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View Full Version : Any reason not to run an open case? (Request for cooling advice)


sillyeagle
02-26-09, 11:52 PM
I've got two 120mm fans, a 79cfm exhaust and a 55cfm intake, and they don't get the job done. Despite the 120mm heatsink fan blowing through the heatsink and directly into the 120 exhaust I get too much heat buildup @ 4.2GHz 1.4v. Due to the size of my Noctua heatsink I am unable to use the 80mm side panel fan, so I'm limited to the two fans. I've got a few ideas but I'm looking for advice from those with cooling experience.

Since my case location is under desk buying another case is not an option, as my Thermaltake Tsunami barely fits, which is not a large case, so these are the options:

1) Install 2nd fan on backside of Noctua cooler. With only a pusher fan the air can disperse a bit before reaching the exhaust fan. With the puller on there as well it should pull all that heat through and blast it directly into the exhaust fan, as the puller would be only an inch from the exhaust fan.

2) Make a baffle to channel ALL air from the heatsink puller fan right into the exhaust. The baffle only needs to bridge 1 inch gap, and this would ensure that almost none of the CPU heat goes into the case, as its funneled right out. The downside to this is that all other heat sources in the case will have to pass into and through the CPU heatsink in order to exhaust, with the exception of what the PSU fan pulls out, so I don't know if this would be a good choice.

3) Buy another 120mm and a mount it on the OUTSIDE of the case cover, over the existing 80mm hole, which I would expand. I would mount in such a way that it blows a solid stream of cold air right into the heatsink intake. Currently my intake blows over 3 HDD's, including a RaptorX, which must certainly be heating my intake air, which makes me think a 120mm blowing cold air right into the heatsink intake would really help.

4) Run with the case cover off, if that is acceptable? This is how I've been running up to now, which works well, and keeps me at 70 on the CPU and 80 on the two hottest cores. I have no problem with this route, though I've always heard comments about making sure your case is sealed with the exception of the fans. I've never understood the reasoning on that, unless its to mean that if you are in fact running a closed case you want the air moving from fan to fan, and not escaping through other holes.

So my question to people with cooling experience: If I combine options 1, 2, and 3 will I be able to run as well as I do with an open case? Or should I just run with an open case since there will be no way to achieve equal cooling with a sealed case and 3 120's?

Hit me with your advice!

BCKator
02-27-09, 02:36 AM
I've got two 120mm fans, a 79cfm exhaust and a 55cfm intake, and they don't get the job done. Despite the 120mm heatsink fan blowing through the heatsink and directly into the 120 exhaust I get too much heat buildup @ 4.2GHz 1.4v. Due to the size of my Noctua heatsink I am unable to use the 80mm side panel fan, so I'm limited to the two fans. I've got a few ideas but I'm looking for advice from those with cooling experience.

Since my case location is under desk buying another case is not an option, as my Thermaltake Tsunami barely fits, which is not a large case, so these are the options:


1) Install 2nd fan on backside of Noctua cooler. With only a pusher fan the air can disperse a bit before reaching the exhaust fan. With the puller on there as well it should pull all that heat through and blast it directly into the exhaust fan, as the puller would be only an inch from the exhaust fan.

2) Make a baffle to channel ALL air from the heatsink puller fan right into the exhaust. The baffle only needs to bridge 1 inch gap, and this would ensure that almost none of the CPU heat goes into the case, as its funneled right out. The downside to this is that all other heat sources in the case will have to pass into and through the CPU heatsink in order to exhaust, with the exception of what the PSU fan pulls out, so I don't know if this would be a good choice.


3) Buy another 120mm and a mount it on the OUTSIDE of the case cover, over the existing 80mm hole, which I would expand. I would mount in such a way that it blows a solid stream of cold air right into the heatsink intake. Currently my intake blows over 3 HDD's, including a RaptorX, which must certainly be heating my intake air, which makes me think a 120mm blowing cold air right into the heatsink intake would really help.

4) Run with the case cover off, if that is acceptable? This is how I've been running up to now, which works well, and keeps me at 70 on the CPU and 80 on the two hottest cores. I have no problem with this route, though I've always heard comments about making sure your case is sealed with the exception of the fans. I've never understood the reasoning on that, unless its to mean that if you are in fact running a closed case you want the air moving from fan to fan, and not escaping through other holes.

So my question to people with cooling experience: If I combine options 1, 2, and 3 will I be able to run as well as I do with an open case? Or should I just run with an open case since there will be no way to achieve equal cooling with a sealed case and 3 120's?

Hit me with your advice!

So, you really have 3 120mm fans? An intake at the front, the cpu heatsink fan, and an exhaust, right? Does your case have a clear or solid side panel? So you only have ~20" under your desk?

