CPU and G4 on separate paths?

should I put my CPU block and my G4 block in series or parallel? the G4 block has 3/8th inch fittings, and the CPU has 1/2. I have a maxi-Jet 1200 and an 89 camaro HC with 5/8ths tubing.

also, when I get a NB block, should I use it in series or parallel?

oh, the CPU will be first in all cases, the order will be pump/res-->HC-->CPU(and G4?)-->(NB)-->(G4?)-->pump/res.

the things in perenthesis I have yet to install, and my pump is submerged in my res.

No series, all seperate-much more better, obentosan...

I thought so, just wanted to make sure. thanks

Parallel is better as there is a lower resistance, but if you put the CPU and G4 block in parallel the G4 block will have a much smaller flowrate then the CPU block. If you have a NB block as well which is 3/8" then a good way would be putting the NB and G4 blocks in parallel after the CPU block.

So:

pump/res-->HC-->CPU-->(G4 + NB)-->pump/res.

This would be a good setup if you have a Cathar WW

I'm going to go against the grain in this thread and say that in series is better, mathematically speaking.

When you have them in parallel, you effectively halve the flow rate to each block.

When in series, it is more restrictive, but you'll never get as low as half the flow rate to each block as when you had them in parallel.

Why?

Because pressure resistance goes up quadratically in proportion to flow rate. Work the math through.

In series is better.

Let's back that up with a bit of theory.

Let's assume that we're using two waterblocks that are as "restrictive" as the White Water, and using a heater-core and an Eheim 1048 pump.

The Eheim 1048 can push 5.0lpm through a heater-core, and a single WW.

If we put two WW blocks in parallel, and working the math along with the Eheim 1048's PQ curve, we'd find that the total flow rate would be about 6.5lpm, or about 3.25lpm through each block.

If we put the two WW blocks in series, the total flow rate would be about 4.0lpm though each block after working the math.

Now since we know that a higher flow is better through the blocks, being in series makes more sense.

Could the higher resistance have an adverse effect on the operational life of the pump? At that high a flowrate, would it matter that you would get a marginal increase. Having a reliable flow rather than a fast flow would be better for my use, for example.

As you well know, the WW has 2 exit barbs. Linking one to a NB block and the other to a G4 block would mean you could use less piping. You wouldn't need a Y-connector then. Wouldn't that help reduce the resistance and therefore raise the flowrate?

Sidenote: Why would you need a relatively high flowrate through the Northbridge and GPU blocks? Wouldn't my idea work?

I can see why your suggestion would be the idea setup in a dual CPU system (citing your example) but with mixed chips giving out different rates of power would you want them all to have blocks on them all with the same flow? It seems a little unnecessary to me.

mathematically speaking.

Click to expand...

Cjwinnit said:

As you well know, the WW has 2 exit barbs. Linking one to a NB block and the other to a G4 block would mean you could use less piping. You wouldn't need a Y-connector then. Wouldn't that help reduce the resistance and therefore raise the flowrate?

Click to expand...

Hmmm, linking the two outlets to two separate blocks can impact the WW's performance, depending on how well matched those blocks are in terms of pressure resistance. If they are mismatched in even fairly moderate ways, this can disturb the flow distribution within the WW block. I personally wouldn't recommend doing so unless you have pretty much identical blocks on the GPU and NB.

Wow, quick response

Ok, I see the point. (paraphrasing) "Having the outlet holes have different flowrates may change how the block behaves". How tolerant is the block to asymmetric output flowrates? (I assume you are the Cathar, in which case great block )

Back to the original question, he didn't specify a particular block, only the system layout. A quick question: (you probably know more than I do )

Would putting the G4/NB blocks in parallel be a good idea for a weaker pump, bearing in mind the system above will need adaptors to go between 1/2" tubing and 3/4"?

Cjwinnit said:

Ok, I see the point. (paraphrasing) "Having the outlet holes have different flowrates may change how the block behaves". Is the block tolerant to asymmetric output flowrates? (I assume you are the Cathar, in which case great block )

Click to expand...

I was saying that it isn't that tolerant. Totally blocking off an outlet will cause about a 3C drop in cooling performance on a hot CPU. That's a completely asymmetric example. Whatever the actual asymmetric imbalance is will therefore result in a 0-3C drop in cooling performance.

Yes, 'tis I.

Cjwinnit said:

Would putting the G4/NB blocks in parallel be a good idea for a weaker pump, bearing in mind the system above will need adaptors to go between 1/2" tubing and 3/4"? [/B]

Click to expand...

Given a "standard" looking centrifugal pumping PQ (pressure/flow) curve, putting the blocks in series will be better, no matter the pump's strength.

However, if the NB/GPU are low heat devices (and most are) then it may pretty much be a non-issue, as ultimately we could be talking about 0.1C differences here between series/parallel, so it could be a case of "who cares?".

I'm just being pedantic about the theory though.