Put in New PSU and now old OC settings won't work?

[franklin411]

I have an E6750 on a Gigabyte P35-DS3L w/ 4 GB CL4 PC2-6400 ram. I was able to overclock it easily to 3.2 GHz by upping the bus to 400, and I got my Corsair/Patriot DDR2 PC2-6400 CL4 memory to run at their rated speed by boosting the vdimm to +0.4. The rest I ran stock. Didn't have to touch any other settings, and it ran stable for two weeks. The temp never got above 95 deg F even when multitasking (watching a movie on my HDTV thru my video card, playing games, and having word processing/acrobat files open--all simultaneously).

Today I switched from a PC Power and Cooling 510W PSU to an Antec Earthwatts 500W PSU as a result of replacing my beaten up old case. I love the new PSU because it's whisper quiet. However, as soon as I switched power supplies the system became extremely unstable. Sometimes I couldn't even boot into Windows. I tried upping the core voltage incrementally to 1.4 and haven't been able to find a stable setting.

I'm not sure if I need to find the settings that work for my new PSU, or if I have a defective PSU. After a lot of playing around and hoping for a solution, I decided to drop everything back to stock to see if the system is still unstable. It seems to be working fine, so maybe I just need to play with it a bit more to get things back where I had them.

I realize that the PC Power and Cooling PSU is a quality unit, but I already sold it on ebay...too loud for me, and the Antec is whisper quiet. Is there really that much difference between power supplies that when I swap one 500 watt PSU for another, I'd have to drastically adjust every setting to achieve the same stability? If not, then maybe I have a defective power supply on my hands. Any help would be greatly appreciated. Thanks!

 

[sutahz]

I could sell you a rock thats wisper quiet... You can always ask the buyer if you can keep the PSU and eat the cost of ebay fee's. You can also order yourself a new PSU. I may be mistaken, but the EW500 isn't a quality PSU. Its for tree huggers running their celeron and integrated graphics. Everyone will ask you this: what is the +12V ratings on the rail(s) of your P&C PC PSU and your EW500 PSU? That may answer a few questions right there.
Lets say (i havent looked up your PSUs....) they have the same ratings on the 12V rail(s), then its a question of which has better regulation of said rail(s). You traded a great PSU for a mediocure PSU, such is life.

 

[DrMrLordX]

The Earthwatts is good considering how cheap it is, but it can't compare to a PC P&C unit. The Antec only has, what, 34a on the 12v rail? Granted, it may not be so much a power issue as a voltage/ripple one but who knows. Might be better to take this issue to the Power Supplies forum, OP.

 

[franklin411]

Actually, after reading reviews, I thought this PSU would be overkill. I was going to go with the Earthwatts 380, since my system doesn't seem to be that much of a hog. The spec on the PC Power and Cooling PSU was 40A on the 12v, and it's 34A on the Antec.

I ran it stock for about an hour and it seemed fine, so I reverted to the OC setting I had been using before (400 mhz bus, memory multiplier set to 2.0 to get 800 mhz DDR2 speed). However, I set the voltage and timing settings to auto. I'm using 2 sticks of Corsair XMS2 PC2-6400 CL4 (only rated at CL4 @ 2.1v) and 2 sticks of Patriot PC2-6400 CL4 (rated at CL4 @ 2.2v), and the whole reason I upgraded was because 800mhz CL4 ram had gotten cheap. Then I had to get a new mobo to run the new ram @ speed. Then I had to get a new processor because well, why just replace the mobo? Then I had to get a new case because...OK the case was a good idea because my old one got smashed up when UPS used it for a battering ram (yes I got reimbursed). So I've been kind of insistent on getting CL4 out of the ram.

Am I setting the Vdimm too high? I had it set to +.4 because I figured the stock voltage was 1.8v, so +.4 would give me 2.2v. However, the BIOS PC Health Monitor was giving me readings of 2.05v on the vdimm so I did try boosting it to 0.5 to get 2.2v in the PC Health Monitor. no dice...still wouldn't run. I have it running stable right now @ 3.2ghz OC PC2-6400 CL5.

 

[franklin411]

K, does anyone think the problem is the memory? It seems to be the most unstable when I'm trying to get the mem to run at 4-4-4-12, and I have two different sets off 2x1 gb ddr2-6400 CL4 ram installed. The Patriots are rated at 2.2v CL4, and the Corsair at 2.1v CL4. I ran Everest with both installed at 2.05v and immediately got a hardware failure notice on the memory test.

I pulled the Patriots and ran the system again (overclocked, using my old settings), and the memory tests fine.

I ran the system with both sets of memory installed at CL5 (both sets are rated at 1.8v CL5), and the memory tests fine.

 

[Mondoman]

I agree that it's likely poor voltage regulation or excess noise with the Earthwatts PS.