With the limited space, I don't think a pull fan on the CPU HS would help a whole lot. I would try the baffle first. Restricting airflow is a good thing if you can force it to go through/over what you are trying to cool. You do, however, have to take into account the other things besides the the CPU HS which need airflow. I would do some experiments and track not just the CPU temps but the temps of your MB, GPU, and whatever else you can monitor as a function of different configurations. I just use construction paper and tape to create what I need.

More air always helps. I think in your case (literally) your problem is the limited air being put into the case. I would add at least one fan on the side. Perhaps if you move them forward you could put them in the case. You could also swap out for more powerful (louder) fans (use 120x38mm if space permits). Just how much room do you have on the side? You can get 120mm and 140mm fans that are only 20mm (.78") thick. You can also get 80mm fans that are only 15mm thick. These don't push as hard as the thicker fans but every little bit helps. You could also cut away the panel that covers the intake fan (very restrictive) and cut away the grill on the exhaust as well (but doing this would involve taking your system completely down).

The main functions of the case are to hold the parts and protect them. As a function of your location and situation, you may not need the protection part and so, perhaps that is the best way to go.

I guess in the end, the answer is "Try it and see".

CaptNKILL
02-27-09, 02:58 AM
I'd say your temps are a way too high honestly. 70C is HOT... 80C is down right dangerous for a CPU.

I'd apply (or reapply) some high quality thermal paste before you do anything else. If you can't drop those temps by 10C or more by adjusting your cooler or applying new paste then you should lower the voltage and clocks a tad.

I don't know if the CPU will actually be damaged at those temps but I'd certainly be concerned about it.

Bman212121
02-27-09, 08:32 AM
I'd say your temps are a way too high honestly. 70C is HOT... 80C is down right dangerous for a CPU.

I'd apply (or reapply) some high quality thermal paste before you do anything else. If you can't drop those temps by 10C or more by adjusting your cooler or applying new paste then you should lower the voltage and clocks a tad.

I don't know if the CPU will actually be damaged at those temps but I'd certainly be concerned about it.

If you're already running 70 - 80C in a free air environment it won't matter how much airflow you have running through the case. It sounds like you're cooler isn't up to the task. Think of it this way, in open air the HSF might be drawing air through the cooler that is a room temperature of 70F. When you close the door on the case, that temperature might rise to say 90F with okay airflow. Even if you had a jet engine pushing air through the computer, the case temps aren't going to be below 70F because that is what the room temperature is. Closing the side panel you have to assume the temps inside of the case are going to go up some, so that might put you at 75-85C with your current config. The only way to cool that processor down is to do something at the cooler itself.

One thing I would suggest though is swap the front and back fans. You need more pressure from the intake if you want better cooling. The PSU, graphics cards, and that exaust fan are all pulling air out of the case, but you only have 1 fan with less airflow bringing in fresh cool air.

sillyeagle
02-28-09, 02:22 AM
Ok this is good stuff. Sounds like I'd be best off remounting the HS, and adding the puller fan while I'm at it. Then I'll test for improvement and decide what to do from there. I've been wondering if I applied too much paste, but since it idles at 32 in a 70F room I figured it must be ok, but in a 75F room I'm at 35 or so, and thats with the case panel off.

The idea about monitoring other components is good, so I'll keep that in mind if I start experimenting. The thing is if my system becomes louder trying to cool it with a closed case than what it is with an open case, I'll just have to leave it open. lol

Thanks guys for reading my huge post and responding. I figured I drew it out to much for anybody to stay interested. lol

bob saget
02-28-09, 05:30 AM
Ok this is good stuff. Sounds like I'd be best off remounting the HS, and adding the puller fan while I'm at it. Then I'll test for improvement and decide what to do from there. I've been wondering if I applied too much paste, but since it idles at 32 in a 70F room I figured it must be ok, but in a 75F room I'm at 35 or so, and thats with the case panel off.

The idea about monitoring other components is good, so I'll keep that in mind if I start experimenting. The thing is if my system becomes louder trying to cool it with a closed case than what it is with an open case, I'll just have to leave it open. lol

Thanks guys for reading my huge post and responding. I figured I drew it out to much for anybody to stay interested. lol

yep

:p

Logical
02-28-09, 11:39 AM
I'd love to see your temps with 20 passes of Linx lol. In all honesty if heat from your CPU is concerning you then you should be thinking more about backing that o/c off a little. I run my core I7 920 at a 3.6 Ghz 24/7 oc. Under normal load use i never see the surface temp go above 50c or 60 on all cores. With stress tests i see a rise in temps for obvious reasons but surface temps would go to 70 and core temps upto 80c.

My 4.0Ghz profile is a little higher at 75c surface temp and 90c on all cores in 2 hours of Prime95 or 20 passes of linx.

Your CPU is at normal temps at those overclocks imo...run prime95 small fft's or try using 2- passes of Linx and report back with temps. Also can you let me know what your voltage regulator temp is under load with prime or linx.

Zelda_fan
02-28-09, 12:14 PM
running an open case will collect dust like a mofo