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Spontaneous Reboots


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Link to substantiate this?

 

IIRC, I posted a link to a site that outlines it in another thread but don't recall which thread. Basically, it outlines the requirements to meet the bronze, silver, gold, etc. 80+ ratings. It shows that PSU's are most most efficient, but a few % points, in the 50% area. If I can relocate it, I'll post it again.

 

This isn't the original link, but it's one to wikipedia that shows that PSU's must be 3% more efficient at 50% load than they are at 25% or 100% in order to get gold rating: http://en.wikipedia.org/wiki/80_PLUS

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Joe_Miner

I wouldn't be surprised by that. I was simply talking about the principle. In his case it may mean buying the lowest capacity PSU he can find.

 

I think it's more important is to size your power supply to handle the maximum expected/possible load in your design -- not the average load plus 50%. You need to calculate the Max possible load plus some safety factor, which is what Newegg does (though I think they're very conservative) -- the real concern is to be sure to meet your max load. 500W should be enough in this application.

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I think it's more important is to size your power supply to handle the maximum expected/possible load in your design -- not the average load plus 50%. You need to calculate the Max possible load plus some safety factor, which is what Newegg does (though I think they're very conservative) -- the real concern is to be sure to meet your max load. 500W should be enough in this application.

 

I would certainly do that calculation, but I suspect that, in most situations, shooting for the average of 50% will leave plenty of room for the maximum spikes that may occur from time to time. If you calculate that it won't then definitely go for a larger PSU. But, since his primary use case is data storage, I think the 50% guideline is a good one in this case.

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Joe_Miner

I would certainly do that calculation, but I suspect that, in most situations, shooting for the average of 50% will leave plenty of room for the maximum spikes that may occur from time to time. If you calculate that it won't then definitely go for a larger PSU. But, since his primary use case is data storage, I think the 50% guideline is a good one in this case.

 

No. Do what you like but that is not good practice to design to "average" load. Design to max possible/expected load. If you don't meet your max load your system will fail. In this case 500W is probably adequate.

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Not that I don't think the PSU is the problem. The PSU is the most likely cause of random reboots with no log entry. I just wanted add that it could be the CPU overheating.

 

A lot of motherboards (all newer ones) will shutoff or reboot if the CPU hits a thermal limit. I seen this on a PC where a user installed a new heat sink incorrectly. I had to remove the heat sink, clean with rubbing alcohol, reapply the thermal past, and reinstall the heat sink.

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I did that no more than 5 months ago on a system that had to be shipped. You will see the thermal error message at POST.

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I did that no more than 5 months ago on a system that had to be shipped. You will see the thermal error message at POST.

 

That would have been nice.

 

The only other strange one I can think of caused blue screens, so that wouldn't help.

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Blue Screens sounds like a driver issue. Can you boot into Safe Mode with Networking or just plain Safe Mode?

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I don't know where you're at with this, but one thing I would do is disable automatic restart on failure so you get a good look at the BSOD, if there is one.

 

I like the 1 memory stick at a time check.

 

You're original PSU sounds cheap. If you have another one, I'd swap that out for a test. Even if it's not bad, I don't think I'd stick with that PSU. I'd get the least expensive, name brand, 80-PLUS PSU you can find. No honkin' video card in there, right? Something in the 300W to 400W range will more than cover it.

 

Also, were you ever able to get into safe mode and do the transfer?

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Not that I don't think the PSU is the problem. The PSU is the most likely cause of random reboots with no log entry. I just wanted add that it could be the CPU overheating.

 

A lot of motherboards (all newer ones) will shutoff or reboot if the CPU hits a thermal limit. I seen this on a PC where a user installed a new heat sink incorrectly. I had to remove the heat sink, clean with rubbing alcohol, reapply the thermal past, and reinstall the heat sink.

 

My son once brought a friend's computer to me, saying it would boot for a few minutes then shut down; it was driving the guy crazy. I gave it the once-over, saw nothing out of line, so I pulled the CPU cooler. There was zero thermal paste! I had a Mythbusters moment; "Well there's your problem right there!" :D

 

I put in some paste, ran memtest86 on the PC overnight, and my son gave it back to his friend the next morning. It was hilarious.

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