Thinking of upgrading my CPU cooler...

[JrClocker]

I just use Prime95 (ver 28.5 or higher) for stability testing. I have had all other tools say things are stable, but fail with Prime95 (ver 28.5 or higher).

I only run this for about 10 minutes as the first test, as this version draws about 200 W of power into the CPU.

Every other stress utility that I have run (Intel, AIDA64, Prime95 (older than ver 28.5), SETI@home, my own FEA programs, etc.) keep the CPU at 72 C with less than 120 W of power draw into the CPU.

For a given cooler setup, CPU Power Draw determines CPU Temperature over ambient.

CPU Power draw goes up as frequency squared for a given voltage (i.e. a 10% increase in frequency will increase the power draw by 21% for a given voltage).

CPU Power draw goes up as voltage squared for a given frequency (i.e. a 10% increase in voltage will increase the power draw by 21% for a given frequency).

The current overclock is at 4.2 GHz (900 MHz over stock), and the core voltage is 1.15 (I think...I'm at work) with everything else on auto.

My current gaming session is as follows:
- Run SETI@Home on 50% of my processor and both my 970 graphics cards...uses ~55% of processor and ~55% of each GPU
- Play Elite Dangerous...processor load increases to 65% to 67%, each GPU increases to 85% to 90% load
--- Processor power about 110 W, each 970 running at about 110 W each.
- Temps on processor stay below 70 C on highest core, fans on cooler running at about 67% (I can barely hear it)
- Temps on each GPU stay under 80 C with 100 MHz overclock on each GPU, fans hit about 45% to 50% (I can barely hear it)

The power draw from my rig during this session is usually around 500 W from my UPS.

After 8 to 10 hours of gaming, the temps are still the same...the fans increase but a bit, but not much...and the ambient in my home office increases about 4 C (78 F to about 85F).

When I bought the PC, I didn't spec a higher end cooler as I wasn't expecting to overclock...then I found this site!

 

[JrClocker]

I'm happy with 4.2 GHz, but this overclocking is fun!

Assuming I want to hit 4.5 GHz, it looks like I will need at least 1.35 V on the core. So, I will need to increase my cooling efficiency by:

Processor Increase: (4.5/4.2)^2 = 1.148 (14.8%)
Voltage Increase: (1.35/1.15)^2 = 1.378 (37.8%)
Cooling Efficiency Increase: 1.582 (58.2%)...let's say 65% to be safe.

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Using the Prime95 (ver 28.5 and higher) power and temperature numbers:

According to the the Intel datasheet (http://www.intel.com/content/dam/www/public/us/en/documents/guides/core-i7-lga2011-3-tmsdg.pdf), I figure my current total thermal resistance is about (93 - 43.2)/195 = 0.256 C/W.

According to Asetec, the 550 LC hits about 0.1 C/W at 70 CFM of airflow. (I have the Jetflo 120 fans in push/pull on the radiator, so I am getting at least 70 CFM at max speed...factoring in the thermal paste, the 0.1 C/W is a good estimate).

That leaves the processor at 0.156 C/W (better than the 0.17 C/W max spec...yay!).

--------------------
Continuing with the Prime95 (ver 28.5 or higher) values, for the proposed overclock, the cooling load will increase to: 200 * 1.65 = 330 W.

This means that my total thermal resistance will need to be: (93 - 43.2)/330 = 0.151 C/W. This is impossible to hit for the 330W load (estimated Prime95 ver 28.5) as that is lower than the calculated thermal resistance of the processor.

If I target 300W instead, my total thermal resistance will need to be: (93 - 43.2)/300 = 0.166 C/W.

Assuming the processor thermal resistance stays at 0.156 C/W, the cooler + thermal paste would have to have a thermal resistance of 0.01 C/W.

--------------------
This article (http://www.anandtech.com/show/7738/closed-loop-aio-liquid-coolers/9) shows that the H100i thermal resistance (with paste) to be 0.0772 C/W...which will only get me to 213 W...not anywhere close to what I would like.

So...I agree that the H100i is "junk" in the context that it is only about 13% better than what I have now...for double the size radiator. I could probably setup push/pull and gain another 5% or so.

I cannot find any spec on the Swiftech unit for thermal resistance...does anybody know where I can get this?

 

[ATMINSIDE]

Take a look at the temps here:
https://www.techpowerup.com/reviews/Swiftech/H240-X/6.html

Even if you can't quite get 4.5GHz with it (which is largely dependent upon the CPU anyway), the H240-x is the top of the pack in both temperature and noise of any AIO on the market.
You want better? Go custom.

 

[JrClocker]

Interesting article...looked up the datasheet on the 4770K (http://www.intel.com/content/dam/ww...h-gen-core-family-desktop-vol-1-datasheet.pdf), thermal spec is PCG 2013D...TPD is 84 W versus the 5820K 140 W....(wow)

An interesting note, is that the thermal resistance of the 4770K package is 0.33 C/W. The 5820K package is 0.170 C/W...lower is better! (with mine calculated to be 0.156 C/W)

Using the H100i 0.0772 thermal resistance number above, at the 84 C max temp, it looks the processor power in the article was at about: (84-45)/(0.0772 + 0.33) = 95.8 W.

Using this 95.8W number, the H-240x thermal resistance (with paste) works out to be: (79-45)/95.8 - 0.33 = 0.025 C/W. That is a crap-ton better than the H100i!

