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View Full Version : Your opinion - Do I need 2 pumps?


edge929
12-06-07, 08:35 AM
I've run water for about a year now, still on my first custom built components:

MCP655
Apogee
Black Ice Pro 3
MCW30 (northbridge)
MCW60 (GPU)
See sig for everything else

Since I upgrade so often, I used an older case, gutted it and put all my main water cooling components in there and fed the tubing out from it to my main tower sitting right next to it. So the only thing in my main tower is the water blocks and tubing. This keeps me from moving around the main water cooling components every time I upgrade something. In total, I'm looking at about 12 feet of 1/2" clearflex. I've noticed my temps have risen when running Orthos by about 6C since I did it this way.

I've read that a long loop will worsen temps. Is this too long for a single MCP655?

Last question: Does the placement of the second pump matter? I'd like to keep it in the water cooling tower but it'll probably be chained right next to my first pump. I suppose ideally you'd want it halfway from the first pump but it's not a viable option for my setup. I'll try to post pics later.

[O-CuK]Marci
12-06-07, 10:09 AM
Single pump will cope fine with that lot.

That loop using 5ft of tubing = 1.7gpm est flowrate.
Using 10ft tubing = 1.67gpm est flowrate
Using 20ft tubing = 1.62gpm

Anything above 1gpm is considered good enough. Anything above 1.5gpm is considered spot on perfect. 2gpm and above, overkill.

See http://www.xtremesystems.org/forums/showthread.php?t=151627

Jas
12-06-07, 10:20 AM
Your single pump technically shoudl handle that loop just fine. Albeit you will loose some cooling potential over a loop say half the size, just because your loop is longer and is reducing flow.

Adding a second pump COULD lower temps. But that depends on how much heat you are already dumping into your Loop, and how well you can remove it. In your case, you shoudl be able to easily handle the extra heat dumped in by a second pump.

You have two choice as far as where to place the pump, inline, or parallel.

In line would increase head pressure allowing you to acheive a flow rate closer to the highest flow rate of a single pump.

Parallel would increase the flow rate, a side effect would be a head pressure increase.

Try out both methods, see what works best for your loop.

To do in line, you just dasy chain the pumps, parrele, use Y fitting to split the line to each pump, and then another Y to bring exausts lines back to the main line.

thideras
12-06-07, 10:30 AM
Your single pump technically shoudl handle that loop just fine. Albeit you will loose some cooling potential over a loop say half the size, just because your loop is longer and is reducing flow.

Adding a second pump COULD lower temps. But that depends on how much heat you are already dumping into your Loop, and how well you can remove it. In your case, you shoudl be able to easily handle the extra heat dumped in by a second pump.

You have two choice as far as where to place the pump, inline, or parallel.

In line would increase head pressure allowing you to acheive a flow rate closer to the highest flow rate of a single pump.

Parallel would increase the flow rate, a side effect would be a head pressure increase.

Try out both methods, see what works best for your loop.

To do in line, you just dasy chain the pumps, parrele, use Y fitting to split the line to each pump, and then another Y to bring exausts lines back to the main line.Yes, that is true it may lower temps, but you forgot to add in the heat dump from the pump. Is the heat added less than what you lose by running 1 pump?

Not worth the money or the hassle to add a second pump ;)

Jas
12-06-07, 10:37 AM
Yes, that is true it may lower temps, but you forgot to add in the heat dump from the pump. Is the heat added less than what you lose by running 1 pump?

Not worth the money or the hassle to add a second pump ;)


I took into account the heat from the second pump. He has a BIP 3, that is external, and drawing in clean air. He should be able to disapate the extra heat. That being said, I don't think he'll see a dramatic improvement, maybe a couple degrees.

If he wants a REALLY dramatic improvement, thrown in a secodn pump, and a second Rad. Which, for an external setup, isn't a bad option.

edge929
12-06-07, 10:48 AM
Thanks for all the advice guys. I appreciate it.

I do have room for another 120x3 or less radiator if I needed too. I am trying to get 3.6Ghz out of my 4300 but even with 1.62VCore with the Vdroop mod for my board (board max of 1.60), I still can't get it Orthos stable at those speeds. When I am able to bench that, I see temps in speedfan of ~70C with both cores at full load. I think we can all agree that's just too hot. As it is now, I'm seeing 66C at full load at 1.52 after 8 hours of Orthos. Lowering the Vcore anymore proves to be unstable.

In addition, I'm trying to OC my 8800GT to 750 core but I haven't gone in depth with that just yet. That should dump more heat into my loop than the CPU will at 3375mhz. Overall I suppose if I could get a hold of an additional pump and 120x2 rad, might not hurt. Thanks again for the comments.

thideras
12-06-07, 10:51 AM
Thanks for all the advice guys. I appreciate it.

I do have room for another 120x3 or less radiator if I needed too. I am trying to get 3.6Ghz out of my 4300 but even with 1.62VCore with the Vdroop mod for my board (board max of 1.60), I still can't get it Orthos stable at those speeds. When I am able to bench that, I see temps in speedfan of ~70C with both cores at full load. I think we can all agree that's just too hot. As it is now, I'm seeing 66C at full load at 1.52 after 8 hours of Orthos. Lowering the Vcore anymore proves to be unstable.

In addition, I'm trying to OC my 8800GT to 750 core but I haven't gone in depth with that just yet. That should dump more heat into my loop than the CPU will at 3.75Ghz. Overall I suppose if I could get a hold of an additional pump and 120x2 rad, might not hurt. Thanks again for the comments.If you have space for two radiators, just run two loops.

It will be easier to work with (if you have to break one down/work on one) and get better temps. ;)

Jas
12-06-07, 10:56 AM
If you have space for two radiators, just run two loops.

It will be easier to work with (if you have to break one down/work on one) and get better temps. ;)

I agree completely, isolate the CPU to one loop, then put the GPU NB on the other loop/