Originally Posted by stilllogicz @JackNaylorPE
What is the formula you use to calculate heat dissipation? I'd like to do some calculations of my own.
I just use Martin's test results..... I have tabulated them here ....
His tests are on the 360 and to get a 120, I simply divided by 3 ...... 240 times 2/3 ..... 480 by 4/3..... not going to be exact to the watt but easily within 1-2%. Several others have joined in working to expand upon the data..... and martin's input and encouragement has been helped keep the enthusiasm in the project going. Have about 40 peeps involved so far so if ya could provide any data you get would be most helpful.
The fan speed data was a simple interpolation initially but if ya on the detail pages, used martins actually recorded values to provide data for 50 rpm increments.
Originally Posted by Anarchy2703
Thermal coefficient of water is 0.00023129193. So I think you just take the surface area (or it might be volume) of your radiators and times it by that. For example: if you had a 420mm radiator (420*140*30) and a 280 (280*140*30) you could theoretically dissipate 680watts with a delta temp of 10 degrees c. But most systems produce over 680 watts at load, so to keep the thermal coefficient the same the delta T must rise. Hope that helps.
It's bit more complicated..... for one, that would indicate that a 45mm rad would give ya 50% more cooling than a 30 and it doesn't .... more like 2-5% depending on fan speed. It's also changes based upon fan speed .... let's say ya have 22C air coming in and a 32C water temp..... well as the air goes thru id it drops say 1C for every 4mm of depth in a 30mm rad.... by the end of the 30 mm, you'd be at 34.5C ..... at that point what is an extra 15mm of rad gonna do for ya with air at 34.5 and coolant at 32C, the rate of heat exchange is slowwww.
Originally Posted by stilllogicz
Monsta 360 = 442 Watts @ 2200 RPM
XT45 240 (in the front) = 248 Watts @ 2200 RPM
ST30 240 (in the side w/o HDD cage) = 187 Watts @ 2200 RPM in PUSH ONLY
Total = 877 Watts which puts me @ 63.5% heat dissipation.
This leaves me with more than enough cooling for both the GPU's and the rest of the system while keeping the component separate to maximize CPU overclockability.
Does everything add up?
1. 2350 is an extreme fan rpm ..... be aware that this will approach H100 sound levels .... IOW, vacuum cleaner levels
Corsair says 35 dBA ... so even giving them the benefit of the doubt .... that's 57 dBA and that Corsair number is in air not pushing air thru a rad.
2. 325 is not a big OC for the 290s..... the formula, if I remember correctly is stock power * (Voltage OC's / Voltage stock)^2 But again, you'll never see that outside stress testing and not all will hit 100% load so 325 is good.
3. Not sure that ya mean by the "rest of the system". I'm guessing that yoiu are using the top rad to cool the CPU which is prolly on the "overkill side". Ifrom what I have seen, very few are having their HW OCs limited by temperature, hence delidding is far less popular with HW as compared to IB. So while temps will likely be the limiting factor for those air cooling a HW CPU, for WC'ers, it seems to be voltage .... at my 4.6 OC, I'd be quite happy to try 4.7 or 4.8 as my OC temps at 4.6 are only 74C at 850 rpm.... but my voltage is at 1.48 now w/ the new BIOS (w/ avx instructions) and that makes me uncomfortable.
4. I'd throw a 420 in the top and with a more moderate 1800 rpm speed you;d get 423 watts outta that .... 60% of ya CPU load is 84 watts so that leaves and extra 339 for ya GPUs. At 1800 rpm, ya'd have 340 from the monsta, 207 and 161 from the others ... or 708 watts....with the spare 339 ya over 1000 watts .... so looking at 1400 ....
1380 + 135 CPU = 1515 x 60% = 909 watts
Monsta 360 = 270
XT45-240 = 165
ST30-240 = 133
Total = 904 watts
I think you will be a lot happier at 1400 rpm......as far as piping it I'd suggest:
GPU's 1 and 2 set up in parallel
GPU's 3 and 4 set up in parallel
Then have 1/2 and 3/4 in series, all fed by a 35x2....another alternate would be
Tack one of these onto the right side of the case with 4 or 8 x 180mm fans
http://www.frozencpu.com/products/19805/ex-rad-593/Watercool_MO-RA3_360_LT_9_x_120mm_4_x_180mm_Extreme_Radiator_-_Black_Powder_Coat_25000.html?tl=g30c95s667Edited by JackNaylorPE - 3/5/14 at 3:34pm