Originally Posted by owcraftsman
Maybe I said that wrong let me be less clear and more to the point lol
I have my doubts about any 45 mm rad being only 1 watt behind any 60 mm rad when you compare apples to apples that is to say 120 vs 120 140 vs 140 360 vs 360 or 420 vs 420. The physics make no sense.
First we need to recognize that we were not comparing apples to apples..... we were comparing a 45mm 420 (58,800 sq mm) with a 60mm 480 (57,600 sq mm) so the shorter depth rad has a slight surface area advantage..... it also has a smaller % of dead area behind the fan motor but that advantage is not accounted for.
And the thermodynamic .... we can talk about physics when fan turbulence comes up
..... the analysis is sound . And actually it does make sense when you take all factors into account and look at what is happening ..... You assumption would be valid is the air temperature was constant from top to bottom and the air flow was constant in both instances. WE don't have those two conditions and that's where the static model falls apart. We don't have a 'static" situation and and the fact that there is a temp gradient thru the rad must be recognized. If we can agree that the air coming out of a rad is hotter than the air going in, it is easy to see that the transfer of heat at the top is going to be greater than at the bottom....with ambient temps at ambient 24, here's a sample temperature gradient where the air is being heated as it goes thru the rad
So where will the greatest heat exchange take place ?....from the 35C water to the 24C air at the top or the 35C water to the 32C air at the bottom ? In addition, when ya have more depth, ya have more resistance and when ya have more resistance you have less air flow.....when ya have less air flow, ya have less heat exchange taking place.
I have a UT60 420 in the top had no problems installing, I have 10mm clearance to HS on mobo, 20mm to memory clearance no problems removing a fan for greater access to mobo screws, I placed the 420 as far forward as possible and it's not in the way of the 8pin eps at all and I'd venture to say the same is true with most mobo that don't have the EPS in the middle top of the board (poor choice by Asus), and I'll take UT60 420 over a XT45 420 any day of the week.
You should share your installation method as several peeps here had to disassemble half the case even to get even an XT45-420 in .... I stumbled upon a way to tilt and twist it in but my method wouldn't work on a 60mm. I don't have it as forward as possible as it woulda ruined the lineup of the rigid tubing and taken away my top drive bay. As it is now, I can still fit a Reeven Six Eyes in there. As for the EPS, we were talking specifically about the M6F which doesn't have it in the middle of the board. Jesse's build over at modzoo had it in the middle tho and he took out the UT60 because of cable concerns. If a UT60 is what ya want for aesthetics or other reasons, I have no issue with that..... but that won't change the thermodynamics, nor Martins / anyone else's test results
There may be little difference between a 480 and 420 according to the calculator you are using but the XT45-420 has approx 810,000 less sq mm of mass than a UT60-480
480*120*60=3456000 sq mm
420*140*45=2646000 sq mm
Mass would be cu.mm...... and extra mass is irrelevant when you no longer have an adequate temperature differential. The surface area argument is very valid but you have to account for the temperature gradient. Maybe it will be easier to understand this way.....
Stack two ST30's ..... with air being pulled in from the top of the case down thru the top rad, into the bot rad and out into the case .... Would you accept that the bottom rad's performance is hampered by the fact that its intake air is pre-heated by the top rad ..... same thing with thickness.
I know that's overly simplistic and actual surface area may vary a bit due to FPI etc but still hard to think it only a little bigger.
It's not hard to figure out if utilized properly (right fans) which one would perform better and me still thinks the difference is more than 1 watt.
The test are the tests .... they are not subject to interpretation, they are actual measured results.
This are the test results at 1000 rpm which is the typical range of flow in the Enthoo.....mine run about 44 in idle and 862 while gaming .... the results are so close, any variances are smaller than the margin or error :
ST30-360 = 150
XT45-360 = 149
UT60-360 = 151
Monsta-360 = 154
Now again, we are talking about low noise installations in the Enthoo using the Phanteks fans. If we were to refocus the discussion to higher density rads and higher speed fans, the discussion will change. The temperature gradient will shrink because the air is moving thru faster. At low speeds, the air has absorbed just about all it can by the time it reaches the other side of the rad .....the analogy "you already have ya 5 pounds of crap in the 5 pound bag" comes to mind ..... but push the air thru faster and your hypothesis comes into play..... now the extra depth will matter because by the time the air exits the tin rads under hi speed, the "bag" isn't already full.
At 1250 rpm, we start to see a spread tho 5 watts is not anything to get excited about
ST30-360 = 181
XT45-360 = 183
UT60-360 = 188
Monsta-360 = 197
At 1800 rpm now, we start to see what you are expecting start to happen.
ST30-360 = 242
XT45-360 = 257
UT60-360 = 269
Monsta-360 = 281
Now the UT60 will provide 4.5% more cooling with the same surface / fan area.
At 2200 rpm.....we jump to 6%
ST30-360 = 281
XT45-360 = 307
UT60-360 = 326
Monsta-360 = 365
What you are expecting was very much applicable in the days of 30fpi rads and hi speed fans where hi speed was needed to provide enuff SP to get the air thru. But at low speeds, extra thickness does not really help.... The WC industry has followed the auto industry in this respect .... I remember changing the rad in my 1965 Pontiac Tempest ....was about 24" square and had a thickness of 2.5" .... rehabbed my sons Xterra rad and changed the one in his jeep and they were very thin, wide and tall.
If ya want the absolute best temps, I'd lean towards high fpi, thick rads with 3,000 rpm fans. If noise is concern, then lower speed fans are required and with that, thinner rads will be much more efficient.