Go Back   Pro/Forums > ProCooling Technical Discussions > General Liquid/Water Cooling Discussion
Password
Register FAQ Members List Calendar JavaChat Mark Forums Read

General Liquid/Water Cooling Discussion For discussion about Full Cooling System kits, or general cooling topics. Keep specific cooling items like pumps, radiators, etc... in their specific forums.

Reply
Thread Tools
Unread 09-15-2005, 09:35 PM   #1
Maviryk
Cooling Neophyte
 
Join Date: Sep 2005
Location: Michigan
Posts: 9
Default Flow and pressure in serial/parallel loops

Hey guys,

I am new to this forum. I've been watercooling for six months now, and my first computing forum was extremeoverclocking.com (ECOF). I joined it by mistake :shrug:

My roommate uses Folding@home for tom's hardware folding, but we use EO for their graphs and plots of finished computing. I thought I was joining Tom's Hardware Forums at the time.

Anyhow, I have a few questions.

The current watercooling setup I have is cooling a P4 3.2 E0 Prescott and an Nvidia 6800. For the CPU I am using the DangerDen TDX 3/8"ID fittings(at the time the Swiftech 6002 was out of stock) and GPU the ThermalTake Bigwater 1/4"ID fittings. My original setup used the Via Aqua 2600 pump and a 9"x6" heatercore. Initially my blocks were in serial, but that caused the impellor to create too much noise due too much head.

Since then my original pump has failed (outlet barb leaked due to overtorqing)and I am working on a new case. I'll be using a Hydor L30 pump with a Dual 120mm heatercore.

I would like my CPU to get the best flow, should the blocks be in parallel or serial? Is the loss of flow due to being in parallel greater than the loss due to the restrictiveness of the 1/4" ID size of the GPU blocks?
Maviryk is offline   Reply With Quote
Unread 09-16-2005, 05:38 AM   #2
Long Haired Git
Cooling Savant
 
Long Haired Git's Avatar
 
Join Date: Jan 2003
Location: Sydney, Oz
Posts: 336
Default

Approximator to the rescue!
I've used a MCW5002 as the GPU block. Don't have PQ for TT Bigwater, nor C/W. Anyone?
CPU = 70W and GPU = 30W.

Code:
Layout	Pump	W	Flow	Water C	CPU C	GPU C
Serial	Iwaki 30	30.9	9.46	4.9	17	11.18
Serial	Iwaki 20	12.8	8.08	4.37	16.6	10.65
Serial	D4	11.8	6.6	4.35	16.82	10.71
Serial	L30	15.6	5.25	4.58	17.34	11.03
Serial	MCP350	5.3	4.31	4.22	17.26	10.76
Parallel	Iwaki 30	32.89	15.75	3.65	16.18	9.1
Parallel	Iwaki 20	13.5	13.27	2.33	15.09	8.5
Parallel	D4	12.38	10.36	2.32	15.43	8.54
Parallel	L30	17.22	8.44	2.55	15.99	8.81
Parallel	MCP350	5.52	7.17	2.17	15.9	8.49
Now all of this below is plus/minus one trillion degrees because its all interpolated graphs and guesswork and it is combining testing results with different assumptions and bunch of other stuff that has BillA groaning and Les vomitting blood, and ScienceWiz slitting his wrists. Don't care, it gives a good guide as per above.
__________________
Long Haired Git
"Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford)
My Rig, in all its glory, can be seen best here
AMD XP1600 @ 1530 Mhz | Soyo Dragon + | 256 Mb PC2700 DDRAM | 2 x 40 Gb 7200rpm in Raid-0 | Maze 2, eheim 1250, dual heater cores! | Full specifications (PCDB)


Last edited by Long Haired Git; 09-16-2005 at 06:56 AM.
Long Haired Git is offline   Reply With Quote
Unread 09-16-2005, 06:02 AM   #3
bobo5195
Cooling Savant
 
Join Date: Aug 2005
Location: uk
Posts: 400
Default

xbitlabs indicates a 6800 is nearer 40watts
http://www.xbitlabs.com/articles/vid...v-power_4.html

I would think that it is far more helpful to calculate the prsure drop by analyitcal methods. I would of thought that the big water is a maze type block with loads of turns. I'll have a look at it this evening.

