Intel Centrino Overclocking Guide Posted!

Discussion in 'Reviews & Articles' started by Dashken, Jan 30, 2005.

  1. Pug

    Pug Newbie


    IMPORTANT -- FSB and MEMORY are not the same

    Your FSB is SUPPOSED to be at 100 Mhz.. that is perfectly all right and just as it shoult be

    Your Memory should be at 166 Mhz...

  2. yakrider

    yakrider Newbie

    Hey, Pug thanks for all the info. My laptop makes almost no noise except for the hard drive (the fan almost never runs) however, I was interested in RMClock so that I could economize on my battery when I'm moving around with my laptop.

    Sorry that I'm such a newbie, but I cant seem to underclock my processor any more with that. The only range available seems to be from 6x FID to 16x (which my 1.6G centrino processor does automatically), and the VID range from .7 to 1.484 V which is the normal range too. There were more .reg file, but they didnt seem to help much either.

    Also, I have Radeon mobility 9600 but havent overclocked it. I would appreciate any suggestions as to the best way to go about doing it and recommendations on what values not to cross. I dont really use my laptop for much gaming though.

    Thanks in advance
  3. Pug

    Pug Newbie


    First of all...

    If you don't use it for gaming ...don't overclock ... neither CPU nor your Ati..

    RMClock allows you, to use a lower Vcore - thus the CPU does not get as hot as it would at default voltage.
    For Example..

    A Pentium M 1.5 Ghz usually needs about (this differs!!) 1.454 V for the maximum speed. At 600 Mhz, it only needs 0.989 V.

    You can use RmClock to do the autostepping (switching from 600 - 1.5 Ghz) for you. Moreover you can TRY out lowering the Voltage.
    Be very careful - a voltage that is too low possibly lets your System freeze. You have to restart - but thats it..

    I recommend to you to download a tool like prime , with which you can start a "torture test" - Cpu is 100% in use and calculates known soon as an error occurs, it stops.

    Run the torture test ...To be sure that your system is stable you need to run it for AT LEAST 60 minutes..while doing that, you can lower your voltage step by step.

    Use rmclock to set your cpu to MAXIMUM speed ("P-state Profile: maximum")
    start torture test
    lower your Vcore.. I can lower it sth like 1.19 V...some get even under 1.0 V..which is just great.. Then your fan may not even be used while playing doom3 or comparable...

    As soon as prime reports an error and stops the test - go back up one or two steps in the voltage.

    The do the same with P-stat Profile minimum... Here it should be possible to get as low as 0.8 V or even less.

    After finding your Voltage settings... choose them and put a link to rmclock into your startup folder.

    Thats it.
    Sounds difficult - but in fact its easy...!!

    Only try this if you are sure what you are doing.
    Keep in mind that you are meddling with expensive hardware. IMHO undervolting is NOTHING compared to overclocking in regard of a possibility of permanently damaging your system...,, - but nevertheless.. be careful.

    Thats about it.Hope it helps..
    Excuse my sometimes disappointing english.

  4. Pug: I should have written memory instead of FSB - I know the FSB is supposed to run at 100 Mhz and the memory at 166 Mhz - a 3:5 divider, but CPU-z reports that my FSB runs at 100 Mhz and my memory runs at 100 Mhz too - a 1:1 divider
  5. Pug

    Pug Newbie


    Very strange indeed that your M6N is using a 1:1 divider.

    As well it is very interesting to hear, though. For hardcore overclockers who try to use a FSB of 133 Mhz, a 1:1 divider would not be THAT bad - the memory, in our notebooks probabably PC333 DDR-Ram, would only use 133 Mhz...

    I don't know how to change the divider on the M6N - and I doubt that we'll find a way how to do that....

    But how did you? :rolleyes: hehe... How long do you have your notebook. I cannot believe that it was sold like that.... :think:

    This gives me hope...

  6. I like that you look in it that way :D

    I really don't remember how I have been able to change the divider... Before I read the german thread in the one of the links you gave me, I tried to "experiment" with some different clock generators... but I never noticed anything about the divider being changed.
  7. I have had my notebook for about a year, and I haven't tried overclocking it before now.
  8. Pug

    Pug Newbie

    You could try hard-resetting your nb. On the back there is a really small hole. punch it for a couple of seconds.. maybe the divider is set to the original again....
  9. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Hello yakrider,

    As mentioned in the guide, ClockGen can misread AGP, PCI bus speeds. Do NOT trust those values.

