Poll: Series or Parallel?

Hi Again.

I was reading the little "Water Cooling Q & A" and the Series Parallel section made little sense.

When in series the water block at the end of the line gets shafted... all the heat from the previous elements have already been introduced.

If you have a decent pump it seems like parallel operation would be the best option, hands down.

A parallel configuration should lower resistance of the setup (more water should flow from the pump... and possibly through each water block) But the biggest benefit would seem to be that each waterblock has the same tempurature water entering them.

So here is a Poll.... who uses series and who uses parallel?

Im almost postive 90% of the people use serial setups due to the fact they dont restrict flow such as using a split system.
It has been tested again and again that the temp difference is not worth the flow rate drop.

The Spyder said:

Im almost postive 90% of the people use parallel setups due to the fact they dont restrict flow such as using a split system.
It has been tested again and again that the temp difference is not worth the flow rate drop.

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Isn't temp difference the only deciding factor? Who cares about flow rate if your temps are lower?

squeakygeek said:

Isn't temp difference the only deciding factor? Who cares about flow rate if your temps are lower?

Click to expand...

True, very true. Since87 has some graphs he plotted out with various pumps/blocks/rads with the blocks in series and parallel. As far as the second block getting the shaft, not really as the water after the CPU block is at most 1/2 degree C hotter than just out of the rad, more likely .3C or so, not a measureable difference really. A parallel setup will yeild a higher OVERALL system flowrate, however, in most WB's the flowrate will be higher within the blocks in a series setup. The series setup will have a lower OVERALL flowrate. IMO series is the way to run blocks.

Im almost postive 90% of the people use parallel setups due to the fact they dont restrict flow such as using a split system.
It has been tested again and again that the temp difference is not worth the flow rate drop.

Click to expand...

Do you mean most people use series? Series is when they are all connected in one line. To me this seems like it would reduce the flowrate....

Higher flow rates have been able to acheive the same temps as Y based systems, of coruse this is based on the type of waterblock one uses. A cather WW for example works with all flow rates basicly, but higher yeilds lower temperatures. Thus having the block in serial would most likely give you same, if not better raitings if coupled with a GPU and NB block. Mind you no matter what you are adding the SAME amount of heat to the system that the radiator has to disipate.

MrMOSFET said:

Do you mean most people use series? Series is when they are all connected in one line. To me this seems like it would reduce the flowrate....

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Akk got my terms switched around, thats what I get for being gone for 8 months...

nikhsub1 said:

As far as the second block getting the shaft, not really as the water after the CPU block is at most 1/2 degree C hotter than just out of the rad, more likely .3C or so, not a measureable difference really. A parallel setup will yeild a higher OVERALL system flowrate, however, in most WB's the flowrate will be higher within the blocks in a series setup. The series setup will have a lower OVERALL flowrate. IMO series is the way to run blocks.

Click to expand...

That makes sense. Now lets assume you cool your video card with TEC. Would you put that as the last device in the chain or put it on it's own leg?

I can see what you mean... assume you have two devices A & B in parallel config. If A has a much higher resistance than device B then device A will get very little water and device B will get more than it needs.

Maybe I will try both just for kicks. Series is certainly less hardware and easier to connect.

MrMOSFET said:

...Now lets assume you cool your video card with TEC. Would you put that as the last device in the chain or put it on it's own leg?

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I would just make it the last device in the loop.

If I were running a TEC in a system where I wanted the cpu to stay cool, I would run the blocks in a series, but run 2 radiators, or 1 large one to reduce the large amount of heat a TEC dumps into the chain.

(Sorry im trying to type fast, the power keeps going on and off)

I use series and my temperatures are great !! link

WBs in series, rads in parallel, nuff said.

Series.

Here's a data table from Bill Adams showing the water temp rise after a waterblock to back up what nikhsub1 said.

load W . . flow . . . die T . . bp T . . inlet T . outlet T . C/W . . Btus*. . Watts . %eff
45.00 . .2.0/7.57 . . 36.5 . . 27.1 . . 25.00 . . 25.08 . . 0.256 . . 144 . . . 42.2 . . 94
45.01 . .1.5/5.68 . . 36.7 . . 27.3 . . 25.00 . . 25.11 . . 0.260 . . 148 . . . 43.4 . . 96
45.01 . .1.0/3.79 . . 37.2 . . 27.7 . . 25.00 . . 25.17 . . 0.271 . . 153 . . . 44.8 . . 99
45.01 . .0.5/1.89 . . 38.2 . . 28.7 . . 25.00 . . 25.33 . . 0.293 . . 148 . . . 43.4 . . 94

