temps acceptable? (need input)

After a week of priming, i've gotten what i will consider my accepted load and idle cpu temps.

Note, my rig is a dually, and both WBs are on, but only one cpu atm.

Room temp: 28*C
Case temp: 35*C
CPU temp (idle): 42*C
CPU temp (load): 45*C

this is with my 2 rad fans at the lowest speed.
I am not too pleased with these results, seeing that my cpu is underclocked to ~1.8gHz. The WB is a Dtek TC-4 rev1, the pump is an MCP650, and the rad is a 240x120mm heatercore. All case fans are blowing out to compensate for the large influx at the radiator (i want roughly neurtal case pressure to minimize dust and cat fur collection).
The block is mounted with AS5, and the blocks are both well lapped.

Any tips on lowering these temps? or is this the best i will do in Florida in the summer?

Thanks,
David

i say a 3 degree difference from idle to load suggests you have a very nice contact between the cpu and wb. The temps seem like they could be a little high, but if you are reading those temps from mbm off the onboard diodes they could be off by as much as 10º from what i understand.

also, what coolant are u running? too much antifreeze lowers the waters thermal capacity. 10% is adequate imo.

is the heatercore sandwiched between 2 fans? if not, that can hurt. the hc is the only chance u get to spend the heat out of the water. the more airflow over it, the better. shrouds really help too. if u turn the fans all the way up what results do u get?

give us a little more info about your setup (i may have missed it in a previous post)

there is a shroud and i have ~10% antifreeze mixed with the water. I'll try to dig up some pictures of everything tomorrow.

We all worry about what your MBs report as far as temps go, but the fact that you have only 3c from idle to load means you are cooling well. From what I understand, going water can actually cause your MB sensor to read a little higher because it is not getting the airflow around the sensor area it once was. The idle to load is more what you need to be looking at.

I run air cooling and it's cooler than that. Those temps are a bit high.

That can not be right. . .i dont even think it is close. Compusa has temp readers for 10 dollars, pick one up and see what it comes out too on the reader.

I think his temps are OK and the 3C delta between idle-load is excellent.

I've had my watercooling setup on 3 different motherboards in 2 different cases. Two were Soltek Nforce2 mobos that read the temp diode within the CPU and the final setup is the current Abit NF7-S which has the cpu temp probe against the bottom of the cpu. All 3 mobos report(ed) cpu temps from the mid to high 40's with the cpu (and possibly gpu) loaded. My temps are going to read a little higher than most because I run 25% anti-freeze with distilled water and my rad only holds a single 120mm fan running at 5V.

The ultimate answer about temps is they are OK if your computer is stable under heavy load at your desired overclock level.

To improve temps, he could change out the TC-4 block(s) for something better and reduce temps by a few degrees, but is it worth the trouble if what he has works? The pump and rad are good components. Getting the coolest air possible to the rad will directly reduce CPU temps. Adding the second cpu probably won't change temps very much. It'd be worth experimenting with fan speed/airflow through the rad vs. cpu temps. Working up from really slow fan RPMs should show a continual reduction in temps then you should hit a point where more air doesn't seem to help much; that is the knee of the radiator performance curve for your situation. Slightly above that knee would be the most efficient point to run the fans if the noise level is acceptable there.

well, i just primed for 7 days with no hitches, so i image it's pretty stable. I know my blocks are a weak point, but if i put in something like an RBX i dont think i'll get sufficient flow through the second block since those RBXs are really high impedance. The location of my computer is also not ideal - it sits under a desk where it doesnt get the coolest air from the room.

I'll look into that temp probe. Where would i mount it btw? Would touching it to the block be sufficient?

Also, i'll try slowly turning up the fans. Now that i think about it, this rad is painted. Maybe the paint is reducing it's thermal conductivity.

Thanks for the constructive comments,
David

Forget the RBX or TDX, get a pair of swiftech MCW600x blocks. They don't require high flow rates to work well (I know that is herretical statement around here, but it is true). You've got plenty of pump pressure to drive 2 cpu blocks and a gpu block. I'd look really hard at using 3/8 ID tubing if you know you aren't going to get over 1-1.5 GPM flow rates; it is much more convenient to route than 1/2ID. What Swiftech offers is a good guide for practical watercooling. The exception might be using 1/2ID tubing for the pump inlet; low restriction there makes a difference.

Getting cool air to the rad will pay off greatly and should be a priority. Every degree drop in air temp to the rad will result in a corresponding temp drop at the CPUs. Maybe a fresh air duct would help.

If you have an exposed core CPU (You should) you can basically use some thermal tape to attach the temp sensor right up against the core. Put a small dab of thermal paste on the temp sensor, and angle it so it toughes the core, and will also make contact with the water block wonce it is mounted. Take your time and be delicate mounting the waterblock so you don't knock the sensor off. that shoudl give yuo a pretty accurate temp reading, generally within a degree or two.

i think if the rad was painted it could be effecting its performance. there are certain types of paint that dont effect thermal properties, but if it was sprayed with cheap spray paint or something i would bet its costing a few degrees. u should try and move as much (cool) air as humanly possible, just as an experiment, through the rad and see what temps u get. i have a single 120mm rad with 2 fans (103cfm) and i usually see temps in the upper 20's while im working (not full load). and i do not undervolt them, they run fast always. i dont have 2 blocks, but i have 1 cpu (main source of heat) like u. and i most certainly dont have great flow rates.

just some thoughts...

I agree, the temps are kinda high....I think you do have a flow prob