Huge Radiators: Roundup

[Martinm210]

I had some time to tinker around with the data again and tried my hand at a "watts dissipated" graph:



What has me worried about this is that it scatters my data points all over the place.

It would be nice to get more precision here. I think the graphs above show that longer load times wouldn't help me here. High-precision thermal probes of some type would be very nice, but they won't do much good if I can't hook them up to the PC to have them log their readings somehow. Any suggestions?
I was considering a Crystalfontz a while back, btw. The reason I didn't go for it is because while it has higher resolution than .5°, it's thermal probes have a precision of only .5°. So it was either the bigNG (very precise digital probes, but only .5° resolution) or the Fontz (high reolution, .5° precision probes). Seems to me that neither is better than the other...

@posts above: What the hell is wrong with M4 screws? How could threadless holes possibly be better than M4?

Very nice!

Here is the pdf of the Dallas sensors, at 20-40C, the absolute accuracy mean error is only -0.2C, but I believe they specify the absolute accuracy in terms of 3 standard deviations from 0-70C. The graph in the chart for the sensors notes that 3 standard deviations of error is worth about .25C, so two standard deviations (68%) would be around .17C which would capture 68% of readings. This seems about right from my experiments with multiple water sensors too...roughly .2C relative accuracy or better. That's pretty good for such a cheap instrument. Check out the tools the coolingmasters guys were using to get down to .01C, some of their temp monitors cost $5,000 just for the monitor This makes me very happy with my $50 Crystalfontz getting down to .2C...add multiple sensors and that gets even better..

http://datasheets.maxim-ic.com/en/ds/DS18B20.pdf

The real beauty of the CF is the ability to run 32 temp channels and 4 RPM channels at a time. You could easily make a testing rig with 4 air in per fan and several water sensors if you wanted to. The sensors do cost about $5 a pop though, so that can get expensive relatively quick. I'm only utilizing about 1/3rd of what it can do. I think when it comes to air...you can probably never have too many sensors, preferably they all need to be fixed in exactly the same location for each radiator too. I find that my air out readings don't seem very accurate and I think it's partially due to different fans, but also due to the manual placement of the sensors. I probably should have rigged up some sort of outlet shroud to keep the location consistent every time. Oh well, I'm not using those for any calcs, so I've given up on them for anything more than information.

Anyhow, I love the heat dissipated chart, very nice!

It's really interesting to see the push/pull charts in comparison too. The GTXs really like push/pull as you would expect for their high density