E8400 OC Question, Could It Work? [Dell Optiplex 755]

[kitt]

hey all, update,
i cant for the life of me get any software to tell me what the cpu volts is set at (unless it really is set at 1.2875v which mostly all report). i've tried all sorts (about 10 different programs) including older versions of cpuz and hwmonitor. Tech Tweaker: regarding cpuz, it seems that in the .ini file, you can change between sensor ON or OFF to get the actual cpu volts reading or what the cpu is 'expected' to be.. but anyway it doesnt make any difference here, it reports 1.2875 regardless of the .ini setting, as well as trying older versions of cpuz. im wondering if the problem is the fact that my stock dell mainboard is very limited or just plain sucky... not sure really.

temperatures are all ok for cpu, gpu, hard drive, mainboard so no problems there afaik

i would be surprised if the cpu was indeed set at 1.2875v as the pc boots every time, but did not do so before i did the voltage pad mod. i suppose a way to confirm if there is a volts change is if i go back and remove the voltage pad mod and see if the pc boots at all. i would be happy to try to get a cpu volts reading using a multimeter but i did a google search and cant find anything regarding reading cpu voltage with a multimeter under LGA775.

i ended up disabling a lot of stuff in bios (cdrom drive (unplugged also), front usb ports, some of the rear usb ports (leaving 4 in total, that's all i need), serial port, printer port, onboard network, onboard modem, and ive got to the point that, if i dont run any stressing software, the pc seems fine (ran it for an hour or two) with no crashes. when i run cpu stress software though, the pc lasts about 10 minutes before getting a crash (BSOD).. the cpu temp under stress doesnt rise above 60c. note: i did notice that in the stress software (called heavyload) it had the option to just stress the cpu and not the gpu. so i turned off the gpu stress option, but still get the eventual BSOD.

well it feels like i am pretty close anyway i think, i do have a different video card i can try so i expect i will do that. i dont know whether i should raise the volts a bit more to around 1.4v, or instead, firstly troubleshoot further regarding my OS (winxp 64), video card, drivers etc

i will give memtest+ a try also

ok i will report with any progress.

 

[kitt]

success
i wanted to report here so this thread is not 'left in the open'

ok so to summarise, after giving up on an E8400 cpu because my dell mainboard would not support overclocking it to 1600MHz fsb, i was attempting to overclock an E7600 to 3.8ghz by raising the fsb from 1066MHz to 1333MHz. after attempting a BSEL cpu pad mod to reach this goal (because the dell mainboard does not allow any overclocking features in the BIOS), my dell pc would not boot windows (the cpu voltage as this point was still set at stock 1.2875v).

i then raised the voltage via a VID cpu pad mod, to 1.3875, which, although i could not seem to get my pc/windows/overclocking/monitoring software to report that my cpu volts had increased, i assumed the cpu volts pad mod was a success, because now i could actually boot into windows instead of getting a crash. i had a problem remaining though, in that, running cpu stress software, i would get a crash (BSOD) after about 10 minutes.

ok so what i have done next is, i decided to raise the volts further, via another VID cpu pad mod, this time i raised it to 1.4125v. this now seems to have been a success regarding the system stability. i still get the issue of my pc/windows/overclocking/monitor software all reporting that my cpu is running at stock 1.2875v, but i believe this is not the case and is simply down to either a windows xp 64bit, drivers issue or dell mainboard/system issue regarding reporting correct readings.

anyway, so now with the cpu at 1333MHz fsb, and volts set at 1.4125v, i ran the heavyload software for one hour, and everything was ok, no crashes, no problems. the temps did get high (as im using the stock dell air fan/heatsink), but they did not go above 65 degrees at full load (idle was around 43 degrees), and this is using cheap thermal cpu paste (applied in a hurry and not particularly efficiently), so i expect the temps to go down (hopefully) by some degrees when i use a much better quality thermal paste applied with more care. i may also try heatsink lapping, as (in my opinion) even a drop of a couple of degrees by doing that, would be considered a success. EDIT: i decided to lap both my heatsink and cpu, plus use some high quality thermal paste, and now get a max cpu stress of 55 degrees, so im pleased there. idle temp is around 42 degrees.

so i think that's about it, the project has been a success and im happy. im not bothered if the raising of the volts of the cpu and the extra heat shortens the lifespan of the cpu, because this class of cpu is now old, and cheap. as the months go on, it seems that purchasing E7600 cpu's (and most other core2duo's in general) from eg. ebay is becoming very cheap, so i will simply buy some more of them if necessary. plus i wont be using the dell pc very much (a few times a week perhaps, for a few hours), and only to play some emulated video games, most of which wont be maxing out the cpu anyway.

thanks very much everyone for your help, much appreciated and im happy. it was good fun, i think im now officialy addicted to overclocking

finally i saw this chart on the internet below -- how accurate it is i dont know (eg. depending on which OS you are running), but it's interesting perhaps anyway... (and in my case, it helped me, as regarding a blue screen i got during the project, i got the error code 0x1E, which according to the chart below, advised me to raise vcore, which i did, and the problem was fixed)

cheers!

_________________________________________

Common BSOD Error Codes for Overclocking

0x101 = increase vcore
0x124 = increase/decrease QPI/VTT first, if not increase/decrease vcore...have to test to see which one it is
on i7 45nm, usually means too little VVT/QPI for the speed of Uncore
on i7 32nm SB, usually means too little vCore
0x0A = unstable RAM/IMC, increase QPI first, if that doesn't work increase vcore
0x1A = Memory management error. It usually means a bad stick of Ram. Test with Memtest or whatever you prefer. Try raising your Ram voltage
0x1E = increase vcore
0x3B = increase vcore
0x3D = increase vcore
0xD1 = QPI/VTT, increase/decrease as necessary, can also be unstable Ram, raise Ram voltage
0x9C = QPI/VTT most likely, but increasing vcore has helped in some instances
0x50 = RAM timings/Frequency or uncore multi unstable, increase RAM voltage or adjust QPI/VTT, or lower uncore if you're higher than 2x
0x109 = Not enough or too Much memory voltage
0x116 = Low IOH (NB) voltage, GPU issue (most common when running multi-GPU/overclocking GPU)
0x7E = Corrupted OS file, possibly from overclocking. Run sfc /scannow and chkdsk /r

BSOD Codes for Sandy Bridge

0x124 = add/remove vcore or QPI/VTT voltage (usually Vcore, once it was QPI/VTT)
0x101 = add more vcore
0x50 = RAM timings/Frequency add DDR3 voltage or add QPI/VTT
0x1E = add more vcore
0x3B = add more vcore
0xD1 = add QPI/VTT voltage
“0x9C = QPI/VTT most likely, but increasing vcore has helped in some instances”
0X109 = add DDR3 voltage
0x0A = add QPI/VTT voltage

For a complete list of BSOD error codes that may or may not be related to overclocking, see here:
http://www.aumha.org/a/stop.php#0x9c