In-case air flow

[Epical]

So, I just finished building my new PC last night, and in trying to keep my old one up-to-snuff, I decided I'm going to OC my CPU in it. Thing is, the CPU cooler (Scythe Ninja 2) isn't the best, but can definitely handle an OC (factory 2.4, want to push it to 3.0). I went out and bought a 110 CFM 120mm fan to replace the ~30-40 CFM fan it came with to help move a lot of air. Then I had a thought... what is the best way of managing airflow?

I drew a couple (horrible) sketches of what the towers air flow looks like and what I think would work (better?):

This is what both towers have right now. My old case is an Antec P180, the new one an Antec Nine Hundred:
http://www.bluegartr.com/gallery/epical/1233093007.jpg
(Obviously the 200mm fan is the Nine Hundred only)

This is what I would THINK would improve air flow in my old case (leaving the Nine Hundred as it is -- the Freezer Pro 7 will be fine):
http://www.bluegartr.com/gallery/epical/1233093014.jpg

Basically I'm inverting the top 120mm fan so it's drawing cool air into the case and the high-flow CPU-mounted 120mm pushes alllllll of that out the back. Good idea? Suggestions?

[Blabj]

You'll create a lot of dead, warm air around the back of your graphics card if the fans are running too hard.

The general idea is the cold air is drawn in from the front of the case near the bottom, and rises up the case as it hits the various components within the case, eventually reaching the top of the case where it can be vented very quickly from around the CPU.

This is the theory, however, and assumes perfect air flow etc. (which in the real world never happens, due to cables and other obstructions) so by all means try out your idea, it might work!

[Cephius]

In my humble opinion, its more about pulling hot air out than it is pushing cold air in. Bringing colder air into the case does no good if you're not moving the hot air away from the processor and components. I'd suggest keeping it as it is... back fans and top fan sucking hot air out, while colder air is brought in at the front.

[Isiolia]

I think if you look at it in terms of airflow through the entire case, not just around the CPU area, it makes more sense to have the top fan be an exhaust.

[Epical]

Hmm, ok. I just thought the high-flow fan mounted right on the heatsink would've made good enough in taking care of all the air in that area. Also, I don't believe there are any front-mounted fans in my P180... just the exhaust fans that are sucking out ambient hot air.

Cable management is my weakest point, by far... biggest clusterfuck ever in there so I'm sure that isn't helping things at all.

I'll keep it as is then, thanks for the input.

[Amastacia]

You absolutely want the top fan as an exhaust vent.

First and foremost, it's going to be exhausting some of the hottest air in the case (air that has absorbed heat from some of the motherboard components and CPU, but hasn't been directed at the rear exhaust fan by the CPU fan).

Secondly, and tangential to what was mentioned above, it's going to cause more harm than good because it creates turbulence. The natural airflow (especially in Antec cases, which have quite a bit of thought put into them in that regard) is front-to-back, and having the top rear fan blow air in is going to create currents that make it harder for the CPU and rear exhaust fans to work.

The nice thing about most Antec cases (the P180 and 182 especially, haven't used a 900 to see how it compares) is that it's pretty reasonable to route cables such that the impact on airflow is minimized. You're not getting quite the "ideal" flow, but it's actually pretty close. Thus, the argument about preserving front-to-back and bottom-to-top airflow holds up well, and will yield the best results.

I thought about doing the same thing (briefly) with my P182 until I really started paying attention to my system temps, and also seeing just how hot the air the top exhaust port is (mainly when my calves got very warm because the case makes a great footstool).

Edit:
Epical posted again and I didn't see.

Doesn't the P180 have the same behind-motherboard space as the P182 for routing cables if they're long enough? I mean, yeah, I have a small snarl around the SATA ports on the motherboard, but you can still get pretty tricky with how you route and hide cabling to reduce the impact. The P182 build was by far the slowest I've ever had to do because of the time it took to get really slick with cable routing, but the airflow in the long run was well worth it.

[Shadowhusky]

In case you forgot, here is a little science lesson. Hot air rises, so of course you'll want the top fan blowing that hot air outside.

[Epical]

I know this isn't part of the original topic, but I'll just post it here instead of making a new thread:

About to start up new rig, there is one 500GB HDD in there, should I partition 100GB to C:\ and the remaining amount to data (games, movies, music, etc)? My existing PC has one massive C:\ drive and I've always thought I could've done it a bit better.

