Air flow advice

Okay, I've been having random crashes for a while now and it's finally gotten to the point where I want to fix it. My suspicion has always been overheating as it tends to happen after fairly long sessions of gaming.

My case has 3 mounting points for fans. One in the front, one in the back, and one on the side directly over the CPU. My question is what would be the best way to setup the air flow? Obviously I want atleast one fan sucking air in and another pushing air out. I put a 120mm fan in the front for pulling air in and I put another 120mm fan in the back to suck the air out. The side fan I wasn't sure about. I currently have an 80mm fan setup to suck air in because I figured it would be better to have 2 fans pulling in the cooler air and 1 pushing it out. But now I'm wondering if I should have 2 fans pulling out the heated air instead.

I'll probably end up just trying it both ways and watching my temperatures, but I was curious what some of your opinions would be or even what type of fan configuration you guys used.

Rumor has it higher input = more pressure on the inside = dust gets pushed out. Lower pressure on the inside means dust gets pulled in. Not 100% sure about this, but I have heard it a halfdozen times over the years.

edited: my reading comprehension sucks today

My only suggestion would be to point the side fan in if it's immediately over the video card. It dropped the temps on my card in a previous case by a couple degrees. Other than that, it sounds like you're doing the right thing in testing both configurations.

Most setups I've seen have the front and side fans sending air in, & the back fan pulling it out.

I never thought of this before, but most cases are probably chaotic whirlwinds.
Side fan: In at VidCard(which is typically close to CPU)
Vid Card Fan: Up towards PSU, probably?
CPU: Exact opposite direction as Side Fan, but staggered up and forward a bit?

Then add at least one front fan in and one back fan out and it just sounds like it'd be hard to determine actual airFLOW.

You could always sleeve/vent/pipe/whateverit'scalled your video card.

Your fans sound fine with the front-in, side-in, rear-out. If your problem is CPU temperature, I'd check to make sure you have a good connection between the heat sink and the CPU. Many older and OEM heatsinks are not flat on the bottom, leading to poor cooling performance. Another common problem is either too much thermal grease, or a thermal pad that isn't positioned correctly - both of which can be solved by stripping off the existing thermal material and setting up the heatsink again with the correct layout - a very thin layer of thermal grease and a properly lapped heat sink.

I have a PC-7Aplus from Lian Li. I have two intake fans in the front, both 120mm (one where the 5.25" bays are, one in the normal intake position). I have two exhaust fans, a 120mm and a squirrel-cage on top of the video cards. The CPU cooler is a Zalman 7000Cu. In an 80F room, it idles at 41C CPU and 45C motherboard (Asus with passive cooling on the chipset, with the heat sink right under one of the video cards), and with BF2 running full blast I might make it up to 53C/58C - my video cards put out a LOT of heat. In a 70F room I never make it over 50C.

Also run memtest86+ on your RAM if you haven't already. Aside from heat, your next three biggest "random crashes" are bad RAM, motherboard going south, or a failing power supply.