Need help with a design

[learning curve]

2 pumps in series equals twice the pressure, and 2 pumps parellel equals twice the flow, if I'm not mistaken.

This is a msconception.2 pumps in series increases your flow rate. It would take 4 pumps to double your flow.

 

[Kemon]

Twice the power isn't specific enough.

2 pumps in series equals twice the pressure, and 2 pumps parellel equals twice the flow, if I'm not mistaken.

Ok that's kind of what i figured...

So i want twice the pressure then for my system? It'll be running to my CPU and then to my two graphics cards... so more pressure would let the fluid get all the way around the loop i'm assuming.

 

[billb]

So i want twice the pressure then for my system?

Don't do the nOOb thing and think that flow rate is king...turbulance is king! Which Storm block? turbulators or channeled pins?

Race car analogy: One mile oval, car goes 60 mph and another goes 120 mph. In a 10 minute time span each spends the same amount of time on the front stretch. So, no matter what the flow rate the water spends the same amount of time in the blocks and rad. I cool an FX57 and two 6800gt's, both OC'd pretty hard with an Eheim 1048 for daily use. For big OCs I kick on an Iwaki MD20RZT. The Iwaki puts about 2GPM at 3psi through the loop, the Eheim, about 0.5gpm and it doesent even move the pressure guage. For OC's I kick in the Iwaki and a second rad with 2 X 190 CFM fans..you couldn't live with that noise, but it will OC significantly higher. See http://forums.overclockers.com.au/showthread.php?t=441886&page=1&pp=15
SLI 6800 section

Fans don't work that way...CFM (actual CFMs through the rad, not the CFM rating of the fan(s)!) is king! But more CFM = more coolimg = more noise. See http://forums.procooling.com/vbb/showthread.php?t=12581&highlight=fan+testing
See the links in post #3, It's in french, but you can read the graphs or use Babblefish.

Soooo, it's best to decide if you want to WC for quiet/reliability or go for max OC, before you buy the parts.

 

[Kemon]

OK so now i have this so far...

2 of these water-blocks for the 7900 GTX's $124.95
http://www.dangerdenstore.com/product.php?productid=189&cat=0&page=1

This 3x Fan Radiator $59.95
http://www.dangerdenstore.com/product.php?productid=222&cat=81&page=1

The Swiftech Storm CPU water-block $84.95

2 Swiftech MCP350 Pumps $69.99

How does that look?

 

[TreeNode]

Kemon, take a look at the link in my sig for my computer. I used very similar parts (exact same blocks). Note about the audio card between the video cards, you have to get the low-profile screws that come with the maze4gpu blocks, if you call them you can custom order them for like $7. Planning your case is probably the biggest challenge, especially with SLI water cooled. You'll need a case to fit all the tubes, specifically the tube the exits the bottom block (DD-78). I had to Dremel my case a bit to get it to work. If you have any more questions, don't be afraid to ask!! I had a very similiar budget so I have experience.

 

[Kemon]

Very nice looking setup man and it does look like you have almost the exact same setup i'm going for.

I was planning on getting this case, what do you think? It's got a lot of space in it... should work good i think.

http://www.newegg.com/Product/Product.asp?Item=N82E16811112067

 

[Kemon]

You tree do you have aim or msn or something maybe we could talk tonight? Your setup is perfect cause it's exactly what i'm going to do... maybe you could help me with parts?

Also tree, how does that computer run? I'm trying to build an awesome gaming computer so let me kno whow that thing runs for you.

 

[thorilan]

Don't do the nOOb thing and think that flow rate is king...turbulance is king! Which Storm block? turbulators or channeled pins?

Race car analogy: One mile oval, car goes 60 mph and another goes 120 mph. In a 10 minute time span each spends the same amount of time on the front stretch. So, no matter what the flow rate the water spends the same amount of time in the blocks and rad. I cool an FX57 and two 6800gt's, both OC'd pretty hard with an Eheim 1048 for daily use. For big OCs I kick on an Iwaki MD20RZT. The Iwaki puts about 2GPM at 3psi through the loop, the Eheim, about 0.5gpm and it doesent even move the pressure guage. For OC's I kick in the Iwaki and a second rad with 2 X 190 CFM fans.

?

more flow is always better . turbulance means nothing if your dt drops to nothing and you can not generate turbulance without flow.
so im not sure what you are trying to demonstrate since you using the iwaki is higher flow because it has more head to overcome restriction .

if water is going to spend the same amount of time in the rad no matter what the flow ( this is correct ) then you still want water to flow faster because your ultimate goal is to remove heat which is achieved through the diference between your heat soarce and the coolant temp .
the wider the dt the better which can only be kept wide with flow( the faster the flow the wider the DT begats the wider the dt the more efficient)

 

[TreeNode]

FYI, I've also referred kemon to this thread:
http://www.ocforums.com/showthread.php?t=449249

 

[billb]

more flow is always better .

Exactly!
I didn't say that because I don't think the nOObs are going to be looking at C/W and p/q curves for their blocks and rads like we do...at least not until their second or third WC setup. It's kinda like the "Will this 1000gph pump blow the hoses off my blocks?" when it has a 1 ft head. Flow is not king, pressure + block/Rad design = turbulance = big dT!

 

[thorilan]

ah ok now i understand the context.