The 1/4 inch tube is going to make a huge difference isn't? Espeically the borda head loss in the y splittler.
bobo5195 is offline   Reply With Quote
Unread 09-16-2005, 01:23 PM   #4
bobo5195
Cooling Savant
 
Join Date: Aug 2005
Location: uk
Posts: 400
Default

tried to calculate the pressure drop in the gpu block form first principals but getting a high answer. Guesimating k=0.2

head loss from pipe fiction seems low (or order 2mm) but bends add shed loads of resistance.
bobo5195 is offline   Reply With Quote
Unread 09-16-2005, 02:43 PM   #5
Maviryk
Cooling Neophyte
 
Join Date: Sep 2005
Location: Michigan
Posts: 9

The GPU block is here http://www.xoxide.com/thermaltake-bi...ter-block.html

I made a different mounting bracket for it. First and last time I'm buying a cheap block.

Right now I'm running in parallel with the L30, load temps with 100% CPU and GPU (running World of Warcraft GPU/100% CPU/50% and Folding@Home CPU/50%) temps are CPU 44C, GPU 42C, Water 25C, intake air~20C

Idle Temps are CPU 29C, GPU 35C, Water 23C. +/- 1C on temps, using external probes for CPU, Air, and Water, Onboard for GPU.

Thanks for your help guys, just what I was looking forward to when joining the Procooling forums.

Here's a pic of my current temporary setup

Last edited by Maviryk; 09-16-2005 at 02:52 PM.
Maviryk is offline   Reply With Quote
Unread 09-16-2005, 04:55 PM   #6
billbartuska
Cooling Savant
 
Join Date: Jun 2005
Location: Skokie, Illinois
Posts: 322
Default

You're right. In series the 1/4" GPU block will restrict the flow to the CPU block. But, in parallel the 1/2" CPU block will get most of the water.

The solution isn't a bigger pump (though that almost always is a positive).

The solution is a new GPU block which will function efficiently (ie. cool the most) with the flows you anticipate with the new pump.

Ya kinda have to look at pump curves and block restriction curves and see where you're at and where you want to go. Don't forget to figure in pump losses for tubing, fittings, rad, and ras

As i see it, parallel/serial isn't the question.
Attached Images
File Type: jpg Ser Par.jpg (100.1 KB, 18 views)
__________________
My new rig....
Intel SE440BX-3, PIII 550 (@ 680)
MX440 275/332 (@ 350/400) and 3DFX Voodo 5 5500 160/160 (@180/180)
Two Opticals and 120 gigs (w/28gigs in RAID0) on 4 Maxstors
billbartuska is offline   Reply With Quote
Unread 09-16-2005, 05:03 PM   #7
Long Haired Git
Cooling Savant
 
Long Haired Git's Avatar
 
Join Date: Jan 2003
Location: Sydney, Oz
Posts: 336
Default

My figures our out because I forgot to add in the restriction caused by 3/8" fittings on the blocks and rad.

That said, something is wrong with my approximator. The water temp is either too high for serial or too low for parallel.

Sigh.
__________________
Long Haired Git
"Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford)
My Rig, in all its glory, can be seen best here
AMD XP1600 @ 1530 Mhz | Soyo Dragon + | 256 Mb PC2700 DDRAM | 2 x 40 Gb 7200rpm in Raid-0 | Maze 2, eheim 1250, dual heater cores! | Full specifications (PCDB)

Long Haired Git is offline   Reply With Quote
Unread 09-16-2005, 05:04 PM   #8
Maviryk
Cooling Neophyte
 
Join Date: Sep 2005
Location: Michigan
Posts: 9
Default

My radiator has 5/8" fittings. The 1/2" tubing is stretched over it.

It looks like I just might have to shell out $70 for a high flow GPU block, Perhaps the Dangerden Maze4? This was what I was trying to stay away from seeing as how I'm strapped for cash.

Last edited by Maviryk; 09-16-2005 at 05:10 PM.
Maviryk is offline   Reply With Quote
Unread 09-16-2005, 05:14 PM   #9
bobo5195
Cooling Savant
 
Join Date: Aug 2005
Location: uk
Posts: 400
Default

problem is that the gpu blocks restricitiness can not be easily analytically quantified. I attempted using pipe pressure drop equations (darcy with rectangular to cylinderical diameter correction, calculated re=2800 @ 1 lpm so used colebrook for a punt) but the bends in the block proved to be where the restrictivness came from. All gpu blocks are going to be like this as they are maze style and nobody has done any testing on them.

Rather than test doing seris with a big ass pump to remove any vagueness is a sensible approach that can't fail to produce satisfactory results.

