PLL Pinmod Overclocking Methods and Examples

Discussion in 'Hardware Components and Aftermarket Upgrades' started by moral hazard, Jun 24, 2009.

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  1. tqbinh

    tqbinh Notebook Enthusiast

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    I successfully overclock / overvolt/ undervolt my Lenovo T61 without soldering/cracking motherboard. Below is the short report.

    Overclock:
    Problem: Intel chipset lock the CPU at lowest multiplier (6x) if it is forced to work at frequency higher than designed. In the case of 965 chipset the limit is 800MHz. For IBM / Lenovo laptops, the BIOS also prevents the computer to boot up.
    Research: The chipset determines working frequency using BSEL pins (CFG0-CFG2 on Picture 4 for 965 chipset). Fortunately, for Lenovo T61 there are three 1K resistor between BSEL pins of the chipset and BSEL pins of the clock generator (Resistors 1024-1026 on Picture 4). Therefore, we can cheat the chipset by putting different voltages to it’s BSEL and clock generator BSEL pins.
    Solution: Pull-up BSEL pin of the Chipset to VCC line and pull-down BSEL pin of the Clock generator to ground. For overclocking FSB from 200Mhz to 266Mhz, we need to mod BSEL1 (see Picture 4).
    Practice: On Picture 3 the B1 pinmod was made to pull-up BSEL1 pin of the Chipset to VCC1R05. Connection was made by ATA-66 cable to the two holes on the motherboard (in order to keep warranty). Later, if the overclock is successful, you can (permanently) solder B1A mod between R1025 resistor and near by big capacitor.
    On Picture 8 the B2 pinmod was made to pull-down BSEL1 pin of the Clock generator to the Ground (there is a line connected the hole on Pic. 8 to pin 7 (BSEL1) of the clock generator). For switchable overclock, you can make a switch here (I keep the switch in the unused modem jack).

    Extra: The IDA problem. When IDA is activated, the Penryn CPU gets very high multiplier /frequency, e.g. 14x/3.724Ghz @ 266Mhz FSB for T9500 CPU. To make overclock stable, you need to disable IDA. Following advice of one Chinese guy on 51nb forum, I disabled Speed Step in BIOS (Config -> Power Option -> Intel Enhanced Speed Step -> Disable). However, in my observation, this not fully disables Speed step, because in Windows 7 my overclocked T9300 (at 3.2Ghz) falled in Prime Blend Test after 10-15 min during transition between test modes, for example between 1024K and 8K, while it is rock stable in Prime Small FFT test (harder for CPU/FPU). The Min and Max CPU are set to 100% in Power profile of Windows 7. The problem is less frequent on Windows XP.

    --------------------------

    Overvolt:
    Problem: A regular method is to connect some VID pins of CPU to VSS pin, for example VID2 to VSS to overvolt by 0.05v. However, this can disable some voltage in the VID table, what is not good for me because I also want to undervolt by moding VID4 (see below).
    Research: In the feedback circuit of VCC_CPU_Core regulator ADP3207 IC (Picture 5) there is a 1.65K R569 resistor. We can design a simple voltage divider here.
    Solution: Put a 20K resistor between right side of R569 and VSS_SENSE line. Thus, we make a 92% voltage divider before VCC_SENSE go to Feedback pin of ADP3207. The voltage will increase by 8% for all values in the VID voltage table.
    Practice: See B4 mod on Picture 7. It is very important to make reliable contact to the holes (I used a acurately filed leg of a 0.5W resistor for this purpose).

    -------------

    Undervolt:
    Problem: You can use VID to VCC mod (in my case VID4 to VCC mod to undervolt by 0.2v, from lowest 0.925v to 0.725v). However, for Core Duo CPU the VCC pins are located far from VID pins -> not easy to make mod, unlike VID to VSS mod. Moreover, when make VID4 to VCC mod, the computer may hang up because in low power states it requires a voltage somewhere between 0.5 and 0.7v, and due to the mod, the voltage can be as low as 0.3-0.5v.
    Solution: Use external holes on motherboard to make the mod. In parallel, make a overvolt as described above.
    Practice: see mod B4 on Picture 6.

