GA-MA790GP-DS4H
Gigabyte GA-MA790GP-UD4H
Biostar TA790GX A3+

RAM
Kingston KHX8500D2K2/2G  PC1066 (4GB) at DDR2-800 CAS 5-5-5-16
Team Elite TED32048333HC9D PC1333 (8GB) at DDR3-1066 CAS 9-9-9-24
Graphics Card
ATI Radeon HD 3300 (AMD 790GX), 500 MHz GPU
Hard Drive
Western Digital Green Power 1TB WD10EACS, 16MB cache, SATA 3.0 Gb/s
Sound
Onboard Sound, Realtek ALC880
Networking
Onboard Gigabit Ethernet, Realtek RTC8111C, 1 Gb/s
Power Supply
PC Power & Cooling Silencer 750W ATX12V v.2.2, EPS 12V CrossFire Edition
Enermax Tomahawk 405W ATX12V
CPU Cooler
Thermalright Ultra Extreme 120, Noctua NF-P12 120 mm fan
Fans
2 x Noctua NF-P12 120 mm fan (not including CPU fan)
Software
Operating System
Windows Vista Home Edition 32 bit SP1
Graphics
AMD Catalyst 9.5
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48 comments
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    Top Comments
  • cyberkuberiah
    On the behalf of all readers , Welcome , and so to say , Hi! , Arnawa Widagda :)
    13
  • DrgnRebrn
    Nice article! I'm curious to know if the "e" CPUs can be affected in the same way, such as the Phenom II X3 705e. I have chosen this CPU for a HTPC build because of it's already low 65W TDP. Also, what are the effect to power usage when using ACC features & enabling dormant cores?
    12
  • Anonymous
    Very good article! Undervolting it's a great tweak to make and most of the people don't even know that it is possible as well as overvolting, getting a power efficient processor for no money! Thanks tom's for caring about this matter.
    12
  • Other Comments
  • DrgnRebrn
    Nice article! I'm curious to know if the "e" CPUs can be affected in the same way, such as the Phenom II X3 705e. I have chosen this CPU for a HTPC build because of it's already low 65W TDP. Also, what are the effect to power usage when using ACC features & enabling dormant cores?
    12
  • cyberkuberiah
    On the behalf of all readers , Welcome , and so to say , Hi! , Arnawa Widagda :)
    13
  • Inf3rnal
    I'd like to see same article about Intel i5/i7 power setting tweaking.
    3
  • razor512
    did any of these changes negatively effect performance?
    5
  • Anonymous
    Very good article! Undervolting it's a great tweak to make and most of the people don't even know that it is possible as well as overvolting, getting a power efficient processor for no money! Thanks tom's for caring about this matter.
    12
  • nukemaster
    My old A64 3200+ is about to get this treatment
    1
  • autoimmune
    Inf3rnalI'd like to see same article about Intel i5/i7 power setting tweaking.
    O my GOD i bet the writers at Toms Hardware had not thought of that, and are not currently in the process of writing that article!
    -8
  • Anonymous
    i love you guys. i have just the system that i am using as HTPC. i was wondering about ways to reduce the power usage as i dont use it for hardcore gaming or any other cpu intensive jobs. all i use it for watching blurays and tv and other movies and songs. i have an ASROCK 790gxh 128M mobo. and 1thlon x2 7750 kuma, that i bought from newegg for $59 (darn steal for the performance it gives. the machine has almost zero latency for any operation)
    0
  • Jerky_san
    Anyone know where to get k10stat?
    -2
  • cushgod
    Google it Jerky
    0
  • enzo matrix
    Great article. I've been undervolting my Athlon 64 x2 in my laptop with K10stat for the past few months. The tx2500 models get hot. On load I went from a maximum of 90C to a maximum of 75-80C. Haha. no longer worried. Plus my fan doesn't go on maximum unless under full load anymore.
    0
  • mende21
    It's great to see an in-depth article about k10stat. I discovered that program a couple of months ago and use it to underclock and overclock my 955. I hated disabling cool n quiet to overclock my processor and k10stat works great. I have it set to underclock to 400mhz at idle and overclock to 3.8ghz under load. After reading this, I think I can lower the voltages a little.
    1
  • fsjis1
    It may be that AMD is making a purely dual core kuma and I am not aware of it, but I am fairly certain that the kuma series is actually a "phenom I" with two cores disabled, hence the L3 cache. I just did a google search and found people who have unlocked the extra cores on the athlon X2 7750 kuma. Nice article by the way I have been thinking about doing something like this to my PC's.
    2
  • arnawa_widagda
    First of all, thanks for all the comments and feedback.

    All Cool'n'Quiet 2.0 processors should work with K10Stat, so you should be able to use K10Stat with the Energy Efficient series.

    For those unfamiliar with K10Stat, here are some additional switches/options (insert these via the properties menu of your K10Stat shortcut).

    -lp:# - load profile# and write to MSR (activates a certain profile).
    -nw - Start K10stat with NoWindow (don't display window).
    -ClkCtrl:#(0-4) - Enable Clock Control (activates clock/core control).
    0:No Control
    1:UnGanged.
    2:Ganged (Load of Highest core).
    3:Ganged (Average load of all cores).
    4:Ganged (Load of Lowest core).
    -StayOnTray - puts K10Stat on the system tray. Use this option with “-nw” to keep K10Stat running. Very useful if you use sleep/hibernate.

    To those interested in Core i7/Core i5, a similar article is in the pipeline. We wanted to include the 32 nm refresh too, in addition to Core2Duo and Core2Quads, so we have to wait until (final) samples are out.

    About performance, performance differences and actual power consumption will be in the 2nd part - you'll see it soon. You might be (pleasantly) surprised.

    Thanks. Off to some more GPGPU testing.
    9
  • Jerky_san
    CushgodGoogle it Jerky


    People that say that tend to be fairly annoying.. Anyways I finally found a mediafire link.. all the geocities and rapid share links are dead..

    http://www.mediafire.com/?dywh3zhmk41
    -2
  • AMDnoob
    can somebody tell me why my C'n'Q no longer functions? Go to my profile and look for the forum thread i started, it's all explained there.
    -5
  • nukemaster
    Is there a K8 equivalent app?
    0
  • Anonymous
    I'm writing this on a 7750 (stepping 3) with a Foxconn A7GM-S motherboard, and CPU-Z reports 1.024V with Cool & Quiet on, and 1.312V at full speed. I'm not sure why you are observing different behavior.
    -1
  • wira020
    Nice article.. but it is a verrrrrrry lonnnnnnnnnnnng read.... hope you guys can simplify the article a bit... but nice research indeed... xD.. i'm just one of those lazy people that have a hard time reading thousands of words per page.. hehe...
    -4