G5rocks Posted November 1, 2007 Share Posted November 1, 2007 I'm trying to overclock my Q6600 B3. It's running fine at 2.8GHz, vcore on auto - no errors in Prime95 (10 hours test) At 3GHz i'm getting errors in Prime95 - i also saw 2 Kernel Panics in Leopard while at 3GHz Already tried to raise Vcore voltage - my last try was: Bus 333, RAM 667, Multiplier 9, Vcore 1.4v (1.4 is the BIOS setting - all tools report lower voltage.) Going higher than 1.4v (BIOS setting) is not a good idea isn't it? Or is it really undervolting that much? (Idle 1.36V - stressed 1.32V) Temperatures were good at 3GHz and lower voltages but with this last setting it goes up to 68°C during Prime95 test. I'm a n00b - maybe someone with the same setup can help me? (i know... all Q6600 are different) Link to comment Share on other sites More sharing options...
G5rocks Posted November 2, 2007 Author Share Posted November 2, 2007 Just tried 2.9GHz vcore set to 1.35v in bios - prime95 error after 10 minutes Link to comment Share on other sites More sharing options...
shoarthing Posted November 2, 2007 Share Posted November 2, 2007 . . I usually sort out the max 'happy' FSB first: drop the multiplier to (say) 7 & see if you can run the thing at 400MHzx7 - you will almost certainly need to increase NBridge voltage, & give it a touch more SBridge volts; but it shouldn't need more vcore to the CPU. This gives you decent memory bandwidth [i am assuming you can run your posh Mushkin stuff at 1:1 & 400MHz - check the recommended VDIMM for various speeds]. If this is stable, increase the multi to 8x & see how far you can get . . 3.2Ghz is a fair old 'clock with your quad's stepping; but it may be possible. Link to comment Share on other sites More sharing options...
G5rocks Posted November 2, 2007 Author Share Posted November 2, 2007 Specs of my RAM is 800MHz 4-5-5-12 2.0-2.1V Whats the recommended voltage for the north bridge? Where do i start when i leave "auto"? I just made some more tests: 3,15GHz (forgot to set the multiplier ) Vcore auto - Bus 350 - RAM 700MHz SPD on - Prime 95 failed 2.8GHz Vcore auto - Bus 350 - RAM 700MHz SPD on - Prime 95 failed 2.8GHz Vcore auto - Bus 311 - RAM 622MHz 4-4-4-12-4 - Prime 95 failed 2.8GHz Vcore auto - Bus 311 - RAM 622MHz 5-5-5-18-6 - Prime 95 passed (almost same setting that i had successful tested 10 hours in prime except ram timings which were SPD on) 2.8GHz Vcore auto - Bus 350 - RAM 700MHz 5-5-5-18-6 - Prime 95 failed 3.0GHz Vcore 1.4V - Bus 333 - RAM 667MHz 5-5-5-18-6 - Prime 95 failed Maybe my board does not like more than 311MHz? Link to comment Share on other sites More sharing options...
thefinalprophecy Posted November 2, 2007 Share Posted November 2, 2007 Does your CPU register right in "About This Mac"? I have the same CPU as you, and whether it was Kalyway 10.4.10 or Leopard 10.5, it shows up as Unknown CPU 2.6ghz, 1 cpu, 4 cores. Link to comment Share on other sites More sharing options...
G5rocks Posted November 2, 2007 Author Share Posted November 2, 2007 no - but in jas 10.4.9 with 10.4.4 loginwindow it worked Link to comment Share on other sites More sharing options...
shoarthing Posted November 2, 2007 Share Posted November 2, 2007 . . . Whats the recommended voltage for the north bridge? Where do i start when i leave "auto"? . . you might start with a re-read of this post: the Northbridge [mch] needs up to 1.65 [depending on how well it is cooled] for 400MHz+ Link to comment Share on other sites More sharing options...
Loyx Posted November 3, 2007 Share Posted November 3, 2007 I needed vCore=1,5v to get my E6600@3.2 stable. Just check temps with TAT or SpeedFan when stressing cpu (I used orthos).. Never over 60C. 45 on idle... The Ram is working 2.1v 4-4-4-12 Link to comment Share on other sites More sharing options...
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