+1 that the H100i sucks compared to the Swiftech!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


The Corsair H100i would allow me to cool a max power load (to 93C) of: (93-43.2)/(0.156+0.072) = 218 W.

The Swiftech H-240x would allow me to cool a max power load (to 93C) of: (93-43.2)/(0.156+0.025) = 275W.

WOW!

+100 that the H100i sucks compared to the Swiftech!!!!

If I did "good" in the silicon lottery, that equates to a 4.5 GHz overclock at 1.275 V vs 1.35 V.

With my current processor overclock @ 195W (Prime95 ver 28.5):

H100i max core temp: (0.156 + 0.0772)*195 + 43.2 = 88.7 C
H-240x max core temp: (0.156 + 0.025)*195 + 43.2 = 78.5 C

WOW WOW WOW!


For Reference:
- Prime95 power draw at my current overclock = 195 W
- All other tools (Intel, AIDA64, etc) at my current overclock = 125 W


Thanks guys - appreciate your help...and you might have talked me into something!

 

[ATMINSIDE]

The difference on the CPU is because the 1150 chips have TIM between the die and IHS while the 2011 chips have solder.

That power usage sounds about right, and that's definitely a great jump for the resistance on the H240-x.
I come from a BSME and work as an application engineer, so seeing someone else crunching numbers like this is nice. Kudos there
Don't forget though, this coefficient will change as temps change, and also that you'll hit a thermal limit of the radiator at some point.

Part of the reason for this difference is, the block on the H240-x is actually one that's sold for custom water cooling.
It's also just better components in general.

Like I say, you can always go custom, but I don't know of a better option for a "ready to go" setup.

 

[JrClocker]

Hey ATMINSIDE...the article you referenced and the one I referenced show different results (and the one I referenced doesn't have Swiftech as a reference). The one I referenced said the H105 is worse than the 110, and your reference says the H105 is better...sigh...if it's on the internet, it must be true...right?

I am a bit leery about having to change/flush the coolant...I think you have to do this with the Swiftech...correct?

If this is true...the H105 appeared to be pretty close to the Swiftech...any thoughts on the H105? (It has a thicker radiator than the 110...so it can support a higher heat load)

 

[ATMINSIDE]

Incorrect, you don't have to change/flush the coolant on any AIO, the Swiftech included.

H105 is still MUCH louder than the Swiftech.

 

[caddi daddi]

and the corsair fans and pumps fail more often on me than many others.

 

[Tech Tweaker]

Not entirely comparing apples to apples, as the H100i GTX is a 240mm AIO LCLC and the H240X is a 280mm AIO.

So, the H240X should do better just by nature of the fact that it has more mass to its radiator.

 

[JrClocker]

OK - this whole discussion may be null and void...as I don't think I can fit a 240 mm radiator into my case...it's a CyberPowerPC X-Saber (can't find any specs on it). See the picture below:



On the left side you see the front fan for my current 120mm Asetec 550LC.

On the top side, you see 2 120mm fans mounted. The left fan come pretty close to the motherboard connector (I have the wires tucked under the fan).

If I put a 240 mm radiator here (there are mounting holes for it), the fans would move "down", and hit the heat sink on the motherboard and the motherboard connector.

How would I get a radiator into this position? The only thing I can think of is to put the radiator where the fans are, and mount the fans external (there is a grommet in the upper left corner I could run wires through.) I am leery of putting the fans external for safety (both me being dumb, and my cat who hangs out with me).

When I bought the PC I chose this case so that it would fit under my desk..I wasn't planning on overclocking...then I found you guys!

 

[ATMINSIDE]

Fan guards!

That said, does the CPU power connector extend out to where the fans are?
If not, it's very possible it'll work fine.

Note, the H220-x is 240mm and the H240-x is 280mm.

 

[JrClocker]

I don't understand the question.

If the fans move "down" by the thickness of a radiator, the right one would hit the right side of the black/red heat sink on the motherboard. The left fan wouldn't even make it that far as it would hit the motherboard connector.

Does that make sense?

 

[ATMINSIDE]

Okay, that makes sense.

In some cases, if you move the fans downward like that, they won't actually hit the connector.

 

[JrClocker]

It's not worth it to mod the case for this...

But, I can get a new one! What do you think of this:

https://www.nzxt.com/product/detail/154-n450-noctis-gaming-mid-tower.html

(Sorry on my cell phone)

 

[ATMINSIDE]

The Noctis 450 is very nice and would fit a 280mm radiator up top

 

[JrClocker]

Newegg has it for $139!

Amazon for it for $153...

Now a talk me out of it before I drop $140 on the case, $150 on the cooler, and heck another $150 on the power supply (as I'm in there!)

 

[ATMINSIDE]

What PSU?

 

[JrClocker]

I've had my eye on an EVGA and Corsair 1050 W 80 plus gold models (modular of course)...don't remember model nimbers

 

[ATMINSIDE]

I've had my eye on an EVGA and Corsair 1050 W 80 plus gold models (modular of course)...don't remember model nimbers

WAY more than you need...
An EVGA SuperNova G2 750W is plenty for you.

 

[JrClocker]

Yeah - I know that...right now I draw about 550 watts with my sli setup when I am hard gaming.

My future will be a higher end graphics setup when I can't game at ultra at 5760x1080.

Just planning ahead!

My current PSU is not a name brand...and other folks on this forum have made me paranoid (even though there is nothing wrong with my PSU)!

I do like the modular concept...clean build.

I have a BSEE and an MBA (with 18 patents - hehe). My motto has always been "It has to work great and look awesome!"