PSU limiting OC

Without saying more, because I don't want to tip my hand.. How can you tell if your PSU is limiting your clock?

Voices of experience only, please..

Heh. What I mean is, does raising my CPU/FSB/MCH voltages and clocks draw that much more power that it could cause the PSU not to be able to handle it? If so, what would the symptoms be?

ratbuddy said:

Heh. What I mean is, does raising my CPU/FSB/MCH voltages and clocks draw that much more power that it could cause the PSU not to be able to handle it? If so, what would the symptoms be?

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RB,

Overclocking will always draw more wattage as will a GPU card. The higher the OC, the more watts it takes. Depending on how close your PSU output is to your stock system needs, it's condition, and maker, I guess you could see limitations from overclocking simply due to no overhead left.

How much more power it draws may not be obvious to a layman without higher end test equipment. My CPU is default 110W and an estimate of my wattage consumption with my mild overclock is about 130-135W but I have no valid way to know for sure, its just a guess.

Of course my power supply's output is probably twice what I need so I wouldn't see any issues with any overclocks on my unit, even with a high end video card.

I would imagine some of the Intel Quad Core with a hot overclock may require quite a bit more from their default ~105W and the same with a hot video card. Combined, they may require another 100W from your PSU with hot overclocks on both. Since I have never had issues with not enough power from my PSU with overclocks, I would imagine freezes, random restarts, BSODs, shutdown, etc., could be symptoms of an overloaded PSU. Just a guess...........

ratbuddy said:

Heh. What I mean is, does raising my CPU/FSB/MCH voltages and clocks draw that much more power that it could cause the PSU not to be able to handle it? If so, what would the symptoms be?

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From my experience I would say absolutely. Symptoms would be excess heat from the psu, out of spec voltages or lower voltages or even voltage drops under load. Lower stable overclocks from what others are getting with comparable hardware.

Low quality psu's tend to have their rated wattage output at temps of 40c or even 30c, once the temps are exceeded the unit is running out of spec. and failure rates increase.

Quality psu's on the other hand generally output wattage ratings at higher temps like 50c.

Yup. So, buy a good one. Period.

If you just raise clocks and not voltage, does it still draw more power than stock clocks?

ratbuddy said:

If you just raise clocks and not voltage, does it still draw more power than stock clocks?

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Yes.

Symptoms would be excess heat from the psu, out of spec voltages or lower voltages or even voltage drops under load. Lower stable overclocks from what others are getting with comparable hardware.

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This nailed it. On my old Opteron rig I used OCCT to stress test and watch the voltages from the PSU. Before I upgraded to my HX520, I could see a notable drop on my 5v rail when I put the Opty to 100% load with a 25% OC.

Patient testing of each component, as well as looking for the above, will let you know that it's the PSU holding you back. If you know your parts can clock higher individually than they can when you OC them to those specs in unison, you probably have a power issue.