More Radiator-Sandwich testing

[Martinm210]

Martin, thanks for your input. I appreciate that very much!

I've also noticed, that Radiator, room and fans need to be warmed up first, to be able to get repeatable results. The fans seem to warm up very quickly but it takes a while for the whole loop to warm up.
With radiator testing, there are still some things I don't have enough control over. For one thing, I can't log fan speeds and neither can I log the Wattage of the heaters. Although the latter seem to be very constant. But as one can see from taking a close look at my data and as some have pointed out, there are still minor inconsitencies to be found. I certainly can't (and don't mean to) claim that my results are spot on, down to the decimals. But I think my testing is good enough to provide a rough overview. I can say what's clearly better and what's clearly worse, but maybe not what's marginally better or worse.

For testing CPU-blocks, I'm much happier with my results (some wil be up in a few weeks). I've managed to tune my methods to a point where it's not rare to see a total deviation of less than .2K accross three mounts so I'm very happy with that.
Which reminds me: I tested a few different CPU loading programs (Prime95, IntelBurn, CoreDamage, MaxPerf) to see which is most constant in temperatures and which produces the most heat. I could post some data on that here too, if anyone cares to see it.

Anyway, back to Martin's post.
I grabbed a random three hours out of the logs of my radiator tests:



Lowest temperature during this time was 20.8°, highest temperature was 21.7°. It looks like there might be a slight upwards trend here. Would you say that this is a tolerable kind of fluctuation for valid testing?

As for the monetary reward for testing: I couldn't agree more with you, Martin. It's not worth it in any way. It's only curiosity that gets me testing these things. If I just wanted a bunch of rads or waterblocks for myself, I go the cheap route and buy 'em. ^^

Cheers,
Shane

That's great!

I think I was generally pretty happy when my ambients and everything was holding withing about .5C over a 30minute period.

I couldn't log wattage either automatically, so I just manually recorded the watts used on about 15minute intervals and averaged them. You're household power must be better than mine. I could see pretty big fluctuations in voltage and I think that was part of my fan RPM variation as well. Trying to pin down say a 300 watt heat load would usually mean a fluctuation from 290-305 watts or so, so my power grid is a bit more up and down. My fan RPM would also generally go up or down +- 25-40RPM or so, but the crystalfontz logged it all, so I just averaged the recordings.

In the end, I think the hardest part for me when radiator testing was the testing of low speed fans, they were much more difficult to get good repeatability for me than the medium/high speed fans. CPU thermal testing is even worse for me.

The rad testing is very interesting. I appreciate you doing this sandwich work, that had to take you a huge amount of time. I wish I still had the passion for it, but even after 4 months of vacation I still don't even want to look at the testing equipment especially in regards to thermal testing. The hydraulics side of things is more interesting to me for some reason, too bad flow rate impacts are so insignificant....oh well.

Hopefully Swiftech will provide some additional testing specific to the MCR series. Even if it's only a 10% gain, that would still provide about the same gain a double thickness type rad would. It's not going to be huge by any means, but at least it's an option if you only have the space for one or two stacked. I think the results here are spot on, stacking rads just isn't going to do much of anything for really low speed fan use. Gains will only be measurable with medium to high speed fans.

Carry on with the great science and work for the good of the whole