Cooling 240mm AIO CPU Cooler Expected TDP capacity

Hi,
What cooling capacity should I expect from a 240mm AIO CPU Cooler, for example an H100?

Background:

I'm having a bit of fun with overclocking, I've got an P9X79LE mb and a 3930k proc.
I've been following the ASUS youtube x79 overclocking videos, but to 4.5GHz and a VCORE of 1.35 volts and it overheats and throttles under prime95.

I replaced the old H100 with a Frostflow 240L, because the H100 is a reconditioned unit and I though it might be past it, and I've gone through a variety of fans. I think the heatsink is seated ok and I'm using gc-extreme tim. I have a additional large fan blowing onto the VRMs.

I'm running Linux but the intel turbostat utilities work and the package power is 230W+under prime95. The Package temperature gradually climbs until the thermal throttling kicks in.

So I'm wondering if a 240mm AIO cooler is sufficient.

Any suggestions?

 

It was about 82-85 degrees, but now I've got bigger problems. I was fitting a fan at the back of the mb as the back plate was really hot, and now the cpu wont post. The cpu light comes on and stays on. Not sure what I did. I guess I need to take the whole thing apart and carefully put it back together. I'm hoping I've not bust it.

 

A good 240mm AIO should easily be able to handle the temp of an overclocked 3930K. I've run many of the 1366 hexcores with a simple 120mm air cooler and have managed on several occasions to get 4.5GHz stable, and with the 990X I was able to get 4.7GHz stable (which needed over 1.4v).

I can't comment on 240mm AIOs because I've never used them before, but my brief experience with a 280mm AIO was very positive - my X5650 barely broke a sweat at 4.3GHz / 1.4v, barely reaching 65C under full load iirc.

Either you're unlucky and have got a really hot CPU (some do run excessively hot), or something else is causing it to get hot. I don't think you've borked it, certainly not with such low voltage.

 

4.5ghz is very high for a 3930k. On a h110 I got 4.7 out of a 3970x and heat stopped me keeping it at 4.9.

However most 3930k I see are usually around 4.2-4.3 on a 240 AIO. 4.5 would have to be a really good chip.

 

Really? That's weird. When I helped my mate build his PC a few years back he had his 3930K at 4.7 on a H100i with no probs and I didn't think anything of it. The main use of all that power was crunching 3D renders, so not a light load by any means.

 

Should I expect a cooler same overclock on a 3960X compared to a 3930k or is it a bit random?

 

Yeah man that's very high for a 3930k. Remember - these are six core Sandys, so you never got the same sorts of clocks that the 2500k and 2600k did. That was why they introduced the 3960x and 3970x as they were binned and somewhat guaranteed to run at 4.6.

Getting those sorts of clocks out of a hex core was very impressive.

You're sort of guaranteed 4.5 on those really, providing you have the cooling. My 3970x was nuts, though at 4.9ghz (it booted at 5.3 !) it proved too much for a 280mm AIO. I suspect I would have needed at least a triple rad water set up to maintain that, but in the end my motherboard died.

I used to test with Asus Realbench, and at 4.9 it was right on the limits of shutting down.

 

Well the original mb, is still poorly, with its intermittent ATX connection issues. I've put that on the backburner, and obtained a Gigabyte GA-X79-UD3 and a xeon 1650 v1 at a reasonable price.
Both work well together I'm getting ok temps (so far) at 4.5Ghz. It seems that I've been operating at around the limits of a standard 240 aic cooler which appears to be in the range of 200W with a great deal of variability dependent of fans, fan speed and radiator thickness. Still for now 100W per 120mm seems a reasonable rule of thumb.