mitchellvii Posted March 26, 2009 Posted March 26, 2009 Ok, this is weird. Just got new Phenom II 720 BE on my ASUS M3A78-T 790GX MB. Initially I tried overclocking it using AMD Overdrive Software and got to a stable 3.65 at 18 x 200 x 1.475v. No worries. Then I thought that maybe it would be even better if I OC'd it directly in the BIOS. To my surprise and consternation, no dice. ANY OC in the BIOS using the increased multiplier causes BOD on boot. ACC adjustments? Nope, also BOD. So what the heck is going on? Others with this MB seem to be having no issues. I have downloaded the latest BIOS so that should be ok. P.S., It also seems that the ACC trick for unlocking the 4th core on the 720 doesn't work with the M3A78-T (I can live without that, of course, but would have been fun to try...) Quote Share this post Link to post Share on other sites More sharing options...
The Smith Posted March 26, 2009 Posted March 26, 2009 The unlocking of the fourth core depends on the processor, as long as the motherboard has the Advanced Clock Calibration. Some CPUs can be unlocked whereas some others cannot. Quote Share this post Link to post Share on other sites More sharing options...
Verran Posted March 26, 2009 Posted March 26, 2009 The unlocking of the fourth core depends on the processor, as long as the motherboard has the Advanced Clock Calibration. Some CPUs can be unlocked whereas some others cannot. Also, just because the fourth core unlocks, doesn't mean it'll be stable. Be very careful of that, too! As for the BIOS overclocking, have you tried increasing the FSB? Does that cause BSODs too? Quote Share this post Link to post Share on other sites More sharing options...
Nuclear Posted March 26, 2009 Posted March 26, 2009 First...let's go through a couple of things 1. Do not have ACC enabled for your Phenom II chip. ACC was a Phenom I feature and is not supported by the newer Phenom IIs. It may work but it will cause major system instability when attempting to overclock 2. Disable all of your spread spectrum settings 3. Leave all of your voltages at auto, except for your vcore. 4. Lock your HT and NB speeds at their default values 5. If you are running 1066 RAM, drop it down to 800 and manually set the timings Quote Share this post Link to post Share on other sites More sharing options...
Baulten Posted March 26, 2009 Posted March 26, 2009 Yeah, scrap ACC. Doesn't work for almost all Phenom II's. Quote Share this post Link to post Share on other sites More sharing options...
The Smith Posted March 26, 2009 Posted March 26, 2009 Yeah, scrap ACC. Doesn't work for almost all Phenom II's. Except it's the setting that can enable the fourth core But yeah if it cannot be enabled, leave it disabled. Quote Share this post Link to post Share on other sites More sharing options...
mitchellvii Posted March 26, 2009 Posted March 26, 2009 Ok, so you are saying I should leave all votages and timings except the CPU alone? Hmmm, I have seen many reliable overclockers who are adjusting the NB as well. Is this a bad idea? Quote Share this post Link to post Share on other sites More sharing options...
Nuclear Posted March 26, 2009 Posted March 26, 2009 Ok, so you are saying I should leave all votages and timings except the CPU alone? Hmmm, I have seen many reliable overclockers who are adjusting the NB as well. Is this a bad idea? You probably will need to adjust your secondary voltages, i.e. NB / NB-CPU / SB / HT voltages at some point...but you always want to start with the simplest voltage adjustment and work from there. For instance: My PII 940 will run at 3.7GHz with only a vcore change perfectly fine, but anything over that and I need to start tweaking my secondary voltages. At some point you will need to bring the NB speed up to keep the system happy with the increased clock speed and that's when you need to adjust those voltages. Adding voltage to those areas will increase the temps also, so make sure to keep an eye on them. Quote Share this post Link to post Share on other sites More sharing options...
Waco Posted March 26, 2009 Posted March 26, 2009 I wouldn't tweak anything except the multiplier and vcore really... Quote Share this post Link to post Share on other sites More sharing options...
mitchellvii Posted March 26, 2009 Posted March 26, 2009 Hmm, ok. How do I go about overclocking the Northbridge Speed? AOD doesn't seem to offer an option for increasing that and anytime i change anything in the BIOS I get instant BSOD (don't understand why). For some reason, this chip refuses a BIOS overclock but does AOD happily. Any suggestions on voltages for: NB VID DDR NB HT SB SidePort I have no idea where to set these. I am running an Asus M2A78-7 790 GX MB with 4 gigs 6400 DDR2 Ram. P.S., What is the difference between NB VID (voltage) and NB (voltage)? I have been trying some of the settings others have suggested to be happily stable onlie and they are istant BSOD's. Don't know if they are lying or I have a bad chip. Quote Share this post Link to post Share on other sites More sharing options...
mitchellvii Posted March 26, 2009 Posted March 26, 2009 Right now my AOD Benchmark is 10,221 - which I have been told is quite good. I am running an 8800 GT GPU. Quote Share this post Link to post Share on other sites More sharing options...
mitchellvii Posted March 27, 2009 Posted March 27, 2009 Wow, just ran 3DMark06 on my 8800 GT with the 720 BE. My score jumped from 11,500 to 13,500! Wow. 2000 poinst with just a new CPU - I'm shocked. 13,500 on an 8800 GT is great. Quote Share this post Link to post Share on other sites More sharing options...
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