Results 1 to 2 of 2

Thread: i5 750 Lynnfield overclocking

  1. #1
    Registered User
    Join Date
    Feb 2009
    Posts
    99

    Question i5 750 Lynnfield overclocking

    I got a bit more rencent CPU - i5 750 Lynnfield with somewhat decent mainboard (MSI P55A-GD55 - Intel P55 chipset socket 1156 mainboard rev. 2.1) and since I was not overclocking such CPU ever, I would like to get some tips from guys that are sucesfull and know, what these chips want and how to get them to run fastest.

    The basic specs of my i5 750 Lynnfield are 2.66GHz with turbo 3.2GHz, witch looks slow to me.

    About the overclock - well, I just at first used the OC genie, but that won't get me far (3GHz base clock, IIRC 3.4GHz turbo).

    First I just copied what the OC genie do, but then I get into some manual tweaking. OC genie pushed Vcore hard:
    Vcore +0.278V
    VTT - 1.314V
    Vdram - 1.701V

    I find out, that with Vcore just mere 1.112V it do 3578MHz stable:

    http://valid.canardpc.com/aseucr

    However I hit the wall with 3.6GHz cannot run stable - it always freeze, even with much higher Vcore, so the problem must be somewhere alse.

    Bumping the Bus speed from 210 to 215 resulting in 3663MHz, witch always freeze the machine during tests, even with lowered the memory speed to make sure, that this is NOT because of memory cannot cope with the speed, especially with tightened timings 9-9-9-18 CPU-Z validation can be made, tough:
    http://valid.canardpc.com/fhq0ut

    But it is not stable. I overheard the VTT might need a bit more "love", but I figured that I better ask fellow overclockers first Currently there is just a suxxking default intel noisy heatsink, so it is just for the testing:



    ...

    Futhermore I would like to ask about some bios settings (features of the i5, for example), witch are suggested to be disabled/enabled in order to get maximum speed. IIRC one czech testing server always disable virtualization, so that probably should be a good start. Of course disabling the Spread Spectrum to get overclocking going, but there are far more options I'm interesed about, like:

    Intel EIST - IMHO off, because this is not NTB that need baterry support and I want always full clock
    Intel C-State - IMHO off, because conserving the energy is not the speed goal
    C State package limit Setting - IMHO off, because I did not want any regulations
    C1E Support - IMHO off, because sky is the limit and I don't want any other limits there
    OverSpeed Protection - IMHO off, even MSI recommend that for OC
    (between these CPU features are in manual mentioned Hyper-Threading Function. but I did not have it in bios)
    Execute Bit Support - I leaved this on, but speed wise off is better, no?
    Set Limit CPUID MaxVal to 3 - IMHO off, because who cares about old systems when overclocking, right?
    Intel Virtualization Tech - IMHO off for speed?
    Intel VT-d - IMHO off for speed?
    Active Processor Cores - All - simple there, huh?

    Mainboard manual: http://www.mediafire.com/?4vdh50m7ta0995w - https://www.oboom.com/RL8DUVCJ

    And then there are the voltage settings:
    CPU Voltage(V) - +0.105V
    CPU VTT(V) - 1.314V
    CPU PLL Voltage(V) - Auto
    DRAM Voltage(V) - 1.701V
    DDR_VREF_CA_A(V) - Auto
    DDR_VREF_CA_B(V) - Auto
    DDR_VREF_DA_A(V) - Auto
    DDR_VREF_DA_B(V) - Auto
    PCH 1.05(V) - Auto
    ...any suggestions about how to break the 3.6GHz wall?

    And the there are the settings like:
    PCI Latency Timer - IMHO the smaller the better, choosen 32 as lowest value
    HPET - High Precision Event Timers - no idea what to set, maybe off for speed and less precision?
    TCG/TPM SUPPORT - Trusted Platform Module can be enabled/disabled - what is best for speed?

    ...and don't even get me started about the memory settings. There is 8G consisting of:
    2x 2048MB DDR3 1600MHz G.Skill RipJaws 9-9-9-18 1.7V (F3-12800CL9D-4GBRL)
    2x 2048MB DDR3 1600MHz Kingston HyperX 9-9-9-18 1.7V (KHX12800D3K2/4G)

    So far these seems stable at 860MHz (1720MHz effective) and 1.701Volts, so maybe later some possible finetuning could get handy too Current ram settings:

    Memory Timing - 2T (Suuuuuuxxx!)
    CAS - 9
    tRCD - 9
    tRP - 9
    tRAS - 18
    tRFC - 88
    tWR - 12
    tWTR - 6
    tTRRD - 5
    tRTP - 6
    tFAW - 24
    B2B-CAS Delay - 0

    tdrRdTRd - 6
    tddRdTRd - 7
    tsrRdTWr - 11
    tdrRdTWr - 11
    tddRdTWr - 11
    tsrWrTRd - 16
    tdrWrTRd - 4
    tddWrTRd - 4
    tdrWrTWr - 7
    tddWrTWr - 7
    tsrRdTRd - 4
    tsrWrTWr - 4
    Round Trip Latency - 59 (channel 1) / 61 (channel 2)

    Surely something could be made faster there
    Disclaimer: Any errors in spelling, tact, or fact are transmission errors.

  2. #2
    Registered User
    Join Date
    Feb 2009
    Posts
    99
    So I bumped the Vcore to +0.204V (still far cry from +0.278V that the OC genie used) and bumped the VTT to 1.386V (last one before the color get red in the bios) - and x18 multiplier and hell, it booted right away! Whoa!
    3780MHz is a bit step from 3578 ... Holly, holly...


    http://valid.canardpc.com/kut8p6

    ...it still freeze in the test, tough
    Disclaimer: Any errors in spelling, tact, or fact are transmission errors.

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •