Qs: single pass, dual pass, tri pass, with TEC'd CPU

[Mahmga5]

[Into]
Howdy, I am a newbie at water cooling, but not OCing and building PCs. I have many questions, a cold, and am reading prior posts, but am getting some mixed info (which might be me). I appreciate all feedback.

[Setup]
So, I put together a new water cool system as a tri-pass to the CPU, GPU, N/B as shown below using 4 Y-Fittings to split and join (2Y coupled=3 line splits):

. -------CPU (w/TEC)---
. | |
.From Pump---Rad-------GPU-------------Reservoir---
. | |
. -------N/B---------------

The CPU has a 226W TEC with seperate (mean well) PSU. The system worked quite nice, except for 2 problems:
1) The amount of 1/2" tubing and tight turns was cramping my style and cramping the case, and the tubing was pinching some all over.
2) The flow on the GPU and N/B seemed low - likely due to the double Y split and due to #1 above. However, overall flow was a jet of water into the reservoir.

I know ohms law applies to water flow and a parrallel version should have better flow rate, in addition supplying the best cooled water from the rad to each of the 3 waterblocks really made sense to me.

But, I wasn't satisfied, I have a cold atm, and decided it made sense to rip out the hosing and implement it in serial to decrease the cramped case and amount of tubing, which is now setup as:

From Pump---Rad---CPU (w/TEC)---N/N---GPU---Reservoir
Incidentally, the CPU gets down to 4.2C and stabilizes at 8.6C no load and not OCd (measured from back of CPU).

Now, my problem is 2 fold:
1) Because of this damn cold I was totally a loser and disregarded the immense heat coming off the CPU/TEC going into the N/B and GPU. The GPU and N/B are running too hot. This is not acceptable.
2) the water flow is lower, even with less tubing. Which I figured would happen, eg Ohms law & increased resistance. I can live with this, it is a 320 GPH pump, and 43" of tubing and is still a mini jet into the reservoir.

QUESTION:
What do you guys recommend for optimal (or decent solution), I figure I have 3 options:
1) Put the CPU/TEC last on the chain after the GPU & N/B. (which seems like a DUH! also would remove another ~6-10" of tubing.)
2) Redo this as a dual-pass - would *prefer* to avoid this again because of the amount of increased tubing in the case, and maneuvering around - Even with only 2 Y-fittings in this scenario, it is likely too cramped for my "taste".
3) Go for the full monty and implement inline water chilling (either via water chiller core, or inline 2nd TEC cold side against waterblock)?
4) Other ideas? 2nd Rad?

QUESTION:
When I ordered parts, I made a quickly discovered mistake on the radiator - I got black ice pro, not black ice xtreme. Should I bite the bullet and get the BIX? Is 919Wh vs 418Wh really going to make such a huge diff, again the the thickness of the BIX I want to avoid?

QUESTION:
I have only a 120mm 90cfm fan blowing on the rad (and 2 80mm case exhaust fans, but the case door has not been put on at any time yet), should I have another 120mm 90cfm as exhaust on the rad? I am assuming the answer is yes to this. Also, anyone have approx. #s as to the increased benefit of rad exhaust fan?

QUESTION:
What kind of temps should I be getting on the GPU and N/B? I haven't bothered to measure them. GPU is Radeon 9700 Pro, N/B off Epox 8RDA+.

QUESTION:
I have looked hard to find info on recommended reservoir (expansion tank) levels. 50%, 75%? If using a reservoir with the returning water inlet at midheight, should the water level be above or below this inlet?

Again, any info, thoughts, or links is all good and appreciated. I am trying to answer my own Qs.

[cloasters]

Welcome to AOA Forums, Mahmga5!

Bump. This post deserves answers! (Sorry, I know diddly about H2O cooling.)

[Random Nonsense]

Lots of questions there!

I would go dual pass if possible. use 1/2" tube on the CPU and 3/8 on the GPU and NB this way you get a higher flow where its needed.

As to the fans on the radiator, it would help but fact is I'd NEVER put that much heat into a black ice. They just arent really up to it! especially for the price! Im pumping in about 180watts into two polo heatercores. Very VERY effective and cheap to boot.