75.02 . .2.0/7.57 . . 45.0 . . 29.4 . . 25.00 . . 25.14 . . 0.267 . . 234 . . . 68.6 . . 91
75.02 . .1.5/5.68 . . 45.4 . . 29.8 . . 25.00 . . 25.18 . . 0.272 . . 243 . . . 71.2 . . 95
75.02 . .1.0/3.79 . . 46.1 . . 30.4 . . 25.00 . . 25.28 . . 0.281 . . 251 . . . 73.6 . . 98
75.02 . .0.5/1.89 . . 47.8 . . 32.0 . . 25.00 . . 25.56 . . 0.304 . . 251 . . . 73.6 . . 98

105.04 .2.0/7.57 . . 53.3 . . 31.6 . . 25.00 . . 25.19 . . 0.269 . . 341 . . . 99.9 . . 95
105.04 .1.5/5.68 . . 53.9 . . 32.1 . . 25.00 . . 25.26 . . 0.275 . . 350 . . . 102.6 . . 98
105.04 .1.0/3.79 . . xxxx . . 33.0 . . 25.00 . . 25.39 . . xxxxx . . 350 . . . 102.6 . . 98
105.04 .0.5/1.89 . . 56.9 . . 35.2 . . 25.00 . . 25.77 . . 0.304 . . 346 . . . 101.4 . . 97

Colin, I assume that "inlet T" and "outlet T" are the inlet and outlet water temps for the waterblock, but what are the "die T" and "bp T" (CPU temps maybe) ??

Higher flow rates have been able to acheive the same temps as Y based systems, of coruse this is based on the type of waterblock one uses. A cather WW for example works with all flow rates basicly, but higher yeilds lower temperatures. Thus having the block in serial would most likely give you same, if not better raitings if coupled with a GPU and NB block. Mind you no matter what you are adding the SAME amount of heat to the system that the radiator has to disipate.

Click to expand...

That makes sense. What about this idea...if you're cooling your GPU, CPU, and NB, would it be a better idea to run the NB and GPU in parallel after the CPU? My reasoning is this...

The NB (and GPU too) are going to be more restrictive than the CPU waterblock. Both also don't need as much flow as the CPU does. If you run them all in series, then your overall flowrate (and, consequently, the flowrate to your CPU block) will be lowered. You'd probably end up with higher CPU temps going that route. If you ran the GPU and NB in parallel after the CPU block, you'd end up with overall higher flowrates (and higher flowrates into the CPU block) because you wouldn't have increased restriction further down the line.

Would it work?

johan851 said:

That makes sense. What about this idea...if you're cooling your GPU, CPU, and NB, would it be a better idea to run the NB and GPU in parallel after the CPU? My reasoning is this...

The NB (and GPU too) are going to be more restrictive than the CPU waterblock. Both also don't need as much flow as the CPU does. If you run them all in series, then your overall flowrate (and, consequently, the flowrate to your CPU block) will be lowered. You'd probably end up with higher CPU temps going that route. If you ran the GPU and NB in parallel after the CPU block, you'd end up with overall higher flowrates (and higher flowrates into the CPU block) because you wouldn't have increased restriction further down the line.

Would it work?

Click to expand...

Thats exactly what I'm planning on doing.

it is very simple

If you use open, low restriction blocks, you have to use them in series, for they absolutely need to have high fluid-velocity to be able to perform well. (mainly as a result of there inferior internal designs).

If you have blocks with a relatively high resistance to flow, chances are that these blocks have internals a wee bit more advanced, turbulence inducing internal designs are a lot more resistant to flow, they have to be, else they won't work. With such blocks, series is the absolute wrong setup for optimal thermal performance. there you have to move to using them in parallel.
The best thing to do, is to use a combination of series and parallel configs.

for instance

the CPU block can be in it's own leg, and the GPU + NB blocks can get inline, forming the 2nd leg, of a 2-way split. this will insure that the CPU block always get superior flow-velocity.

Tis True that this could become a very complicated way of doing things, but that is unfortunatily one of those other things in life....no Pain == no Gain.

Using a WW with a Swiftech GPU and NB block in parallel, would put the majority of the water going through the GPU and NB. It seems to me that the number one thing you should be looking for is flow to your CPU block. With a WW, and Swifty blocks, you want them in series, but, with a Maze 4, a Z-chip, and some restrictive GPU block (For some reason you can never see the interior of the GPU blocks on the manufacturers site) then parallel would get you much more flow through the CPU block (personal experience)

E-Licious said:

WBs in series, rads in parallel, nuff said.

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Need to put rads in series too, if you're using heater-core style radiators (which most do).

Cathar said:

Need to put rads in series too, if you're using heater-core style radiators (which most do).

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Wouldnt it be better to run HCs in parallel because of greater deltaT