GFX cooling: airflow or static pressure ?

[Gripen90]

I'm going for 3 reference cooled GTX 780's in my rig so I've sold my MSI GTX 780 Twinfrozr gaming card and am instead waiting for an EVGA GTX 780 SuperClocked with reference cooler to arrive.

In the mean time I want to upgrade the rest of my case fans and especially the ones I have attached to the optical/harddrive cages which cools the graphics cards from the rear.
However I'm usure whether is should use a normal high airflow CFM fan as a Corsair AF 120 High Performance 1600rpm fan or if I should use a high static pressure fan like the Corsair SP 120 High Performance 2350rpm fan for cooling the 3x GTX 780 from behind.

Since the cards are pretty close to the fan and the cards have "openings" revealing the aluminium fins in the rear, I'm thinking that the best choice of fan would be high static pressure SP 120 fans since it's essentially like a "close" radiator ?


Or am I completely wrong about this ?
BTW I'm putting the fans on a fancontroller to adjust to the best noise/performance ratio.

 

[jh30uk]

IMO a better case, one with modular HDD cages if that does not have them but looks tight as it is.

Many of todays cases are EATX/Ultra Tower and have a lot of room for SLI.

And just for you :

 

[almighty15]

Agreed...NZXT make some awesome cases as can be seen above

 

[Gripen90]

Thanks but that wasn't really the question. The pictures just show the same concept, but what I want to know is if a high cfm airflow fan or a high static pressure fan under these circumstances will provide the better cooling solution for the cards ??

I'm not changing case just for looks

 

[cwgk91]

Static pressure is for radiators, air flow is for case fans I believe

 

[jh30uk]

Thanks but that wasn't really the question. The pictures just show the same concept, but what I want to know is if a high cfm airflow fan or a high static pressure fan under these circumstances will provide the better cooling solution for the cards ??

I'm not changing case just for looks

I never said it was but IMO and I bet many here your case is a mess.

Its too small etc, look at that bottom photo for a prefect SLI set up, now you have 3 GPU's so swap that 120mm fan on bracket for a 140mm.

Do not throw any more money into that case for fans or other.

 

[Silent_Scone]

Three GK110s in SLi, all airflow options are the lesser of whichever evils.

Reference coolers are preferable with side intake and a fan as you'd demonstrated in your picture, however there will still be throttling present after long stints, or not even that long in fact.

Might not find this helpful, but honestly - just go water.

 

[jh30uk]

Would water even be practical in his case?

 

[shankly1985]

I like to use Static Pressure fans. They pin point the air much better I feel than air flow fans.

In no way am I 100% fact its just what works better for me.

 

[Silent_Scone]

Would water even be practical in his case?

Do you mean in his situation, or in his chassis? It's practical if you make it practical

 

[whyscotty]

IMO a better case, one with modular HDD cages if that does not have them but looks tight as it is.

Many of todays cases are EATX/Ultra Tower and have a lot of room for SLI.

Spoiler

And just for you :

^^^
This - If you're not going down the watercooling route



I tried to run TriSli on air for over 12 months - I was fighting a losing battle

If you really want to run 3 high end cards - Watercooling is your only long term solution IMO

 

[Gripen90]

I never said it was but IMO and I bet many here your case is a mess.

Its too small etc, look at that bottom photo for a prefect SLI set up, now you have 3 GPU's so swap that 120mm fan on bracket for a 140mm.

Do not throw any more money into that case for fans or other.

I know it's a mess. I've heard it for the last 6 years where ever I post pictures . I've run 3-way SLi as a permanent solution in this case, since 2009 but I never have had heat issues with 3x GTX280/470/580/670 - and I still don't but I wouldn't mind it being cooler still.

The max case height of any case that will fit to my current living situation is 54,6cm in height. That's doesn't make full tower cases an option.
Also there are no real cases out there that I like the looks of. I have a Corsair 540 collecting dust because I don't really like it, and it doesn't fit the spot. I have another PC with a Aerocool XPredator X3 case which has great cable management but worse airflow modding options than the old CM690.
I may swap case if a CM690 III nVidia Edtion gets released.

Three GK110s in SLi, all airflow options are the lesser of whichever evils.

Reference coolers are preferable with side intake and a fan as you'd demonstrated in your picture, however there will still be throttling present after long stints, or not even that long in fact.


Might not find this helpful, but honestly - just go water.

After 2hrs of COD Black Ops II my cards still run at their max boost clock 90% of the time (vaires a bit when some scenes don't take much GPU usage) - I haven't OC'ed them because then I know they'll get hotter and perhaps not boost as high as they could. (I set power target to 103% and target temp limit to 80°c in MSI AFB)

Would water even be practical in his case?

Nope - also I change graphics card about once a year so H2O isn't that viable solution for me.
I'm still impressed with what you can achieve with air if you know how to place it and if you don't mind a bit noise when it's needed.

I like to use Static Pressure fans. They pin point the air much better I feel than air flow fans.

In no way am I 100% fact its just what works better for me.

