[SOLVED] Can my cooling be more efficient? (Planning to overclock.)

[danytancou]

Hi all,

For five years now, I've been running an i7-4770K on a Gryphon Z87 m0b0 (no Assistant fan) with 16GB RAM and an ASUS GTX 770, all at stock speed. The GPU is stock-cooled, the CPU by an H80i cooler mounted at the bottom of the case, and everything is housed inside a Fractal Designs Define Mini case; the H80i is mounted at the bottom (it was most logical place I figured for it when I built the system). All fans except one are Noctua, spread around as follows:

- 1 x NF-P12 at the Front (Lower), for Intake (partially blocked by an HDD)
- 1 x NF-P12 at the Front (Upper), for Intake (partially blocked by two HDDs)
- 1 x NF-A14 at the Top, for Exhaust
- 1 x Corsair 120mm the Back, for Exhaust (the Noctua NF-S12A I had there broke, and I haven't had time to replace it with the same yet)
- 1 x NF-A14 at the Side, for Intake
- 2 x NF-F12 on the H80i's Radiator, set up for Exhaust

The system (picture here) has been running great for five years; I never had any need to overclock it, but now I do. I take it apart and clean it once a year (there's never much dust buildup), including re-applying thermal paste to the CPU & GPU.

As I was doing this very thing last night, I started thinking about how efficient my cooling actually is, and with the proposed overclock in mind, what if I were to turn the Radiator fans around, so they're Intake instead of Exhaust... This would create more positive pressure inside the case but that's not a bad thing. (As far as I can tell, it's currently pretty balanced, but leaning a bit towards positive.) To counteract that, AND to ensure that my video card isn't affected by the hot air blowing onto it from the "inside" Radiator fan, I figure I could turn the Side fan around and make it Exhaust rather than Intake.

(Making the Back fan Intake wouldn't do much good unless I do the same with the Top (else air coming in from the back will just be sucked out through the top), but this would make for pretty high positive pressure and it seems weird to me--maybe it's not though?)

What do you guys think? I'm not planning to do any kind of crazy overclocking, but hoping to get to at least 4, maybe 4.1GHz. Do I even need to worry about making any changes to the airflow?


Thanks so much!

Dany

 

[luckymatt42]

There's so many variables that the only way to know for sure is to test it (what SOUNDS like a logical setup may not produce the best results during testing). But just by the parts/fans/orientation you list, you should be in pretty good shape either way if the airflow in your case is not blocked by poorly routed cables, etc. (the front fans should be fine even with the hdd cage...but if you could move it, you may see a slight improvement)

 

[danytancou]

Thanks Matt! Definitely no poorly-routed cables in there.. I'm a bit a**l about that stuff. hehe

Any other opinions/suggestions?

 

[Karadjgne]

Very few choose to mount AIO's on bottom. Not because of hose length, but because that puts the pump at the highest point of the loop. This usually means if the pc is off for any length of time, the pump accumulates all the air in the system, severely lowing ability and running extremely loud until re-primed. Very few also use the side vent with a fan. In your case, since airflow to the gpu is tactically blocked by the hdd cages, your main source of flow is the side fan. Normally, side fans disrupt airflow from front to rear if that flow is stronger than the front intakes.

Personally, if do away with the side fan altogether, or use it as gpu exhaust at very low rpm, and flip the h80i fans to intake. This in effect creates flow from low-front to high-rear in a single function. Right now, most front intake is absorbed by the cooler exhaust, the rest of the pc dealing with intake from the side and exhaust out the top. Basically 2 separate flows.

 

[luckymatt42]

Thanks Matt! Definitely no poorly-routed cables in there.. I'm a bit a**l about that stuff. hehe

Any other opinions/suggestions?

Patience. I know testing and rearranging hardware is a pain in the butt and takes a long time and is not very fun. But you'll have the satisfaction of knowing that you tried and tested and found the best solution FOR YOU. Then come back and tell all us old fogies how wrong we were and have the data to back it up!

 

[danytancou]

Very few choose to mount AIO's on bottom. Not because of hose length, but because that puts the pump at the highest point of the loop. This usually means if the pc is off for any length of time, the pump accumulates all the air in the system, severely lowing ability and running extremely loud until re-primed.

Thanks for that tip Karadjgne! I never thought about that, as I believed AIOs were supposed to be air-free, but I guess that's a perfect world scenario, right? At least now I know why the thing is so loud for a couple of minutes afterI turn it on. I will see if I can maybe mount the radiator at the back, but I think if I do that, it will be more-or-less at the same height as the pump (look at the picture)... It is physically impossible to mount at the top of my case.

Very few also use the side vent with a fan. In your case, since airflow to the gpu is tactically blocked by the hdd cages, your main source of flow is the side fan.

Well, I have no choice there. I need all those HDDs, but now that you mention this, I could move one of them from the upper bay to the lower bay, as they would still be cooled by the lower Front fan. This way, I'll get more air going into the case from the Front top fan.

Normally, side fans disrupt airflow from front to rear if that flow is stronger than the front intakes. Personally, if do away with the side fan altogether, or use it as gpu exhaust at very low rpm, and flip the h80i fans to intake. This in effect creates flow from low-front to high-rear in a single function. Right now, most front intake is absorbed by the cooler exhaust, the rest of the pc dealing with intake from the side and exhaust out the top. Basically 2 separate flows.

Didn't think about the side fan being disruption.. in my mind, as an Intake, it was supplying cool air to the case's entire "main compartment", so to the motherboard overall, to the video card and to the RAM sticks (which simply don't get enough from the Front top intake) and, albeit less, even to the Radiator. Maybe I'm missing something though?

My only issue with flipping the Radiator fans to Intake (and, now that I remember from when I built this thing, why I didn't do it in the first place) is that what they're effectively doing like that, is pumping hot air into the case and, more worryingly I think, onto the video card; "more worryingly" because that hot air is now being taken up by the video card's fans (which of course blow towards the card itself) and that doesn't seem right.

As for having created "two flows" with my current setup, as you say... is there something inherently wrong with that?

Thank you again for the analysis.. and any further thoughts you might have.


Dany

 

[danytancou]

Thanks Matt! Definitely no poorly-routed cables in there.. I'm a bit a**l about that stuff. hehe

Any other opinions/suggestions?

Patience. I know testing and rearranging hardware is a pain in the butt and takes a long time and is not very fun. But you'll have the satisfaction of knowing that you tried and tested and found the best solution FOR YOU. Then come back and tell all us old fogies how wrong we were and have the data to back it up!

For sure! I'll tinker with all this tomorrow and come back with my findings.