i5 750 Lynnfield overclocking

Discussion in 'Intel x86 CPUs and chipsets' started by trodas, Jul 20, 2014.

  1. trodas

    trodas Member

    Sep 5, 2004
    Czech republic
    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:

    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:

    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 :D Currently there is just a suxxking default intel noisy heatsink, so it is just for the testing:

    [​IMG] [​IMG] [​IMG]


    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 :)
  2. hawpinghaxbag

    hawpinghaxbag Member

    Jun 6, 2005
    Your mum's place
    Hmmm, i got a 760 (2.8ghz lynnfield) @4.0 back home but its got a Noctura D14 cooler on it

    ram is corsair 2000mhz stuff with extreme memory profile or something, been like 4 years since ive set it up so i cant really remember much
  3. OP

    trodas Member

    Sep 5, 2004
    Czech republic
    Ugh, that seems a nice overclocking result. Time to get a nice cooler for it then ;)

    And are there some tips for optimalitation of Windows 7 settings? Besides disabling the core parking?


    So, little test. 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...


    ...it still freeze in the test, tough :mad:
  4. C-BuZz

    C-BuZz Member

    Jan 24, 2002
    Melb, East
    Crank the volts up a bit don't mess about. If it's cool you got nothing to worry about.

    Most of these hit 4 pretty easy. I remember mine was @ 4.2ghz back in the day.
  5. t8y

    t8y Member

    May 5, 2002
    SA, 5011
    seems to me you've found the base clock wall at ~215 (may go higher with more VTT however, or dropping the memory multi (which will also be increased with base clock) or upping the memory voltage).

    crank the vcore and up the multiplier now, you have a fairly low multi set atm (17/18).
    backing off the bclk to 200 and upping multi to 20 will give you your 4ghz target, just leave everything where it is currently besides those 2 values and adjust the vcore til its stable in (insert preferred stress test/game here)

    still strong CPUs these so adding some clocks should hold off the upgrade bug :thumbup:

    edit: CPU cooler change not a bad idea, though... not sure on temps but the stock cooler surely doesnt have much left in it.
    anything that fits current socket 1150/1155 CPUs will fit yours too :)
    Last edited: Jul 23, 2014
  6. James086

    James086 Member

    Mar 25, 2010
    The i5 750 is an excellent chip. I had it at 4.0 GHz easily. It's been too long to remember the voltages but I remember having a lot of fun with it. :thumbup:

    I seem to remember avoiding anything over 1.40 volts, but I managed to get it stable at 4 GHz well below that.
  7. wolfie870

    wolfie870 Member

    Oct 7, 2009
    Hey mate, Screenshot of my i5 750 @ 4.0ghz, might help you with volts, BCLK etc.


    This was 24/7 since 2009, still going strong today in my brother's comp at the same clocks.

    Under a Noctua CPU cooler (2 x 120mm fans), temps hovered around 50-60 across a range of games and applications.

    It could run up to 4.3ghz with slightly higher voltage (can't remember exactly now), but the temps got a bit too warm for my liking.

    Hopefully that helps! Unreal chip, massive OC performance of 50%+ clock speed.

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