rad & TDP question/calculation

[jinsean]

I've been informed that radiator performance within the same line/family performs approximately linearly...

http://www.xtremesystems.org/forums/showthread.php?t=261055

So I decided to do a little estimating... please let me know if I'm on the right track.

I want to cool an Intel core i5 650 @ 110w (says extreme power supply calculator) & Radeon 6870 @ 151w (says the rumor mill). So rounding down, 260w of heat to dissipate in total.

The c/w rating of the XSPC RX 360 rad and the Swiftech MCR 360 are approximately .04 @ 600rpm (says skineelabs). So that means, the water delta above ambient will be .04 * 260 = 10.4.

So if I decided to purchase a single + dual rad (instead of a single triple rad) and have fans @ 600rpm, I'd still get close to 10.4 degrees above ambient for water temps.

So for my loop, a dual + single rad (swiftech MCR or xspc RX) @ 600rpm would be more than enough to cool the i5 650 & radeon 6870?

Thanks.

[Church]

Remember that when you overclock/overvolt it ramps up quickly power usage and heat dump aswell. Also different usage scenarios also impact heat dump (eg. basic desktop work / games / or folding, cpu & gpu stresstests). Check if that power supply calculator can take that into account aswell.

[antiacid]

I would think that it would be enough, for stock to mild overclocking on that i5. Then again, if you OC it, you'll be thermally limited at some point, no matter how many rads ;)

[jinsean]

Ok, thanks for the reassurance. When I first started WC'ing 3 years ago, I mainly went into it to attain a truly silent system. In hindsight, I went overboard on the rads (currently using 2 mcr-360s). I didn't understand how much heat I was trying to dissipate.

On the next system upgrade, I plan to go SFF if I can. So that's why I've been contemplating on a single + dual rad setup.

[relttem]

is that 110W+115W the total amount of heat given off or what is expected to be taken away by the water cooling system?

[skinnee]

actually neither... the power supply calculator is watts consumed by the system, not what is given off as heat or what is dumped into the cooling system.

But, close enough for estimation purposes.

[relttem]

I was just wondering..Skinnee..you still need a ticket?..let me know

[justin.kerr]

CES ticket? :p:

[skinnee]

I'm skipping CES and going to the AVN awards. :p:

[justin.kerr]

lucky you. lol Big Rock show for me. :rolleyes:

[Akula]

I might add like 20-30 watt to your initial 260 W to account for heat added by the pump and components that are air cooled inside the case.

[avddreamr]

Honestly, for that setup you should be able to get away with a dual 120mm rad.
The TDP on that cpu assumes the utilization of the onboard gpu right?

I would be surprised if you manage to create even 200watts of heat.

[jinsean]

@akula
I use a Dtek-DB1 so it probably has low to negligible heat dump into the loop. But thanks for pointing out the other hardware components.

@avddreamr
I meant to use the i5 750/760 lynnfield, but it still results in approx 100w. Thanks though.

[Vapor]

You'll be hard pressed to get 150W of heatdump into a WC loop from a Lynnfield w/o HT, fwiw.

The power supply calculator's base value of TDP is a huge overshoot and not all power consumed by the chip gets lost to primary cooling (via the chip and IHS and into the CPU block).