Will adding this 2nd heater core help or hurt me?

[Darkenreaper57]

Ok, here is my current setup:

Abit NF7-S
1 GB PC3200 cas 2.5 memory
athlon 2500+ (non-mobile)
geforce 4 4600

The equipment:
d-tek white-water cpu block
d-tek gpu block
77' Bonneville heater core w/custom plexi shroud 2'' standoff and 2 120mm fans
cheap tubing, i think its vinyl
eheim 1250
bay res

Ok, right now im at 215x11 and 1.85V (i can go higher, will do once i get a hs for SB cuz if I go too high my onboard sound distorts). My idling temps are about 41 C in a room that is 26 C. Case temp are upwards of 33-34C (i only have 3 case fans, 2 intake, 1 out).

Anyway, I would like to lower my temps more if possible, and I have a spare d-tek procore 120 lying around with a shroud and 120mm fan.

My question is, will adding this core to the loop after the cpu and before the gpu help or hurt things? I would think that it would help, but I am not sure whether or not this would be too restrictive. I thought I would ask you guys before I did anything.

I also ordered 4 case fans, I think they will help a lot.

On a side note, I hear that the NF7-S reads temps a bit high, so where can i get a nice cheap flat thermistor or probe that I could put between the waterblock and CPU? The cheapest thing I saw was 20 bucks, and i dont need a fancy digital readout.

Thanks.

[saratoga]

Two radiator's in parallel would have less flow restriction then one, so your CPU flow will actually increase.

[Darkenreaper57]

Are you sure about this? Sounds interesting and different. The only thing is...the two cores are different sizes...will this make an impact on anything if I run them in parallel? I assume I would do this with a couple y-connectors.

Also, since I would have higher flow in doing this, would my temps be lower as opposed to if I ran in series?

Thanks.

[nikhsub1]

I dont think adding the D-Tek core will do much, I would not run them in parallel as they are different, series would be the way to do it, which will hurt your flow with the 1250. Only way to tell is to try it and see, but really, I think it will not help performace as the bonneville is a good size rad.

[Gogeta]

What fans are you using on the heatercore? 38mm high pressure fans are the best for cooling down a heatercore.

You might also consider a more powerful pump to get your overall flow rate close to 2gpm.

[Darkenreaper57]

I am using 2 120mm fans. They are the common aluminum AOC Evercool fans that push 80CFM or so each. I currently have them attached to a rheostat so I can adjust the rpms (and the noise they create induced by that).

I made a plexi shroud with a 2'' standoff as recommended by weapon. The core sits completely external to my PC, on top with hoses running through the top (drilled a couple holes).

Anyway, whether I have the speed all the way up or down, it generally only has a 1-3C difference according to my in-socket thermistor under the cpu (yeah, I wish I could use the internal diode without doing some hardcore modding on this abit NF7-S. It is my only complaint about the board).

I plan on adding an inline water temperature sensor so I can judge whether the 2nd core will help or not.

[Gogeta]

80cfm is a lot for a standard case fan, but those Evercool fans aren't beefy enough to properly cool a dense heatercore. Delta makes several high pressure 120x120x38mm fans rated above 100cfm that should knock a few degrees off your idle, and definitely load temps. These fans don't whine either, they're very tolerable at stock volts and respond well to logical (ex. no 24v fan @ 5v) voltage adjustments.

http://www.delta.com.tw/products/dcfans/search_all.asp
http://www.delta.com.tw/products/dcfans/search1.asp

Try swapping fans before the extra rad :)

[Pha_Q]

about the parrallel / series deal, i'm almost 100% sure temps were better in a review i read when the 2 like heatercores were in series, not parallel, for some reason. i think it was because all the water gets cooled twice, instead of half the water going to 1 core, half to the other, make sense?

[nikhsub1]

Originally posted by Pha_Q
about the parrallel / series deal, i'm almost 100% sure temps were better in a review i read when the 2 like heatercores were in series, not parallel, for some reason. i think it was because all the water gets cooled twice, instead of half the water going to 1 core, half to the other, make sense?
No. That theory is not based on physics. You may well have seen better temps with like rads in series, Cathar gets better temps that way. Many factors play a part of which way is better. With different rads, I would never run parallel, with my 2 D-Tek cores i do run parallel. Anway, back to your theory, heat exchangers work best (most efficient) when the differential between water temp and air temp are high; ie the rad does a much better job at cooling 50C water in a 20C room that cooling 25C water in a 20C room. Now, rads in series; the SECOND rad is very inefficient as compared to the first. Why? Because the temp differential between water and air in rad 1 is greater than rad 2 since rad 1 has already cooled the water some. In parallel you don't get that, both rads are just as efficient.