    -----------------

    Results:
    T9300 overclocked to 266x12=3.2Ghz@1.20v. Do SuperPI 1M less than 15 sec. See attached picture. Temperature in Prime Small FFT is about 82-85 deg (ambient temperature 18 deg Celsius).
    However, as it was described above, the T9300 is not very stable with Prime Blend Test (due to IDA ?), so I have to make VID2 to VSS mod to force it to run at 1.375v (with 8% overvolt) in IDA mode and 1.27v at 3.2Ghz (because after mod, the voltages between 1.20 and 1.27v are not available). Too hot for me. So I replaced it by a T8300, and it is fully stable at 1.20v.

    Therefore, my current system is:
    Lenovo T61 frankenpad in T60p UXGA IPS chasis, T8300@3.2Ghz@1.20v, undervolted by VID4 to VSS mod and overvolted by 8% by feedback circuit mod. At lowest multiplier (1.6Ghz), it works at 0.775v!

    -------------

    PS. Pic1 and Pic2 is overview of mods.
    The forum allows only 6 attachment. So see the rest of pictures in the next post.
     

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  2. tqbinh

    tqbinh Notebook Enthusiast

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    T61 OC: The rest of pictures.
     

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  3. miro_gt

    miro_gt Notebook Deity

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    ^ what a wonderful work from Binh :D ... first to manage to OC the T61 by increasing the bus speed while tricking the chipset, hehe.

    for OC purposes you'd be better off disabling IDA from the BIOS, as it requires much bigger voltage step increase (~5x times) than what it is needed between regular multipliers. Thus at high frequency the chip would heat up by a lot more.

    ---

    I would like to add the performance increase note here, as I've calculated it based on the CPU performance charts from here:

    PassMark CPU Benchmarks - High Mid Range CPU's

    T8300 - stock score 1,489 => OC to 3.2GHz is 33.33% increase => estimated score 1,985

    T9500 - stock score 1,839 => Dual IDA to 2.8GHz is 7.7% increase => estimated score 1,980

    X9000 at 3.2 GHz smokes both obviously at estimated score of 2,262, which is 23% over stock T9500, with the expected temperature increase over both of the above of course, thus would be the practical limit for performance enthusiasts. Temperatures could go above 90 deg C here so watch out.

    - note 3.2Ghz clock requires about 1.2 Volts to operate. T8300 having 3Mb of cache would not heat up as much as X9000 (no IDA) with its 6Mb cache at the same speed and voltage. It seems that T8300 at 3.2GHz at ~1.2V would heat a little over T9500 at Dial IDA at 2.8GHz at below 1.1V while producing the same performance. My T9500 at Dual IDA at 1.0750V is stable and tops at about 80 deg C with TPFanControl running the laptop fan at max speed (the 64 setting).

    - now go and try X9100 with E stepping using the same chipset tricking method, as it would have lower temperatures compared to the X9000 so higher speeds could be very well managed :D

    EDIT: if you'd like to further improve the cooling abilities of the T61, if you have space (just like I have on my 14" standard screen but not on my 14" wide screen T61) then you can drill holes on the plastic bezel just above the fan assembly, which would make the suction air flow cooler due to not having to go through the laptop internals first. Laptop would not look stock anymore of course. Taking off the keyboard produces the same effect, but I'm guessing that would not be permanent solution, hehe.
     
  4. baii

    baii Sone

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    Great find, but still 2 much for me ~~. When i had my T61, I had once used it for 3 month with keyboard lift off cause the fan is semi dead. I had the keyboard attach to cable but slanted resting on the speaker.
     
  5. albertfu

    albertfu Notebook Enthusiast

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    Hi everyone.

    I'm using a Studio XPS 1645 laptop, which has also SLG8SP585V as PLL like XPS 1647 and Acer Aspire 5740G, its chipset is PM55 (Intel(R) 5 Series/3400 Series Chipset Family SMBus Controller - 3B30), Super IO chip is IT8512E per RW.

    I tried to change BCLK with latest version of SetPLL and LUT files provided by courtesy of MotoVlad for SLG8SP585 of his Aspire 5740G (2 versions: with or without Pinmod found in his post in acerfans.ru), but it didn't work on my PC.

