Overclocking and power supplies

[JSTpt1022]

Hi all,

I've never really messed around with overclocking too much, despite having the gear for it as well as truly epic cooling capacity. But I recently got into folding@home and I've started dabbling a little bit in an effort to lower my frame times. First, I guess I should run down the relevant equipment:

CPU: E6750 (stock is 2.66)
MB: ASUS Maximus Formula
Memory: Corsair XMS2-6400 2GB (stock 800MHz)
PSU: Antec NEO HE 500

Now I normally just use the built in utilities that came with the ASUS to do a little light overclocking now and again. I either set and forget at 2.8GHz or so, or I use the dynamic booster that auto scales the cpu based on usage.

The problem came when I got ambitious and, again using the built in utilities, pushed the cpu to 3.6 and the memory to 1066. The system was at first unstable, and then locked all together, forcing me to reboot at a lower frequency. At first I said, no big deal, it just can't handle it. But then I thought, wait a second, why not?!

Today I've been manually setting the cpu frequency while folding and monitoring things a little more carefully. What I've found is quite disturbing. In the past I have primarily concerned myself with temperature and, since the C2D and MB practically run at room temperature all day, I haven't been worried. Today I started looking at voltages and was shocked to find that my +5, +3.3 and +12 rail voltages are all under:

Current:
+5 = 4.97
+3.3 = 3.14
+12 = 11.93

The last time I paid attention to these numbers they were all considerably over. Additionally, PC Probe II is showing my northbridge, southbridge2 and front side bus voltages in red. I don't know enough to know what these should be but here they are:

SB2 = 1.97
FSBT = 1.42
NB = 1.49

Here are my questions. Is it safe to assume that power supply is the source of my stability problems at high overclocks? If so, and there isn't some other problem that my lack of knowledge is overlooking, how soon should I be looking for a new PSU? Also, I know that OS overclocking utilities aren't the best as far as control and good results, any suggestions for settings in the BIOS?

Sorry for the long post. Any help or comments, positive or negative will be appreciated.

Edit: I should have mentioned that these readings were taken while folding a large work unit with winsmp w/affinity changer. Meaning that both cores are pinned at 100% usage continuously and my memory usage is roughly 45%.

[nysulli]

your voltages are pretty typical of what any powersupply puts out, I wouldn't point your finger in that direction necessarly

3.6 ghz might just be beyond what your cpu can handle, at least at your current voltages, along with your other components, in order to get that far you'll probably have to up cpu core voltage along with a few other tweaks, google e6750 overclocking and you might find some helpful info

[skyline889]

The voltages are pretty normal and 500watts should be more than enough for your setup. This is going to sound really stupid but I have to ask, you have been increasing vcore as you up the FSB right? The higher you go up, the more vcore you need. You also might need to check your ram voltage. If 1066 is not it's native speed, you will need to increase voltage and loosen up timings, that is if you've already tested that it will run at those speeds stably. If you have been, you might just have reached the wall of your CPU or motherboard, though that 6750 should've reach 3.6 easily with proper cooling.

[zyxwvutsr]

Unless you got those voltage readings from a voltmeter/multimeter, I would not worry about those readings that you got.
If those readings happen to be correct and correspond to your non-overclocked setup at idle, then I would start scratching my head considering that you have 500 watt PSU feeding a relatively non-power hungry setup (although I don't know what video card you have).
Try running your computer at full load and compare the voltage readings to the voltage readings that your computer would get at idle. If there are no big drops in the voltages, your PSU should be able to handle overclocking.

[glitch39]

just like our rigs, you are limited by the weakest link. however, easier said than down. you have to look at each component to see if that is your weak link.

got a 2.2 C2D CPU running at 3.5 now and pretty stable. usual checkpoints are:

Power supply
CPU
motherboard
cooling system
Memory

hope that helps

[analogbox]

Originally Posted by skyline889

The voltages are pretty normal and 500watts should be more than enough for your setup. This is going to sound really stupid but I have to ask, you have been increasing vcore as you up the FSB right? The higher you go up, the more vcore you need. You also might need to check your ram voltage. If 1066 is not it's native speed, you will need to increase voltage and loosen up timings, that is if you've already tested that it will run at those speeds stably. If you have been, you might just have reached the wall of your CPU or motherboard, though that 6750 should've reach 3.6 easily with proper cooling.

X2

Your power supply is just fine. I'd say your PSU is actully better than the average. You may just need to send more voltages to the cpu and memory. Your cpu and motherboard is plenty capable of hitting your goal. If upping the voltage doesn't work, I'd blame the memory.

[JSTpt1022]

Thanks for the help guys and the push in the right direction. As an update, I've been doing research and going about things more correctly now. I was a bit impatient before. Now I'm taking things carefully and slowly, stress testing at each level before moving on. I'm currently working on finding my lowest stable voltage at 3.2GHz, stress testing with Orthos. I still want to go higher but 3.2 really is an ideal level for my rig as it enables me to run my FSB and memory 1:1 without overclocking it. Alot of people have been running into walls of one form or another around 3.6 with the e6750 so that's my goal.

[TheMarchingMule]

Go to overclock.net if you need any more extensive forum-based help.

[skyline889]

Ahh, I forgot the E6750 had an 8x multiplier. I think the E6700 had the 9x multi. I'm running my E6600 at 3.6ghz with only 4x900 so 1:1 for DDR2 800 so I was wondering why you were having trouble. When Orthos testing, you want to run it for a long time. When I was testing my OCs, I had my system stable till like four hours so I thought they were fine but when I went back to test for longer durations, I had them fail after the four hour mark.