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View Full Version : Anyone explain this graph

jackal2513
05-08-03, 08:06 AM
can ayone explain this to me, i understand that the x axis represents flow but not too sure what the y axis means .... cheers:

http://thermal-management-testing.com/wbCWcomp.gif

WejRepus
05-08-03, 08:10 AM
i believe that is the change in degrees celieus for every watt...
basically, for every watt the temp will rise by the value in the y axis

Cathar
05-08-03, 08:30 AM
Yes, the Y axis represents how hot the heat source (CPU) will get above the coolant (water) per watt of energy.

If a CPU is emitting 70W, and the C/W is 0.25, then the CPU will climb to 70 x 0.25 = 17.5C above the water temperature.

Mind you, the graphs specifically refer to a 10x10mm heat die and not a CPU specifically, but the correlations are close enough to give you an informed idea of which waterblock will perform better than another.

jackal2513
05-08-03, 08:35 AM
hmm.. and teh graph for teh whitewater is like miles lower than any of them !

It looks as if even though my innovatek Rev3 is pretty darn good at low flow rates, it woudl still be better at high flow rates.

Anyone know what sort of flowrate you actually get in a system.. for example 1.5 metres of 3/8th tubing and 3 rads and a 1048 ? Someone once said that you only get aroudn 60 lph with 3/8 tubing ???

cheers

Rich

Cathar
05-08-03, 09:02 AM
Originally posted by jackal2513
hmm.. and teh graph for teh whitewater is like miles lower than any of them !

;)

Originally posted by jackal2513

It looks as if even though my innovatek Rev3 is pretty darn good at low flow rates, it woudl still be better at high flow rates.

Anyone know what sort of flowrate you actually get in a system.. for example 1.5 metres of 3/8th tubing and 3 rads and a 1048 ? Someone once said that you only get aroudn 60 lph with 3/8 tubing ???

cheers

Rich

You're probably around the 180lph mark with that setup (3lpm) as a rough guess.

jackal2513
05-08-03, 09:17 AM
thanks cathar ..... nice to have a roiugh idea what it might be

would the same system but 1/2 inch tubing have like double the flowrate ~ 6lpm ?

I am thinking about converting the pump to block and block to Y splitter (before parallel rads) to 1/2 inch.. so approximately just under half the system would be 1/2 in.... not sure if it will make any difference though ?

Cathar
05-08-03, 05:15 PM
Originally posted by jackal2513
thanks cathar ..... nice to have a roiugh idea what it might be

would the same system but 1/2 inch tubing have like double the flowrate ~ 6lpm ?

Not at all. You might gain 10-20% higher flow rates at best.

jackal2513
05-09-03, 03:55 AM
okay thanks

definitely not worth it then, 3lpm to 3.3 lpm will only amount to at best, around a 0.3 degree C temperature drop at 70 watts ...