Water Cooling: Closed Loop Vs. Open Loop

[manofchalk]

180W...
You know that a standard Core i7 has a stock TDP of 88W, a moderate overclock like 4.5Ghz that barely requires a voltage increase is not going to add 100W to its power consumption.

Use this formula, it will roughly tell you what power consumption (and heat output) to expect from a particular overclock.
OC Wattage = TDP * ( OC MHz / Stock MHz) * ( OC Vcore / Stock Vcore )^2

 

[Karadjgne]

If I'm reading that formula correctly, and doing the math right, a jump on my 3570k from 3.4 stock to 4.5 OC puts my wattage at 154. Using the same numbers but with the 88w of an i7 puts it at 178. Not knowing the exact voltages of of someone's i7OC is say its gotta be pretty close either way. It's that, or my math is screwed lol.

 

[DHFF]

Yes runs at 80-90W stock but there are many chips that go way over that. An FX-8350 for example runs at 125W stock. Wouldn't take much overclocking to exceed 180W. An i7-3820 for Sandy Bridge runs at 130W. Again it wont take much to push these chips tot he point where they would need a very robust cooling system.

 

[Pcbuilder123]

Yep, lol. For a 6300 a tx3 isnt bad either, 125tdp great for a small cooler for relatively small oc's.

 

[Karadjgne]

I guess that's one thing I like about CLC's, they start at like a h-55 and work up to a h-110 in stages. With most common aircoolers you start with a tx3 then the EVO then nh-d14. And its 125w, 180w, 240w. And most of the other coolers just don't compare in performance.

 

[Pcbuilder123]

Larger variety price and performance along with different thog yo suit your needs. Low end clc's tend to be not as good as high end air coolers (same price though).

Have you seen this, somebody clc blew up because of the cold weather:https://www.google.com/url?sa=t&source=web&rct=j&ei=_IjMU4G5M8i9oQTcwYLABg&url=http://www.tomshardware.com/forum/281843-29-corsair-exploded&cd=1&ved=0CBwQFjAA&usg=AFQjCNF-tOuBzerL0UP1Ze1bbrHoKhXsJQ&sig2=Iv9wuJcJ4HTmL_XAgPepcg

 

[DHFF]

Thats is my recurring nightmare about liquid coolers. I am convinced that one day I would open my case and find my motherboard dripping in coolant.

 

[Pcbuilder123]

Thats is my recurring nightmare about liquid coolers. I am convinced that one day I would open my case and find my motherboard dripping in coolant.

Haha, aside from budget constraints, in my top 3 reasons to not buy liquid coolers

CLC
Top 3 cons
1.No point in my budget rig
2.Better air coolers for same price that are quieter
3.Risks of water cooling

Top 3 pros
1.Performs slightly better for serious overclocks (high end ones like a corsair 110
2.Look pretty cool
3.If you have a cool room and good fans it should be relatively quiet.

 

[DHFF]

Thats what I keep coming back too, Even with liquid cooling, it still comes back to the fans. So I budget in $100 for a Corsair H100i, but then I have to budget in another $50 for a pair of Noctuas. IF I take those same two Noctuas and put them in a push pull on my 212EVO, I should get similar performance and I would be spending about $65 less.

Now yes If you are seriously overclocking you can build a custom loop with large radiators ect. but then you are talking hundreds of dollars so for within the $100 range is seems smarter to go with an air cooler.

 

[Karadjgne]

Push/pull on a 212 does nothing but raise vrm temps and add more fan noise, jfyi, and when replacing the stock fan you need to be careful about cfm, if its too much greater than stock, you'll actually get worse performance as the heat from the fins does not have sufficient time to transfer tothe air passing over them.

 

[DHFF]

Adding more fan noise I can understand. but I am afraid I don't follow you on your last statement. A rapid flow of air will only increase heat transference. The testing team here at Toms demonstrated this in their CPU cooler reviews, the replaced the stock fan on each model with 2500RPM fans an in each case a lower temp was reported.

 

[Pcbuilder123]

Push pull only decreases temperatures by 2-3 degrees.

This is on an underclocked i5 3570k btw.

 

[tiny voices]

I would recommend NOT buying an fx9590. there is no reason to at all and DEFINITELY not worth the trouble.

 

[Pcbuilder123]

Yep, teksyndicate said there is no place in the market for it. AMD just wanted to impress people who don't know much about cpu architectures and for those who had compatible motherboards.

 

[Karadjgne]

Rapid flow of air does increase heat transference, upto a point, and once past that point it will slowly start a reversal. If the tower has a thinner width, what happens under very high cfm is the air blowsthrough so fast it picks up a lot less of the heat. Slightly slower air will absorb more heat before exiting the planes.

As far as the VRMs go, the air pushed into the tower has 'bleed' around the sides. It's this air that wafts over the VRMs and other components next to the CPU. Adding a pull fan, you draw that air through, so you don't get the bleed. It's one of the same situations that CLC's suffer from, since the CPU fan is located on the rad,

 

[DHFF]

I can see your point on the pull fan, that makes sense and I totally agree that liquid cooling loops subtract a portion of airflow over the RAM,chipset ect.. I know of a number of guys with loops that put intake fans on the bottom of the case or on the side panel for this reason.

As for the the heat sink fan blowing so fast that thermal transference breaks down, I dont think that is a realistic concern. Fans upwards of 3500RPM have been mounted on coolers with positive effects. Much faster then that most people do no use because noise becomes a factor. If you have research that shows just how fast the fan would need to move before the heat transfer breaks down, I would be very interested in reading it because now you have me curious

EDIT: I did some research on this . It is true that as the air moves faster it will be less efficient at absorbing the heat however the on the other hand as the air velocity increases, you are increasing the volume of air moving over the heat pipes so the overall amount of heat dissipated increases. So yes it becomes less efficient but you will never notice this efficiency loss because the increased volume will result in lower temps.

 

[Karadjgne]

That makes sense.

 

[Pcbuilder123]

+Karadjgne
As you are a power supply expert, what do you think of the xfx550 watt power supply? I am planning on buying that next month (as a 14 year old took me a while to save up), followed by a 1080p 24" asus ips monitor followed by an r9 280 or similarly performing nvida maxwell 8 series card. Is it powerful and good quality?

 

[DHFF]

I would go with something higher then 550 if you are throwing an R9 on. say something in the 750W-850 category. Check out this list for good power supplies and ones to avoid:
http://www.tomshardware.co.uk/answers/id-1804779/power-supply-unit-tier-list.html

 

[Karadjgne]

Here's the gimmick on psus. It's all about quality. The XFX psus are built in a Seasonic platform, andare in most opinions about as good as you can get. The XFX 550w has a very high 12v output, has excellent over-protections and imho is worth more than its price. It's one of a few 550w psus powerful and stable enough to power a 780ti with an OC pc.You really can't do better for the price, its an outstanding psu. If 550 makes you nervous still, the Antec 620m HCG, Seasonic m12II 620, or XFX650 are also excellent psus.