Water temp vs core temp - normal difference?

Hello,

Let me first off thank all of you for the wonderfull information that is availible in these forums. I have put together my first water cooling rig and have run into a question I have been unable to find searching through the web.

My water temp under full load runs somewhere around 33 deg C while the cores are running in the 48 deg C range. Is that a normal occurance? I had really expected the temps to equalize much closer than that. Here is what my loop consists of and in this order cooling an AMD 955 overclocked to 3.6gig:

Swiftech micro res
MCP 655 pump
Black Ice SR1 120.1
Black Ice Stealth 140.2
Swiftech Apogee XT

Is there something that I should be doing that I'm not at this point? The speed of the pump has very little effect on overall temps. I've re-seated my block to be sure that the grease was applied properly the first time and it looked like the first application was good.

Any thoughts or is this right about where I should be?

Welcome!

what are your ambient temps?

Water setups are generally judged on ambient air vs water temp delta.

a 15C delta is acceptable, but not near the best.
a 10C delta is about average
a 5C delta is great and anything below is excellent.

is that 48C load or idle? i'm not sure how amd's are, is that a high overclock for the 955?

From what I've read I'm on the low end of the 955's. People are able to get 3.8 without increasing the volts but I've had to up my CPU to 1.45 just to keep this stable at 3.6 - I can make it to 3.7 if I go all the way to 1.5v but thats just too hot for me to run 24/7. I use this for folding so I think I've taken her as far as she'll go for now.

I don't have a good feel for ambient (no real good thermometers) but I would say we were between 25C - 30C when I checked the temps of the water today.

I was under full load at the time running prime95 (various fft's). At idle my cores are at 36c right now, water is ... too low to register on the thermometer I'm using (fever type, lol) so I have no idea. According to the sensor in the case that's nearest the cool air, its 14.4C now but I have no idea if thats an accurate device.

Here's a pic of the install. It's still kind of flakey. I didnt' know what I needed in the way of elbows and tubing. I'm not real happy with the pump location at the moment... It's temporary until I can get the right fittings to route the tubes better.

to OCF!


I'd say your temps are pretty much in order considering your ambient temp. My OC'ed AMDs tend to run about 15°C or so above water temp so everything is fine there. Your water temp concerned me a little until I read you're in the 25-30°C range on ambients. Spawn-Inc's chart is spot on with that.

I do think there might be something you can do to get a little better OC from your 955, though. If you have the 955BE C2 then you'll have to work at it but a 955BE C3 should go to 4.0 on water without a problem. If you'd like to start an OC'ing thread in the AMD CPU section we can all take a look and maybe help ...

hehe.
U can see my loop in my sig. (using undervolted 3400rpm delta (5v)
All depends on water temps/ambient temps... pretty much
Here is some info I can give to you.
Okay.
U can see my water loop in sig.
Phenom II 955 c2 @ 3.8ghz and Vcore is at 1.25v
(currently stress testing)
My temps. 44degree load. --- everything in a 20-22 degree room (ambient temps)
Vcore at 1.45 temps was 47degree load

Just a piece of O/T advice; Check the res regularly. I removed mine after about 2 years in use because of (imo) too many cracks in the plastic itself. The res wasn't under any stress other then the hoses and mount, and although there were no cracks completely through the plastic, there were still many that continued to appear and get larger (deeper) in the plastic. I redid my loop with just a T-Line instead for peace of mind.

T-lines FTW ...!