    Here are some error messages I got when trying to use SetPLL and RW
    setpll -read ---> "SMBus Error"
    setpll slg8sp585 135 ---> "Failed to set BCLK"
    Click on "Clock Generator" in RW ---> "SMBus return error, clock generator may stop response"
    Click on "SMBus Device" in RW ---> Nothing appears in new window.

    In SetFSB Diagnosis Tab, I got nothing on "PLL Control Registers", and here is what displays in "SMBus I/O Registers" and "Chipset information":

    SMBus I/O Registers ---Base Address 1840h---
    00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
    00 44 00 14 00 D3 08 00 00 00 44 00 00 14 00 07 07

    Chipset Information ---Host Bridge Device/Vendor D1328086h---
    Bus#0 Dev#31 Fnc#0 0fs#00: 3B038086h
    Bus#0 Dev#31 Fnc#3 0fs#00: 3B308086h

    What information should I have (motherboard version, proper SMBus setting, etc.) to get a LUT file which work with my PC? How can I create a working LUT file?

    Thanks in advance
     
  6. User Retired 2

    User Retired 2 Notebook Nobel Laureate NBR Reviewer

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    Good work. You can check the 'disable Turbo' option in Throttlestop to fully disable IDA mode. Then your T9300 will run OK.

    Dell wire their SLG* PLL's SMBUS lines to a MEC* controller

    I had the same PLL in a Dell E4310 with the same errors you describe above. Kizwan also with the same PLL in his Studio 1557 too with the same errors.

    Turns out that Dell wire the PLL's SMBUS lines to an EC controller, (SMSC MEC5045) rather than to the Intel IBEX Peak chipset. Dell have set that MEC controller to hide the PLL. So no amount of using setpll/r-w/setfsb/i2cdump can get the PLL info. What's worse is there are no public datasheets on the SMSC MEC* controllers so we could potentially 'unhide' the PLL.

    As you have an i-core CPU, the PLL supplied can only be pinmodded to run at 100/133Mhz, with 133Mhz being the default. So only way of getting an overclock would be to disassemble the bios to reverse engineer the MEC* controller OR (not feasible) - rewire the PLL's SMBUS lines to the IBEX Peak controller.

    I wish it wasn't so...
     
  7. albertfu

    albertfu Notebook Enthusiast

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    Reverse engineer...

    Thanks a lot for your quick response, it seems to be another dead end here. I kind of have seen that SMSC chip on a HP Envy 15, and will check on my PC to see this damned chip.
     
  8. ThinkLover

    ThinkLover Notebook Consultant

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    Thank you for all your effort here, you did really good job.
    I must say that I'm impressed and very willing to try this by myself.
    The thing is - while I know about computer internals enough to do LCD/Mobo swaps, build PCs etc I know really little about electricity, soldering etc.
    Basicly, what I've ever done is only soldering two wires and etc simple things.
    Taking this into consideration, do you think that I could handle doing this mod by myself?
    If yes, could you explain me please, step by step (pictures are welcomed), what I would need to do to get my T8100 @ 3.2 GHz @ 1.20v?

    I'm young, brave man, who wants to learn new things ;)
     
  9. vwrafi

    vwrafi Notebook Consultant

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    Hello guys. Is there any method to overclock MSI GX660 i5-460m CPU ? Can I use SetPLL, and if yes, which PLL should I use and what is the procedure ?

    EDIT:

    OK, so I have found that my PLL is ICS9LPRS113AKLF. So now I need to creat LUT file for SetPLL. I've did run a free version of SetFSB but I have got strange results comparing bytes. Most of people need to change two or three bytes, but in my example I need to change like 6 or even more bytes ( I am comparing SetFSB Diagnosis with 133MHz FSB and 139MHz FSB ). Strangely, when i change slider to 139MHz in SetFSB and click SET it is just going down to 45MHz and the clock does not change. Can anybody help me with this ?
     
  10. SunnyChrono6

    SunnyChrono6 Notebook Enthusiast

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    Hi guys,can someone help me pinmod my Vostro 1510 with a C2D T5670,Intel 965PM?
     
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