The impact of tubing sizes

[ranker]

Some questioned the correctness of old beliefs. Here's an analysis on an old-school system.

The system we're comparing is a DangerDen Maze 4, an Eheim 1048 or Eheim 1250, and a Thermochill HE120.2 with some decent fans on board. ~4 years ago, this was a high performance system in the USA.

Interactive flow-performance results, on an 80W mildly overclocked CPU of the same era may be found here.

The HE120.2 radiator performance curve can be found here. We'll be using the pink curve to represent the fans, which would be about the full-time tolerable noise limit for many individuals.

We'll be assuming a 120W CPU heat load though, which was more typical of the high-end overclockers of the day. Pump heat dump is ~10W for the 1250, and 5W for the 1048.

The flow rates between 3/8" and 1/2" are seen on this graph:



For the 1048:

3/8" => 4.8LPM
1/2" => 6.9LPM

For the 1250:

3/8" => 6.2LPM
1/2" => 9.6LPM

Looking to our Procooling graph, and multiplying the values by 1.5 (120/80), we get:

1048 1/2" to 3/8" delta => 1.4C
1250 1/2" to 3/8" delta => 1.8C

The estimated radiator water temperatures are:

For the E1048:
125W @ 4.8LPM => 5.4C
125W @ 6.9LPM => 5.2C
=> 0.2C delta

For the E1250:
130W @ 6.2LPM => 5.5C
130W @ 9.6LPM => 5.2C
=> 0.3C delta

With lower speed fans, the radiator performance deltas get slightly larger.

So the total delta for 3/8" tubing with barbs to 1/2" tubing with barbs is:

1048 => 1.9C
1250 => 2.1C

Those were the differences for just moving from 3/8" to 1/2", for the really heavy overclockers. Obviously that is what justified the move for many.

Like I've said for those who were wondering why things are different nowadays. Things have changed. Water-cooling has evolved.

I think most of us here at XS grasp the concept and understood how things have evolved and changed.

However, I feel sorry for the fight you're getting over on [H]. Seems like they're a little slow and trying to deliberately spin your results into championing how low-flow setups have been superior all along. (For those that are interested in seeing what happens when you anger the natives: http://www.hardforum.com/showthread....1200495&page=3)

I'm sure most people here at XS will appreciate this graph as it helps demonstrate your conclusions by allowing us to compare how it applied back then and how it applies to today's water cooling components.