New loop - disappointing temps

[Fresh Daemon]

tl;dr
2500K at stock clock/volts has a load temp of about 28C over ambient. Loop is a Cuplex Kryos Delrin, Swiftech MCP35X, PA120.3 w/3 Yate-Loon D12SM-12s. Rad is external. Loop has been bled and run for about 2 weeks, waterblock has been remounted, tried more/less mounting pressure w/no change, TIM contact patch looks fine. Is this normal or a problem?

Long version
I went back to watercooling after many years on air - my last water-cooled rig was an AMD Opteron with GTX 6800s in SLI.

I have a 2500K on an Asus P8Z68-V PRO. It's under a Cuplex Kryos Delrin. Pump is a Swiftech MCP35X, radiator is a PA120.3 with 3x Yate-Loon D12SM-12's (1650RPM) pulling through the rad. At the moment the rad is outside the case. Case is a Corsair 600T - I temporarily sat it on a radbox over the top grill, but I'm planning on getting a better case for an internal mount and cooling the GPU later. For now it's just the CPU, and the PA120.3 is almost certainly overpowered for a CPU-only loop - yet the temps seem rather high. In fact, they're only a few degrees lower than they were under the TRUE that preceded it.

At stock speeds and voltages, the CPU cores idle at 30/38/38/30 (cores 1 and 4 often fluctuate between 30 and 38 in less than a second with no graduation in between, which is weird - the temps on my last loop were really stable and climbed slowly even changing from idle to full load). Ambient is 28, so I guess the average core temp is 6 degrees over ambient, which isn't bad. Measuring with CoreTemp 0.99.8. RealTemp 3.70 doesn't disagree by more than a degree or two.

Under load, they go up to 51/61/61/51. That's an average of 56 degrees, which is 28 degrees over ambient, which seems very hot for stock volts and temps with this much radiator power.

I thought it might be the mount as the Cuplex has a really crappy mounting system, but a remount didn't do anything. TIM contact patch looked good. Also, since there's no way to gauge the "correct" pressure with its mounting system, I noticed the CPU socket area was noticeably bowed on the back of the motherboard; I backed off a little on the mounting pressure but that did nothing either. I have no way to measure the water temp, but I notice after an hour or two of BF3 that the radiator and the air coming out of it are noticeably warm, so there must be good contact between the waterblock and the CPU - right?

I shook all the air I could out of the loop during bleeding and leak-testing. The CPU block was harder to bleed, but I think I got it all. The loop has been up and running for two weeks now, so you'd think any small air pockets would have worked their way out by now.

Any ideas? I'm considering changing CPU blocks to something like the Apogee HD, with it's better mounting system, but I don't want to overlook anything. Or do these chips just run that hot? I don't have any experience with them - last CPU was a Wolfdale that ran way cooler.

[Utnorris]

What type of load are you talking about? Prime95, those temps are about right. Gaming, those temps are high. The new block might get you a few degrees, but I doubt that much unless the mounting is just way off, but it doesn't seem to be if you are getting a good spread of the TIM. If your load temps are from something like Prime95, then don't worry about it.

[Fresh Daemon]

Thanks for your quick reply! Those load temps are with OCCT. Prime95 actually loads up around 2 degrees cooler.

I was expecting something like my Opteron/6800 SLI setup, which even on a BIP3 had load temps probably 20+ degrees less. Sure, the CPU runs hotter - but the GPUs are out of the loop and the rad is better too.

[musicfan]

Those temps won't cause any problems. If you wish to try an inexpensive test, you could put your fans in push and see if it helps. The RPM is borderline speed to try to predict.

If you want a cheap way to check water temp, you can use an infra-red thermometer from a hardware store and check tubing and reservoir temps. Because of reflective error on most thermometers, you will want many samples. But when I checked my water temp directly (unscrew top plug from res) versus through res, they are the same so it will work. Good luck.

[spitter3]

Did you buy your block used, sounds to me like your block might have some foriegn dibri in it. A simple cpu loop should not be that hard to bleed.

[Fresh Daemon]

Musicfan: These are helpful suggestions. I could try switching the fans to push - I'll give that a shot when I have some free time, see if temps improve at all. I could also try a shroud of some kind.

I think the water temp is OK - if the CPU is under load for a long time, the radiator itself and the exhaust air feel warm to my hand (even in a 28-30C ambient room). However, that's a pretty vague "test" and an inexpensive IR thermometer might be useful. I'll look into that.

Spitter: No, the block was new. However, I rigged up a kitchen-faucet-to-1/2"-barb adapter with a bunch of parts from the hardware store, connected the block inlet to the faucet and blasted hot water at household pressure through it for 20 minutes. That should have cleaned any gunk out. It was enough to pop the tubing off the barbs in about 10 seconds without hose clamps.

[spitter3]

[QUOTE=Fresh Daemon;5112759]Musicfan: These are helpful suggestions. I could try switching the fans to push - I'll give that a shot when I have some free time, see if temps improve at all. I could also try a shroud of some kind.

I think the water temp is OK - if the CPU is under load for a long time, the radiator itself and the exhaust air feel warm to my hand (even in a 28-30C ambient room). However, that's a pretty vague "test" and an inexpensive IR thermometer might be useful. I'll look into that.

Spitter: No, the block was new. However, I rigged up a kitchen-faucet-to-1/2"-barb adapter with a bunch of parts from the hardware store, connected the block inlet to the faucet and blasted hot water at household pressure through it for 20 minutes. That should have cleaned any gunk out. It was enough to pop the tubing off the barbs in about 10 seconds without hose clamps.[/QUOTE]

Thats never a good idea, house water pressure can be 5-8x the pressure we normally run thru a water loop, and the block you bought has an o ring for an impingement device, you might have bent the micro pins under the o ring and damaged the block.

[Fresh Daemon]

I've never heard of such a thing. Do you know any actual incidents of that? The pressure isn't that high. Maybe if you blocked the outlets you might blow out the o-ring... but I've never heard of damaging the machining on the block itself. There was absolutely no damage to the block after I flushed it - I checked.

Besides, if it's good enough for Martin, it's good enough for me.

[spitter3]

I've never heard of such a thing. Do you know any actual incidents of that? The pressure isn't that high. Maybe if you blocked the outlets you might blow out the o-ring... but I've never heard of damaging the machining on the block itself. There was absolutely no damage to the block after I flushed it - I checked.

Besides, if it's good enough for Martin, it's good enough for me.

Household water pressure can exceed 50psi, this is more than enough pressure to cause permanent damage to radiators or blocks if you blocked the outlet port or ran the flow up too high. I personally have never had a problem with this, but I have heard at least one story where someone blocked the outlet port on a radiator and bulged the flat tubes out round

Glade you checked, I do have a rad with one tube balloned out by water pressure. Still use it.

[Fresh Daemon]

So the consensus is those are pretty typical temps for that sort of setup? OK.

[spitter3]

I think you are a little high for your rad size and fan speed, my 2600k at stock speed hits 51c at full load on the high core, Black Ice gtx240 with fans turning at 1000rpm, ambeint 22c.

[MrBean]

Those temps are fine, and very well within the lower part of the specifications, loaded that is. OCCT is anyway a very unhealthy test for your CPU, and you will never in real life induce similar loads on your CPU.

The problem we are facing with ever shrinking die-technology, is getting the heat out of the denser and smaller area.

But, as stated above, your system is fine, and I would only use the BIOS-Temps as an informative guide, not an accurate measurement - you cannot even accurately compare 2 similar systems.

Be happy, and enjoy your setup, should give you many years of trouble-free computing - if you stay away from lengthy OCCT/IBT sessions, that is