Hardware OC'd MP1,1 Octo Proof of Concept

Discussion in 'Mac Pro' started by drrbc, Mar 24, 2011.

  1. drrbc macrumors newbie

    Oct 29, 2009
    I have up and running a 3.3Ghz MacPro1,1 "OctoCore".

    Originally with 2X 5160's, I came into two X5350's (2.66/1066). With the BSEL and VID mods the FSB was raised to 1333, which forced the CPU to 3.3Ghz. Initially unstable, a VID was performed raising the Vcore eventually to 1.425 which proved satisfactory.

    Heat issues prevented stressing the machine causing panics within 1 minute of Handbrake encoding being started, though the computer was stable for web browsing, email, etc.

    A cooling system adapted from PC water cooling systems was successful. This was tied into a home-built geothermal ground loop to prevent heat buildup in the office.

    A proof of concept video has been placed on YouTube at:


    Thank You.
  2. Joshuarocks macrumors 6502


    Mar 12, 2011
    Somewhere in Cyberspace

    Excellent work!! I take it you are a fan of liquid cooling? Liquid cooling is cool, but sad to say those who have owned Power Mac G5 Dual 2.5's and dual 2.7s and to a smaller extent, the Quads experienced coolant leaks due to the problems with Delphi, though I haven't heard of any problems with Panasonic. Be sure you aren't using Delphi based tubing.. I am learning more about how to safe guard my newly bought Power Mac G5(used as a second-hand system) and its LCS. WHat can you recommend for me to insure that the G5's cooling system won't leak?

    Btw, I also have a 2010 Mac Pro 6-core, but most of what I do on that is with handbrake and dvd encoding.
  3. Renderz macrumors 6502

    Feb 27, 2004
    Wow! You're much braver than I am. Well done!
  4. Cindori macrumors 68040


    Jan 17, 2008
    There's a guide to bsel mod here:


    I think you're the first to use this combo though :D
  5. mif macrumors regular

    Feb 16, 2010
    uh, what a pro. I only fiddled with twin-cam G4's.
  6. Graeme43 macrumors 6502a


    Sep 11, 2006
    Great Britain (Glasgow)
    Is it viable to upgrade a Mac Pro 1,1? I have a 03/2007 1,1 and was looking to double the cores from 4 to 8 as they're a lot cheaper now than when new

    I don't want to get eliminated through a stupid EFI32 issue.. If Apple decide to block an OS installing through EFI.. it will be annoying since those people who hack OS X to run on PCs will get around it. yet real Macs will be shunned! :( :D

  7. neckarb macrumors regular

    Jun 29, 2007
    Wow that's awesome dude, how did you raise the VID? I've been trying to do the same thing!
  8. ListedFirst.com macrumors newbie

    Dec 28, 2009
    Nice mod! I did this back in 2008 with some ES CPUs, the only way I could get it to run stable was with Liquid Nitrogen cooling the bugger... needless to say, it didn't remain overclocked very long!

    Give this one a go and let me know what happens!


  9. green86 macrumors 6502


    Sep 27, 2007
    North Carolina
    Have you run GeekBench yet? What were the results?
  10. drrbc thread starter macrumors newbie

    Oct 29, 2009
    Thanks for your replies

    Sorry to take so long getting back. Was helping a friend with their 1,1 and 5770 and came upon my own post.

    I'm writing an article for the nice folks at OWC detailing the experience. Just got a little delayed due to work, tax season, CME's, etc. Well, that and the fact obsessions tend to wear one out. Still not finished cleaning the office.

    But it should be complete, including a reiteration of the BSEL and VID mods. I'm hoping the will be putting out part 1 soon.

    Warmest regards to all, and please keep looking for ways to OC the Mac.


    2X Intel Confidential X5350's at 3.3Ghz
    Koolance and EK waterblocks to GeoThermal loop cooling
    12GB 667 FB-DIMMs
    2.5TB (total) twin internal striped RAID arrays
    .45 Longslide (laser sighting)
    ATI 5770 to 2X 30in. Apple Cinema Displays
    Phased plasma rifle (40 watt)
    Internal Pioneer BDR-205
  11. Elisha macrumors 6502a


    Nov 21, 2006
    Do you have a link to the VID mod?
    Also don't these chips have a default voltage of 1.5v anyway compared to the rest of the 5300 series which are 1.35v and lower?

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