Okay - in summary without getting into detailed explanations which have been explored in great depth at other forums.
Pumps
Note that I'll only talk about quality pumps. In my mind using budget pumps which may break down early, or are prone to leakage, is just false economy. You'll either need to replace the pump soon, or it will fail potentially causing damage to equipment.
Best performance pump period - Iwaki RD-30 (note - NOT the MD-30)
This is based upon careful assessment of the pump's heat dump into the cooling loop, its efficiency at converting electrical input power into pumping power, and the flow rate range and pressure supplied. Even though it is a 24v pump, running it at 17-18v yields the desired characteristics that makes it the "ultimate" pump.
Best low noise pump and compact pump - Laing DDC (MCP-350, DD-DDC)
Best low noise pump with broad flow rate charactersics - Swiftech MCP-655 (which is a very recently revised near-silent version of the old and noisy Laing D4).
Most efficient moderate pumpwith moderate noise - MCP600/AquaExtreme DC12-50Z
For lower flow systems where the expected flow rate is 5LPM or less, coupled with smaller tubing sizes, the DDC is hard to best. For moderate-high flow rate systems it's a close tie between the MCP600 and the MCP655. The 600 is more efficient and dumps less heat, but the 655 is more powerful and quieter. Hard to separate the two, and really depends on per-user criteria.
Tubing
My philosphy with tubing is that it's just there to carry the water to/from components. The thinner the tubing is, the more restriction it adds for no benefit. If one is concerned about performance then why add unneeded restriction which reduces flow rates and reduces performance? For aesthetic reasons people may want to use thinner tubing, and in fact thinner tubing may very well be suitable for certain setups where the flow rates are low enough that the tubing doesn't offer excessive restriction.
1/2" ID tubing with 3/4" OD is out. Dead. Don't use it. It is silly, oversized, heavy, expensive, and just downright not required unless you have a very specific need to chase flow rates much greater than 10LPM.
Best performance tubing (up to 10LPM flow rates): 7/16" ID tubing with 3/32" wall thickness (5/8" OD) slipped over 1/2" barb fittings. This provides the same flow rates as 1/2" ID tubing, will bend corners just as well as 1/2" ID tubing, but will do so with less effort. It weighs half as much, costs much less, is thinner and easier to route then 1/2".
Best compromise tubing (up to 6LPM flow rates): 3/8" ID tubing
If, through a combination of the pump being used and the waterblock components being used that the flow rates of the system will never be that high, then it is okay to use thinner tubing as per the user's aesthetic wishes. However, the following flow rates should be kept in mind when deciding whether a certain tubing size is suitable, or if a larger tubing size probably should be chosen:
8mm ID tubing => Up to 4LPM flow rates
7mm ID tubing => Up to 3LPM flow rates
1/4" ID tubing => Up to 2LPM flow rates
If the system is never going to get above those flow rates regardless of what tubing size is being used, then by all means feel free to choose and use a smaller tubing size. For tubing sizes under 3/8" though - it is preferable that compression, rather than barb, style fittings are used.
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Hmmm - that'll do for starters. This is turning out to be longer than I thought. I'll make an additional post later covering: radiators and radiator fans, and reservoirs.
For CPU and GPU blocks, if you're after ultimate performance just look at the various reviews scattered about the place, but pick reviewers who know what they're doing and use good testing procedures and explicitly mention and make an effort to control all the variables involved. I do not believe that hard-drive and northbridge blocks are necessary at all. I do believe that mosfet blocks would be nice to have, but no-one makes them, nor do many motherboards support their installation.
For my main personal setup I use an Iwaki RD-30 pump, 7/16" ID tubing, an actual car radiator with 3 low-noise fans drawing air through it set up in a radiator box, a Storm/G5 CPU waterblock, and a custom-made GPU waterblock
Pumps
Note that I'll only talk about quality pumps. In my mind using budget pumps which may break down early, or are prone to leakage, is just false economy. You'll either need to replace the pump soon, or it will fail potentially causing damage to equipment.
Best performance pump period - Iwaki RD-30 (note - NOT the MD-30)
This is based upon careful assessment of the pump's heat dump into the cooling loop, its efficiency at converting electrical input power into pumping power, and the flow rate range and pressure supplied. Even though it is a 24v pump, running it at 17-18v yields the desired characteristics that makes it the "ultimate" pump.
Best low noise pump and compact pump - Laing DDC (MCP-350, DD-DDC)
Best low noise pump with broad flow rate charactersics - Swiftech MCP-655 (which is a very recently revised near-silent version of the old and noisy Laing D4).
Most efficient moderate pumpwith moderate noise - MCP600/AquaExtreme DC12-50Z
For lower flow systems where the expected flow rate is 5LPM or less, coupled with smaller tubing sizes, the DDC is hard to best. For moderate-high flow rate systems it's a close tie between the MCP600 and the MCP655. The 600 is more efficient and dumps less heat, but the 655 is more powerful and quieter. Hard to separate the two, and really depends on per-user criteria.
Tubing
My philosphy with tubing is that it's just there to carry the water to/from components. The thinner the tubing is, the more restriction it adds for no benefit. If one is concerned about performance then why add unneeded restriction which reduces flow rates and reduces performance? For aesthetic reasons people may want to use thinner tubing, and in fact thinner tubing may very well be suitable for certain setups where the flow rates are low enough that the tubing doesn't offer excessive restriction.
1/2" ID tubing with 3/4" OD is out. Dead. Don't use it. It is silly, oversized, heavy, expensive, and just downright not required unless you have a very specific need to chase flow rates much greater than 10LPM.
Best performance tubing (up to 10LPM flow rates): 7/16" ID tubing with 3/32" wall thickness (5/8" OD) slipped over 1/2" barb fittings. This provides the same flow rates as 1/2" ID tubing, will bend corners just as well as 1/2" ID tubing, but will do so with less effort. It weighs half as much, costs much less, is thinner and easier to route then 1/2".
Best compromise tubing (up to 6LPM flow rates): 3/8" ID tubing
If, through a combination of the pump being used and the waterblock components being used that the flow rates of the system will never be that high, then it is okay to use thinner tubing as per the user's aesthetic wishes. However, the following flow rates should be kept in mind when deciding whether a certain tubing size is suitable, or if a larger tubing size probably should be chosen:
8mm ID tubing => Up to 4LPM flow rates
7mm ID tubing => Up to 3LPM flow rates
1/4" ID tubing => Up to 2LPM flow rates
If the system is never going to get above those flow rates regardless of what tubing size is being used, then by all means feel free to choose and use a smaller tubing size. For tubing sizes under 3/8" though - it is preferable that compression, rather than barb, style fittings are used.
__________________________________________
Hmmm - that'll do for starters. This is turning out to be longer than I thought. I'll make an additional post later covering: radiators and radiator fans, and reservoirs.
For CPU and GPU blocks, if you're after ultimate performance just look at the various reviews scattered about the place, but pick reviewers who know what they're doing and use good testing procedures and explicitly mention and make an effort to control all the variables involved. I do not believe that hard-drive and northbridge blocks are necessary at all. I do believe that mosfet blocks would be nice to have, but no-one makes them, nor do many motherboards support their installation.
For my main personal setup I use an Iwaki RD-30 pump, 7/16" ID tubing, an actual car radiator with 3 low-noise fans drawing air through it set up in a radiator box, a Storm/G5 CPU waterblock, and a custom-made GPU waterblock