Watercooled, the GPU and N/B shouldnt really be more than a few degrees above ambient. My passively cooled 760MPX chipset only goes 2 c above case temp, and the 760mpx is a fairly warm chipset.

In revision to my spodes abode article: If the inlet into the reservoir is below the waterline you are running zero lift unless it is only trickling back down thanks to gravity. which in your case its not. So as long as the outlet is below the waterline its fine (also stops any splashes and bubble injestion into pump).

Expansion chambre volume. To be honest it doesnt matter. The temperature variation within the system will be reletively small, meaning expansion is also low. just a half inch gap at the top of the tank will do.

Welcome to the forums by the way

[Holst]

QUESTION:
What do you guys recommend for optimal (or decent solution), I figure I have 3 options:
1) Put the CPU/TEC last on the chain after the GPU & N/B. (which seems like a DUH! also would remove another ~6-10" of tubing.)
2) Redo this as a dual-pass - would *prefer* to avoid this again because of the amount of increased tubing in the case, and maneuvering around - Even with only 2 Y-fittings in this scenario, it is likely too cramped for my "taste".
3) Go for the full monty and implement inline water chilling (either via water chiller core, or inline 2nd TEC cold side against waterblock)?
4) Other ideas? 2nd Rad?

Put the rads in paralell, this will give higher flow and wont affect rad performance (this is only providing you get even flow, you may have to add valves if your rads are different to ensure water flow through each unit)

Through the TEC block you want max flow...
This is the most important thing, and you should try your best to maintain this.

If your NB and GPU blocks are high restriction go for a paralell system. If they are low flow then put the NB and GPU blocks in parallell then the CPU block inline.

So you have
............... / ¬¬¬¬¬RAD¬¬¬\........./------GPU----NB---\
PUMP-----/----------RAD-------------/ \-------Return
.............. \ / ....... \_____CPU______/
............... \ --------RAD------/

OR
............... /----RAD----\
PUMP-----/-----RAD----/--------CPU-----/----GPU----\-------Return
............... \------RAD---/..................... \----NB-----/

I think the second will be best.
If your having tubing troubles you may be able to drop to 3/8" tube on the rads and still get good flow... as your trippling up.

Waterchillers with TEC's just dont work, there pointless IMO, if your thinking of a waterchiller go for a old freezer and use phasechange.

QUESTION:
When I ordered parts, I made a quickly discovered mistake on the radiator - I got black ice pro, not black ice xtreme. Should I bite the bullet and get the BIX? Is 919Wh vs 418Wh really going to make such a huge diff, again the the thickness of the BIX I want to avoid?

Using a TEC and NB and GPU blocks is gona mean big wattage, you will need allot of rad, or allot of air, preferably both..

QUESTION:
I have only a 120mm 90cfm fan blowing on the rad (and 2 80mm case exhaust fans, but the case door has not been put on at any time yet), should I have another 120mm 90cfm as exhaust on the rad? I am assuming the answer is yes to this. Also, anyone have approx. #s as to the increased benefit of rad exhaust fan?


I run dual pushing and pulling fans on my rad, it helps allot and lets me run lower voltages and maintain airflow.


QUESTION:
What kind of temps should I be getting on the GPU and N/B? I haven't bothered to measure them. GPU is Radeon 9700 Pro, N/B off Epox 8RDA+.

ive no idea... i get good stability with 30*c water on my 8RDA+ northbridge at 225fsb 1.85v VDD, so you can get the nB warm without problems..

As for the 9700 mine is still aircooled.

QUESTION:
I have looked hard to find info on recommended reservoir (expansion tank) levels. 50%, 75%? If using a reservoir with the returning water inlet at midheight, should the water level be above or below this inlet?

If you keep your inlets and outlets below the waterline then you wont have to refill the system once you start up and your system will for the most part bleed out any air itself.

[Mahmga5]

I know that was a lot of questions - in hindsight, I thought it would be overwhelming. I thank you guys both for responses, the information is exactly what I was looking for.

I am busy and will hopefully get to doing this work fri & the weekend. I will try to post later with my plan based on this info.