Not happy with temps under water setup

[CustomBuild]

Do you have the rad inside the case or outside? If inside, improve case airflow and flow across the rad. Also, I have found out that brand name rads are not as effective as heater cores. (How? Lots of observations from posts like yours)

 

Another thing, what pump are you using? You sure you got proper flow? What size lines? You might be either moving water too fast (not enough time to transfer) or too slow (heat saturation). No kinks on the lines? Air purged from the rad and TDX?

 

The rad is inside (front of the Stacker case), pulling room air in and through the rad. It does not appear to be airflow rated as I see no difference if I run the rad fans low, med, or high rpm (have them connected to a Sunbeam fan controler). Plus as Radodrill mentioned I doubled my rad size and did not see an impact.

 

I am using a D5 with 7/16 Masterkleer. Tubing is short, clean, and no kinks. I am running the D5 on the highest speed setting (5) so it can't be too slow. With a 2-pass 240 rad it is hard to believe that the flow could be too much, but I suppose it could be possible, specially with a CPU only loop. I will try different pump settings and see if that helps.

 

I can't swear that there is no air trapped somewhere in the rad or block. It is possible. It could take a number of days for any trapped air to be absorbed so I will have to wait and see on that.

 

Right now I tend to agree with Radodrill in that most likely it is a IHS to WB issue. For my luck it is posible the IHS is not flat. I have not convinced myself it is worth sanding/lapping yet. My temps are not bad, just a little higher than I had wanted.

[Curtybob]

I really ain't sure where this one came from :

 

Another thing, what pump are you using? You sure you got proper flow? What size lines? You might be either moving water too fast (not enough time to transfer)

 

I edited this because I'm a bonehead. I hope you mean the flow inside the radiator when you say that, and not the flow over the CPU block. I can understand if the idea is to cool the fluid off a little more, and slow it down in the radiator. But, as the rad's size has been doubled, this is most likely not the issue.

[CustomBuild]

Thanks for the ideas Politbureau.

 

1) It is possible my application is not good. When I changed nozzels I obviously had to remove the block. I noticed then that the spread was fairly even, slightly larger than a quarter, but was not transparent. It looked somewhat thick. While I am doing a "dab" in the middle, it is possible my dab is too big Although it could also be due to a concave IHS etc. I may reseat it and try using even a smaller dab.

 

2) My loop looks like that minus the res (I use a T-line). I was aware of the D5 heat dump so had the output going to the rad.

 

3) Right now, since I have fans on the outside of the rad pushing air through it, the fans are about 1/2 inch from the front grills. I figured this should ensure that most of the air pulled in is from outside, but the rad is not sealed to the case so it is possible (but not likely due to the amount of flow) some case air is getting pulled.

 

4) I had read that nozzel #4 tended to give better performance so that is why I switched to it. But again I did not see any improvement.

 

6) I also am using Zerex + de-ionized water (I did my homework). I targeted 95% water, 5% Zerex (1oz Zerex to 16oz water).

 

7) Now this could be an issue. I could have air trapped. I had a big problem with air bubbles/micro bubbles when I filled it. It usually takes hours to sort it way out. Lines look good now, but I could still have air in the rad. To the best of my knowledge water will absorb air over time (thats why pressure tanks need bladder/diaphram seperating the water from pressurized air) but it could be a function of pressure. I am hopeing that and air bubbles will get absorbed over time. What has been your experiance with air in the system?

 

Yep, very similar setup, yet your temps were lower.

 

I will probably pull the WB, try using less ceramique and see if that helps.

 

Of course all this is based on the readings from the on chip sensor. According to some info I have seen from AMD the specs on them could easily account for the differece I see in my temps vs others. If my sensor just happens to read 2-3C higher than actual that would account for it.

[General Septem]

Try going directly from the pump to the block. In the Danger Den YouTube videos they used the same pump (I'm pretty sure) but they still went right to the block. From what I hear, there's really not much of a difference temperature wise, and the extra pressure and flow may negate that. You might consider trying it.

[politbureau]

1) It is possible my application is not good. When I changed nozzels I obviously had to remove the block. I noticed then that the spread was fairly even, slightly larger than a quarter, but was not transparent. It looked somewhat thick. While I am doing a "dab" in the middle, it is possible my dab is too big Although it could also be due to a concave IHS etc. I may reseat it and try using even a smaller dab.

Yeah I would check your IHS for flatness. My Opty 165 had some minor concaveness. Pull the chip and hold a straight razor against it (the old school, wrist-slitting kind ), then hold it up to a light. If you see any light bleeding through from under the edge of the blade, you might consider lapping the IHS.

 

Other than that, your setup looks good. See if you can pull the radiator out and just shake it around, flip it over, etc to try and dislodge any bubbles without bleeding the system.

 

And yeah, you should be able to read the writing on the chip through the left-over TIM when removing the block.

 

G'luck

[radodrill]

I'm currently running ~92% H2O + ~*% Zerex.

 

Also, My loop is D5 --> CPU --> 80mm Rad -->GPU --> 160mm Rad --> Res -->D5

Current idle/load temps of 28/40 C @ 3.92GHz (P4 540J) ~24C ambient

IMO the heat added by the pump is very minimal and shouldn't make a difference in temps. The notion of placing the Rad after the pump originated in the early days of WCing when people often placed a garden pump into a water container as a pump/res combo; this results in the pump dumping heat into the water (rather than to the air as with inline pumps) requiring the rad to be installed after the pump to achieve low temps.

 

p.s. I've taken classes in Heat transfer.