Git (if i may call you that) have you considered that a) the block approximation you are using is wholy inaccurate and your calculator does not include bends in pipes which have a k factor of 0.19 per bend. Also all these tube connectors are bound to cause some kind of pressure drop.

Besides your approximator is approximate anyway and you can always blame crap mobo temprature sensors.
bobo5195 is offline   Reply With Quote
Unread 09-16-2005, 09:43 PM   #10
billbartuska
Cooling Savant
 
Join Date: Jun 2005
Location: Skokie, Illinois
Posts: 322
Default

http://overclockers.com/articles373/wbsum.asp
http://overclockers.com/articles373/basum.asp
__________________
My new rig....
Intel SE440BX-3, PIII 550 (@ 680)
MX440 275/332 (@ 350/400) and 3DFX Voodo 5 5500 160/160 (@180/180)
Two Opticals and 120 gigs (w/28gigs in RAID0) on 4 Maxstors
billbartuska is offline   Reply With Quote
Unread 09-17-2005, 03:24 AM   #11
Anonymous
Cooling Neophyte
 
Join Date: Jul 2003
Location: If only I knew...
Posts: 18
Default

Quote:
Originally Posted by Long Haired Git
Approximator to the rescue!
I've used a MCW5002 as the GPU block. Don't have PQ for TT Bigwater, nor C/W. Anyone?
CPU = 70W and GPU = 30W.

Code:
Layout	Pump	W	Flow	Water C	CPU C	GPU C
Serial	Iwaki 30	30.9	9.46	4.9	17	11.18
Serial	Iwaki 20	12.8	8.08	4.37	16.6	10.65
Serial	D4	11.8	6.6	4.35	16.82	10.71
Serial	L30	15.6	5.25	4.58	17.34	11.03
Serial	MCP350	5.3	4.31	4.22	17.26	10.76
Parallel	Iwaki 30	32.89	15.75	3.65	16.18	9.1
Parallel	Iwaki 20	13.5	13.27	2.33	15.09	8.5
Parallel	D4	12.38	10.36	2.32	15.43	8.54
Parallel	L30	17.22	8.44	2.55	15.99	8.81
Parallel	MCP350	5.52	7.17	2.17	15.9	8.49
Now all of this below is plus/minus one trillion degrees because its all interpolated graphs and guesswork and it is combining testing results with different assumptions and bunch of other stuff that has BillA groaning and Les vomitting blood, and ScienceWiz slitting his wrists. Don't care, it gives a good guide as per above.

Do you have TDX PQ data or are using another block for estimation?

Here's my guess for a series loop:
System1:
--TDX was derived from BillA WW data shifted to coincide with JoeC head loss data @ 1 GPM
--1.5 m straight 1/2" ID tubing
--MCW55 with 3/8" OD (~1/4" ID) fittings (assuming fittings from Swiftech data)
--77' Bonneville HC with 12.83" ID fittings ....slightly longer than a Caprice (~2"), but not much variation in head loss.

Too lazy for parallel data.
Attached Images
File Type: jpg untitled.jpg (119.4 KB, 14 views)
File Type: jpg untitled.jpg (118.0 KB, 9 views)

Last edited by Anonymous; 09-17-2005 at 03:37 AM.
Anonymous is offline   Reply With Quote
Unread 09-17-2005, 03:50 PM   #12
Long Haired Git
Cooling Savant
 
Long Haired Git's Avatar
 
Join Date: Jan 2003
Location: Sydney, Oz
Posts: 336
Default

Bingo - I just use BillA's testing results, and yes I used the LRR WW and not a RBX. Should of said so. I don't model blocks, but instead take measured results from other's testing. I can, however, model a conversion to 3/8" barbs pretty easy.

I would argue that the restrictiveness of the GPU block is what is keeping the CPU temps so good. Swap in a less restrictive GPU block, and more flow will be avoiding the CPU block and its temps will go up...
__________________
Long Haired Git
"Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford)
My Rig, in all its glory, can be seen best here
AMD XP1600 @ 1530 Mhz | Soyo Dragon + | 256 Mb PC2700 DDRAM | 2 x 40 Gb 7200rpm in Raid-0 | Maze 2, eheim 1250, dual heater cores! | Full specifications (PCDB)

Long Haired Git is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 01:53 AM.


Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
(C) 2005 ProCooling.com
If we in some way offend you, insult you or your people, screw your mom, beat up your dad, or poop on your porch... we're sorry... we were probably really drunk...
Oh and dont steal our content bitches! Don't give us a reason to pee in your open car window this summer...