Thanks - It was also what I was thinking since there would be some obstruction right behind the fan, so some better static pressure to force the air into the cards heatsinks would be the way to go...(I think). I've prepared a set of SP 120 now and am just painting the rings green. I have a SP120 2350rpm attached to the sidepanel and it helps a bit too overall.

 

[Silent_Scone]

Meh, it's all subjective to the extreme. I change GPUs like hot dinners but water just makes so, so much more sense with multi GPU setups. It's one of the reasons I used quick disconnects so that I could easily remove the cards without having to drain.

Horses for courses I suppose.

 

[jh30uk]

Do you mean in his situation, or in his chassis? It's practical if you make it practical

chassis

 

[Gripen90]

Meh, it's all subjective to the extreme. I change GPUs like hot dinners but water just makes so, so much more sense with multi GPU setups. It's one of the reasons I used quick disconnects so that I could easily remove the cards without having to drain.

Horses for courses I suppose.

Yea I know - quick connects does make it a whole lot easier.
It's just that getting all the stuff an new GPU cooling blocks each time for a new GPU (times three) also costs a bit too
When I buy new cards I always go with the cheapest reference cards I can find at the time - it usually make the difference if there enough cash for 2 or 3 cards.

 

[Silent_Scone]

Yeah I feel your pain, I just wince and get it over with lol

And agree with three card setups, there isn't much point going for 3rd party designs for overclocking etc as you're still CPU bound. Makes much more sense to stick to reference

 

[Gripen90]

Yeah I feel your pain, I just wince and get it over with lol

And agree with three card setups, there isn't much point going for 3rd party designs for overclocking etc as you're still CPU bound. Makes much more sense to stick to reference

Indeed it does :

Just getting the final layers of green paint on the corsair fan rings... I hope they will get dry before thursday - not easy in this cold weather. I've taken them inside and put them in the attic because it stinks !

 

[Avenged7Fold]

Static pressure fans focus air in front of them to allow for enough force to go through radiators, grills etc. In a case like this, they can be useful to point air towards graphics cards, HOWEVER static pressure fans only show SP measured directly in front of the fan, this spec is effectively no good to you, as the cooling is needed further away and for all you know, the air flow at that distant could be worse as a result of focusing the air closer to the fan specifically for use with heatsinks or radiators. The static pressure figure given irrelevant for this use, so people saying SP fans are not good as case fans are not necessarily correct, as SP at a distance from the fan would be dependent specifically on the fans design (which vary even between just SP fans, normally not an issue because they are mounted to whatever you are cooling, not a distance away from it).

SilverStone has made some large SP fan designs which focus on keeping air concentrated in a column, not just in front of it. If you can find a way to mount one for this, it seems ideal for the situation. They had several videos on their site showing the effect of their fan designs over others, using smoke to show where the air is concentrated and how the concentrated column of air lasts till it dissipates.

Painted my SP rings the other day florescent orange. Did around 3 or 4 layers in a few hours with acrylic modeling paint i bought from a model shop down the road. Stuff dries in 15-20 mins, is acrylic safe and does not really smell! In fact, it was raining outside, so i moved the drying rings to the tiny downstairs bathroom and the smell was barely noticeable. Bad idea though, as i got lazy and decided to do my final coat of paint in the bathroom... now my was pristine white bathroom has specs of florescent orange on the wall/floor.

 

[Gripen90]

Static pressure fans focus air in front of them to allow for enough force to go through radiators, grills etc. In a case like this, they can be useful to point air towards graphics cards, HOWEVER static pressure fans only show SP measured directly in front of the fan, this spec is effectively no good to you, as the cooling is needed further away and for all you know, the air flow at that distant could be worse as a result of focusing the air closer to the fan specifically for use with heatsinks or radiators. The static pressure figure given irrelevant for this use, so people saying SP fans are not good as case fans are not necessarily correct, as SP at a distance from the fan would be dependent specifically on the fans design (which vary even between just SP fans, normally not an issue because they are mounted to whatever you are cooling, not a distance away from it).

SilverStone has made some large SP fan designs which focus on keeping air concentrated in a column, not just in front of it. If you can find a way to mount one for this, it seems ideal for the situation. They had several videos on their site showing the effect of their fan designs over others, using smoke to show where the air is concentrated and how the concentrated column of air lasts till it dissipates.

Painted my SP rings the other day florescent orange. Did around 3 or 4 layers in a few hours with acrylic modeling paint i bought from a model shop down the road. Stuff dries in 15-20 mins, is acrylic safe and does not really smell! In fact, it was raining outside, so i moved the drying rings to the tiny downstairs bathroom and the smell was barely noticeable. Bad idea though, as i got lazy and decided to do my final coat of paint in the bathroom... now my was pristine white bathroom has specs of florescent orange on the wall/floor.

Thanks for feedback
Well there's nothing elso to do than try with the SP120 fans and see if they'll be more effective than the existing Cooler Master A12025-12CB-3BN-F1 fans.

The paint should be ready for tomorrow mounting of the fans it's almost 100% dry now after 3-4 layers.

 

[Gripen90]

Is all done now.