    By default, your AGP bus should be 66MHz and the PCI bus is at 33MHz. Assume that they are running at those speeds, no matter what ClockGen says.

    To double-check that overclocking the FSB also overclocks the AGP and PCI bus, you can confirm by testing the burst transfer rate of the hard disk. Again, this has been covered in the guide.

    So, if your motherboard does not lock the PCI bus (as we would expect), then overclocking the FSB by 10% will also overclock both AGP and PCI bus by 10%.

    ClockGen will detect the clockspeed the processor was set to run at. The Pentium M will automatically clock down itself according to workload but that's independent of the clock generator.

    Don't let the false PCI and AGP bus speeds confuse you... ;)
  10. Pug: I tried pushing a small button in the bottom of my laptop. It restarted after I released the push, but the divider unfortunately didn't reset :-/
  11. Lol, I just downloaded the newest version of CPU-Z (1.27), and it shows me that my memory is running at 166 Mhz at a 3:5 divider.

    So I guess I "unfortunately" haven't found the magic way to change the divider in my notebook :)
  12. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Honestly, I don't think it's possible to change the divider. :think:
  13. highlandsun

    highlandsun Newbie

    Changing memory divider

    Use PCREdit. I have a writeup on my web site showing how to change
    Centrino Memory Timings

    From the i855PM data sheet spec update, section 3.7.41, there are 3 dividers, set in bits 11:10 of the 16 bit register at address C6-C7h. 00 = 100MHz (DDR200), 01 = 166MHz (DDR333), 10 = 133MHz (DDR266)
  14. Pug

    Pug Newbie


    This is great news!! :thumb: Thank you very much... i'll try slowing the Memory to 133 Mhz and then raising the FSB to 133 Mhz -> thus the memory should be back at 166 Mhz (default) AND the divider for PCI/AGP COULD change to the one used in the new sonoma chipset series (thus agp & PCI @ defaults as well)....
    That would be too good to be true.

    Thanks again for your info..


  15. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Interesting write-up! :thumb:

    I'll test it out myself as soon as I can. :thumb:
  16. Pug

    Pug Newbie


    On the right side of the program window the "0""1" setting is described as standing for 166 (=333) Mhz, exactly as you said...
    I tried setting the Memory Speed to 133 (=266) Mhz by changing the two bits you described ( "0" and "1" ) to "1" and "0".

    Freeze.. :(

    Too bad...but I won't give up hope yet..
    Presumeably I've made a mistake..

  17. highlandsun

    highlandsun Newbie

    Unfortunately my Centrino laptop (Asus M6Ne) is at Asus being repaired right now (fried battery charging circuit) so I can't verify the settings. But I'll check in again when I get it back.

    Also, another point of interest - section 5.7 of the datasheet says
    If you google for CK408 clock, the Cypress CY28346 is only one of many matches that comes up. It should be possible to find specs for many others, and they all ought to be compatible to a large degree since Intel has specified this feature.
  18. Cobalto

    Cobalto Newbie

    Same problem here !

    My Dell Latitude X30 (Dothan 1,4 LV) goes up to 1.860 Mhz (tested using Prime95 for hours...).
    That's great, but I can't have te settings applied automatically because I am experiencing the same problem you are describing, no matter what I do.
    Please, can somebody help ?
    Thanks in advance.

  19. Cobalto

    Cobalto Newbie

    Problems with ClockGen and Centrino: can't read savefile and more

    Hi everybody ! I post this message, that I have already sent to Adrian in private, for public discussion. First, I thank Adrian for all the useful advice that he provides on his website and forums.
    I have obtained exeptional results with my DELL Latitude X30 (P-M 1,4 Ghz LV -> 1,860 tested with Prime95 - could be more if I could get rid of the integrated 128 MB...) but I can't make them permanent ! There is no way that I can make clockgen read the savefile.
    Whatever I do I always receive the message: 'Error reading param file'. The ClockGen version that I'm using is for the CY-28346 chip.
    I have seen that other users have similar problems. I'm wondering if the matter is tied to some kind of user switch / protection of WXP SP2 + Norton AV 2005.

    BTW, after overclocking the system won't shut automatically. I have to press the power switch at the end of the termination sequence...

    Thanks in advance for any help that you could provide.

    Kind regards,

  20. Pug

    Pug Newbie


    Great results. How did you achieve them?

    Raising the FSB to 133 Mhz? Don't u get problems with your Sound and Harddisk due to the hardcore overclock to your PCI and AGP speed?

    I am using clockgen now and then...never tried autostarting..
    But i will try and report...


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