Airflow question

[noteworthynerd]

I recently picked up a new case, went with the Arc Midi by Fractal Design... I got everything switched over last night, but I wanted to double check on my fan setup... Currently, it looks like this:



Is this optimal? I've read that you have to make sure that air intake and exhaust are equal, or it messes with the air pressure inside your case. Unfortunately, the front and side panels only fit 140mm+ fans, so I had to swap the 140mm fans that came installed on the back and top panel with 120mm fans (which I ordered with the case because I thought NewEgg said a 120mm fan would fit on the front)...

It is especially important that I get adequate airflow because I've got my two 560Ti(s) nearly (there's about 1/2 inch gap between them) sandwiched together due to poor motherboard design. I did remove the bottom hard-drive cage so that it wouldn't block the airflow coming from the front fans.

[BicycleMafioso]

You don't need equal intake/exhaust.

But positive pressure is preferred to negative, so have more intakes than exhausts.

[noteworthynerd]

Thanks for your reply! I assume since I've got three 140mm fans intaking air and only 120mm exhausting air, I should be okay?

Also, if I could get some input on my SLI setup that'd be great. I would make a new thread, but I don't want it to seem like I'm spamming the forum...

This is my current setup inside:


As you can see, the GPUs are nearly touching each other, and it is making me nervous (last night I did a quick test, and the top was running ~7-9 degrees hotter than the bottom card, and that was just sitting at the desktop). Unfortunately, I can't move the second GPU to the bottom PCI-E slot because the PSU is in the way... I did plug the monitors into the bottom GPU, hoping that it would make the bottom one the "main" card, but I don't know if that's how it works...

Do you think I'll be okay? I really can't afford a new motherboard with better spacing because I've already poured way too much money into my computer this holiday season.

[Cantii]

You'll be fine as far as your video cards are considered. However, if you want, remove the top hard drive cage and it'll improve airflow and should lower temperatures a degree or two overall, including on the top video card. Or, if you can find a way, mount a 120mm fan on the side of the HDD cages (might take some creative zip-tying!) As long as the top GPU stays under 90C, you'll be fine -- it's perfectly normal for the top GPU to be as much as 12C hotter than the bottom when they're that close together.

As far as overall airflow goes, I am a huge proponent of positive pressure. Even pressure is fine, but for optimum cooling, positive pressure is the way to go, IMO. It also depends on the type of CPU cooler you have and the positioning of the cooler in relation to the top fans. If you have a tower cooler, you could very well flip the top-front fan to intake and actually remove the top-back fan and actually block the vent, which would force all air out of the rear exhaust, as well as any opening as well. Having the top-front fan as intake with a tower-style cooler, assuming the positioning is right, lets that fan blow air straight down into the path of the cooler, allowing it to have better access to cooler air. Blocking off the top-rear vent helps keep pressure positive and creates more of a wind tunnel effect (which is what you want).

What type of cooler are you using and what fans, aside from the stock FD Arc Midi fans?

[noteworthynerd]

I'm using the stock cooler that comes with the i7 950.

I'm also using two SilenX EFX-12-15T (the back panel and top-front) that I bought when I ordered the Arc Midi and one Thermaltake DuraMax 12 AF0060 (top-back) that I pulled off of my old Thermaltake case.

I should add: the case came with a fan controller for up to 3 fans that I didn't plan on installing, would it be better if I did and cranked them all the way up? And if so, which ones should I attach to it?

[Cantii]

Honestly, if you're using the stock Intel cooler, I would turn both top fans as intake, just to get more cool air down into there. Especially since your video cards are eating all the cool air being blown by the side fan. Leave your one exhaust, you should notice temperatures drop overall.

Only use the fan controller if you're worried about noise. If noise is a concern, then just put your loudest fans onto the fan controller so you can keep the noise down. Other than that, if it's not a concern, just leave it out.

[noteworthynerd]

One 120mm fan will be enough to exhaust all of that air?