Orcin
1000+ Head-Fier
- Joined
- Apr 21, 2007
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Assuming that you can boot into Windows without incident, how do you tell if your overclock is unstable? It's a good sign that you have a problem when you get corrupt data in an application. You can be sure when you run a stress test and get a blue screen of death in two seconds. I'll lay out the story, but there is a newbie mistake and a veteran good move in this tale - see if you can spot them both.
Our saga starts with a very stable overclock at 3.5GHz with many settings on Auto. I thought it would be beneficial to try to run lower voltages than the auto settings, and I also wanted to see if I could improve my memory timings over "auto". Before I started, I saved my current bios settings into a profile and began to poke through the options.
First, I took two key voltage settings off "auto" and set them manually. I lowered the memory voltage from 1.6v to 1.5v, because I was running the memory at its rated frequency of 1333Mhz and it should be able to do that at stock voltage. I lowered the QPI/VTT voltage to 1.34v from 1.42v, because 1.34v was the highest setting that did not give a "pink warning" when it was assigned.
Next, I took the memory timings off "auto" to assign them manually. CPU-Z had reported that my memory was running at 9-9-9-24. It is rated at 6-8-7-16, so I was very sure I could do better than the auto settings. The bios had recommended values of 8-8-8-20, so I thought that was a good start and keyed these values in leaving the other settings on auto.
I re-booted succesfully, and noticed one good thing right away. Previously, my motherboard LED's had reported cpu voltage as yellow (warning stage 2 of 3... the third being red) and the memory and northbridge at green (warning stage 1 of 3... no lights = no warning). The lights had now changed to green for cpu and no lights for the other two. So I had obviously changed the voltages for the better. I checked the memory in CPU-Z, and my target timings were now being reported as the actual. So everything must have worked - so far so good.
I needed to sync my iPod so I opened iTunes and plugged it in. The sync ended and I took a look at my recently played playlist. Hmmm... it shows some songs as being played twice in the past two days, but I know I only played that album once. I'll fix those playcounts later, but just let me sync again to see what happens. This sync caused two files to be copied to the iPod, but I had done nothing to change those files. Ok, this is weird... maybe I am unstable!
I decided this was a good time to run OCCT for an hour and see what happens. I started the program and it gave me a BSOD in two seconds. Obviously not stable.
Did you spot the veteran move? Well, here it comes... I rebooted into the bios and hit "Load Profile". I was back up to my stable settings in the time it took to reboot. ALWAYS save a stable profile and don't trust the "load last good" option because you might get stuck in a reboot cycle or not notice your errors right away.
The newbie mistake... well, I made so many complex changes that I have no idea what caused the instability. Was it setting the voltage too low, and if so which voltage? Or were the memory timings the cause?
I have a suspicion that it was all of the above. A little research revealed that my memory does not like timings of 8-8-8-20, instead it prefers 8-8-8-21. I got a BSOD error 124, which usually indicates low voltage on the northbridge (QPI/VTT). And many people say that even a normal memory timing and frequency requires additional memory voltage over stock when the cpu is overclocked.
So any of my settings could have caused the instability, and it might be that the combination of errors saved me some frustration by failing quickly before I had a chance to corrupt my OS. The only way to know for sure is to go back at the job tonight and try one change at a time, more gradually, with stress testing after each change. I would have done this last night, but I was running short of time and I always like to end the day on a positive note. I had a computer that was reporting all of its readings just as before and was able to re-sync my iPod without unusual results, so I decided to stop while I was ahead.
Lesson learned... fortunately without penalty... at least none that I know of...
Our saga starts with a very stable overclock at 3.5GHz with many settings on Auto. I thought it would be beneficial to try to run lower voltages than the auto settings, and I also wanted to see if I could improve my memory timings over "auto". Before I started, I saved my current bios settings into a profile and began to poke through the options.
First, I took two key voltage settings off "auto" and set them manually. I lowered the memory voltage from 1.6v to 1.5v, because I was running the memory at its rated frequency of 1333Mhz and it should be able to do that at stock voltage. I lowered the QPI/VTT voltage to 1.34v from 1.42v, because 1.34v was the highest setting that did not give a "pink warning" when it was assigned.
Next, I took the memory timings off "auto" to assign them manually. CPU-Z had reported that my memory was running at 9-9-9-24. It is rated at 6-8-7-16, so I was very sure I could do better than the auto settings. The bios had recommended values of 8-8-8-20, so I thought that was a good start and keyed these values in leaving the other settings on auto.
I re-booted succesfully, and noticed one good thing right away. Previously, my motherboard LED's had reported cpu voltage as yellow (warning stage 2 of 3... the third being red) and the memory and northbridge at green (warning stage 1 of 3... no lights = no warning). The lights had now changed to green for cpu and no lights for the other two. So I had obviously changed the voltages for the better. I checked the memory in CPU-Z, and my target timings were now being reported as the actual. So everything must have worked - so far so good.
I needed to sync my iPod so I opened iTunes and plugged it in. The sync ended and I took a look at my recently played playlist. Hmmm... it shows some songs as being played twice in the past two days, but I know I only played that album once. I'll fix those playcounts later, but just let me sync again to see what happens. This sync caused two files to be copied to the iPod, but I had done nothing to change those files. Ok, this is weird... maybe I am unstable!
I decided this was a good time to run OCCT for an hour and see what happens. I started the program and it gave me a BSOD in two seconds. Obviously not stable.
Did you spot the veteran move? Well, here it comes... I rebooted into the bios and hit "Load Profile". I was back up to my stable settings in the time it took to reboot. ALWAYS save a stable profile and don't trust the "load last good" option because you might get stuck in a reboot cycle or not notice your errors right away.
The newbie mistake... well, I made so many complex changes that I have no idea what caused the instability. Was it setting the voltage too low, and if so which voltage? Or were the memory timings the cause?
I have a suspicion that it was all of the above. A little research revealed that my memory does not like timings of 8-8-8-20, instead it prefers 8-8-8-21. I got a BSOD error 124, which usually indicates low voltage on the northbridge (QPI/VTT). And many people say that even a normal memory timing and frequency requires additional memory voltage over stock when the cpu is overclocked.
So any of my settings could have caused the instability, and it might be that the combination of errors saved me some frustration by failing quickly before I had a chance to corrupt my OS. The only way to know for sure is to go back at the job tonight and try one change at a time, more gradually, with stress testing after each change. I would have done this last night, but I was running short of time and I always like to end the day on a positive note. I had a computer that was reporting all of its readings just as before and was able to re-sync my iPod without unusual results, so I decided to stop while I was ahead.
Lesson learned... fortunately without penalty... at least none that I know of...