Yay? Nay? Thanks again.

[Shadowhusky]

I know this isn't part of the original topic, but I'll just post it here instead of making a new thread:

About to start up new rig, there is one 500GB HDD in there, should I partition 100GB to C:\ and the remaining amount to data (games, movies, music, etc)? My existing PC has one massive C:\ drive and I've always thought I could've done it a bit better.

Yay? Nay? Thanks again.

Why not just get another 100GB+ HDD? They're not all that expensive anymore.

[Norellicus]

I know this isn't part of the original topic, but I'll just post it here instead of making a new thread:

About to start up new rig, there is one 500GB HDD in there, should I partition 100GB to C:\ and the remaining amount to data (games, movies, music, etc)? My existing PC has one massive C:\ drive and I've always thought I could've done it a bit better.

Yay? Nay? Thanks again.

You'll get better efficiency as far as GB availability if you split it up, but it's a headache when you suddenly run out of space on one of your partitions and find yourself having to resize stuff; personally I'm willing to lose a chunk just for simplification's sake, also helps some of my legacy games not spaz the fuck out when I try to run them from my J: drive or some shit.

90% of windows apps are still going to consume a surprising amount of space on your C: drive even if you specify to install them to another partition, due to shared files or core files that have to be put in a specific location, so even though you might think "But 100gb is so huge, how could that ever run out"...believe me, it can.

[Epical]

Ended up going with 100GB C:\, 35GB Windows 7 (W:\), ~365GB Data (K:\). Should work swimmingly.

[Spekkio]

The Heatsink Guide: Case Cooling

i fear that if you go with your original configuration, you're going to have the 4th picture of an airflow short circuit causing inefficient cooling. in order to ensure i get good cooling, i always like to think of 2 airflow paths in the case. if facing the motherboard tray, the source of both paths is the lower right corner and the ends are at the GPU fan(s) and the CPU fan(s). place a high airflow fan by the hard drive rack as your source and balance your outflow fans to eject about the same chunk of air.

remember, airflow in must equal airflow out or your 110 CFM fan won't push nearly so much air. it will be like those juice boxes you had as a kid where they would regularly flatten themselves while you drank them b/c you were applying more suction to the straw than air could seep in around the straw.

one last comment, never place your hard drives in adjacent slots when you have the option. yes, it makes the cabling a hair easier, but when you do that, you're effectively taking away almost half the surface area of the drives for heat dissipation (since the underside of the upper one is so close to the top side of the lower one) and forcing your drives to run hotter. to extend the lifespan of your hdds, keep them spaced out. another advantage of ensuring that your airflow starts at the hdds, you ensure that they're kept the coolest of everything in the system. if you lose your cpu or motherboard to overheating, that's bad. transfering that heat to your HDD and shorten the lifespan of it or even cause it to fail with important data on it though, is a cardinal sin.

[Reality]

i bought a lian li A05 case (one of the smallest cases around that isn't a mini/micro-atx case), and unfortunately it only has room for 4 3.5" drives, and 2 5.25" drives, and i'm currently using all 6 up

these cases are very small, and unfortunately almost need an h2o setup to properly cool your cpu/videocard, because of the way the case is designed (motherboard is mounted upside-down, and on the opposite side of the case, power supply sits on the bottom of the front of the case, which is where the exhaust is, intake is in the rear of the case)

i love the case though, but be sure to think your build through before purchasing

http://img149.imageshack.us/img149/3184/img1405se4.jpg

[Shadowhusky]

I'll hijack this thread instead of posting a new one. I bought a new case last month (Newegg.com - COOLER MASTER COSMOS 1000 RC-1000-KSN1-GP Black/ Silver Steel ATX Full Tower Computer Case - Computer Cases) and my question is this. From the pictures you can see all the HDD bays are really close together, which leaves little to no room for air to circulate though. There's no front case fan to blow air on them, just that bottom fan in the photos. Which does not blow air at all on the HDD's. But the thing is, since I replaced all four fans in the case, when ever I stick my hand in there with the side panel on, it's very cool inside the case. Is there really anything more I can do to keep my HDD's from getting too hot? Since I can't put a front case fan on.