Maximum PC

I have my cpu fan, and 5 fans around my pc:

3 IN fans: back bottom and front

2 out fans: top

I have the 2 top fans and the bottom fan on a controller, which was more something I wanted to do than needed, I'm not overclocking or anything like that at this point, if anything I felt like I wanted my gpu to be cooler, it idles at like 51-54 C. Anyway, the fans even up all the way, don't really make a difference, but I was wondering if that setup was reasonable. The top two fans are covered with a mesh that came with my case, I was wondering if I should still have that on, even if those fans are blowing out. I was considering flowing air in through the top also, but I thought maybe that mesh would make the air flow less in that case.

this is my case:

http://www.newegg.com/Product/Product.a ... 6811121096

First, the important thing to consider is the amount of air being pushed by your fans. You want more air pulled into the case than pushed out, generally.

When the amount of air pulled into the case exceeds the amount of air being pushed out, positive air pressure will help exhaust air from the case and will ensure that you are controlling the air flow.

If you aren't seeing a temp difference, it means that you are circulating air about as well as you can .. or it means that you have a deadzone around your GPU. This is very possible given the configuration of most PCs .. GPUs often have a deadzone around them with little/no air movement.

Additionally, positive pressure helps keep dust out of the case as long as the intake fans have filters.

well only my bottom intake has a filter. Ideally I would like to pull air in through the top and back (and maybe bottom), and push it out through the front 1 (2if I rig another sometime) (and maybe bottom). Meaning the bottom could be either, I doubt it does much anyway unless I boost the tower up.

I say ideally meaning that would blow air at my gpu from sides, and have 3 fans blowing on my cpu. That doesn't mean what I think is ideal is what's best.

The problem is I feel like I need a fan blowing on my hard drive, which is what my front fan is doing now. My hard drive has no heat problems to my knowledge, but I just feel like that's the right things to do...?

Another fan in front would take up bays, but probably bays I will never use, and I would have to rig it.

Is 51-56 hot for gpu idle, i'm sure it heats up while gaming also.

That really depends on the GPU.

hfx 5770 hd?

Yeah, that is warm for idle.

Not dangerous, but unusual.

Mine idles in the 30s.

What does it hit when it loaded?

pry like high 60's, but I haven't loaded it with anything higher than starcraft 2 beta on highest settings for like an hour. I just started my computer up, and started Catalyst and it said 50 C right away and says 55 now. 50 C right after startups seems a bit much. I don't know if I have ever seen it below 50 either. The GPU is my main concern. CPU hangs around 40. System temp hangs around 44.

Not sure I understand your logic here Spartacus...It shouldn't make a big difference if you have a positive or negative pressure. Most PC cases don't have too many open spaces that lots of dust will come in. Not to mention that it would take a very negative pressure to create enough air flow through a crack, hole etc to suck much dust in.

IMO, lots of cool air flowing through the case and around your hot components is the key. You want your in and out to be balanced so that you have a neutral pressure in your case. Ideally, I think you want a neutral pressure so that your fans aren't fighting each other, thus giving optimal airflow.

Also, you should try to set up your fans so that all the air flows one direction. You don't want two front fans pulling air in, just to be pushed out by the third front fan.

Also, keep in mind that hot air rises, so pull air in at the bottom, exhaust out the top. Generally, you also should pull in cool air from the front to blow over cooler components like the HDDs etc and then get exhausted out the back as it warms up blowing over the CPU etc.

Depending on your GPU heatsink (does it exhaust out the back of the case or just back into the case?) you'll want a side fan blowing cool air on it, or pulling hot air away from it (also depends on how many other fans you have pulling air in).

In my rig, I have a single 120mm front fan and a 250mm side fan blowing air in. The 120mm front fan blows cool air on the HDD. The side fan blows cool air all over the mobo, CPU, GPU. Pulling air out is my 120mm exhaust fan, a 140mm fan on my PSU, and my GPU HSF. Pretty sure I have a negative pressure in my case and I don't have problems with dust at all (mostly cat hair sticking to my fan grills of my intake fans ).

Compare that to an old dell that has a single fan exhausting (and PSU fan exhaust) and no grill or filter over the intake. The damn thing collects tons of dust. Moral of the story-use dust filters, fan grilles etc.

Also, they sell PCI fans that fit in a PCI or PCI-E slot in your mobo and can blow cool air or suck out warm air through an addon card slot.

Here is a drawing I quick whipped up for my case.

Blue is IN fans

Red is OUT fans

The thin red arrow is my GPU exhause (I think it is out the back)

The thin red rectangle is my psu fan, which I did not know worked as an exhaust until now. I thought my psu was solid on the bottom, in fact I kind of still think it is, but I should have a look when I get home.

Notes: all designated fan spaces on my case are covered in fans, so that's where those are located. There might be enough room in between the fan speed controller and the bottom fan for another fan if I rigged it, but I don't think it is meant for a fan, and it might take away all or all but 1 of my remaining bays to put a 120 mm fan there. And I would have to order another fan.

The only fan with a dust filter on it is the bottom fan next to the psu, as it is on carpet.

the gpu fan is on the lower side, and the board is on top in the pic



Looking at this now, it seems dumb, but how would you guys suggest doing it, keeping in mind that another fan could be an option. My GPU idles around 55 C, my cpu around 39 or 40 C, and my system temp around 44 C.

Have the rear fan exhaust as well and you'll have decent air movement.

That's not quite true. A lot of modern PC cases, and especially OEM cases, have tons of passive vents. If there is even the slightest negative pressure (like in OEM cases that just have a single 92mm exhaust fan), then tons of dust gets sucked through the vents. I see that so often. A case with just a single exhaust fan is overheating because the vents are clogged with dust.

You don't want a lot of pressure one way or another. Whether positive or negative pressure cools better varied from machine to machine, the difference is never worth the trouble of ensuring that the pressure is one way or another. But the difference in dust intake is definitely there. My last case was a Logisys Area-51, which I set up with one more intake 120mm than exhausts. I had to clean it out maybe once every 4 months. A month ago I got an NZXT Tempest EVO, which has slightly more exhaust than intake. All the vents and intakes are filtered except one, and the case is already full of dust and the filters are clogged. Again, it just varies from case to case.

all good thoughts thank you, I think i was too focused on blowing air on my cpu and gpu and not enough on air flow as a whole, fair assessment.

someone noticed my psu might be top vented, and blowing hot air on my gpu, so i might check thought and try to route the psu air flow out the back somehow.

lastly, if the positive to negative thing bothers me after turning the back fan around, I could put an extra IN fan in front, or move one of the top OUT fans to a front IN fan, good idea?

Yes, the problem with intake in the rear, is it will be sucking the hot exhaust air from the PSU and Video cards that are pushing theirs out the back.

Your stated temps are absolutely fine. In fact way below even remotely concerning levels - let alone the panic you seem to be expressing. Unless you start doing something funky with this system, there's no need to drive your temps down any lower.

and as Spartacus says, I haven't seen a case in years, at least over a decade, that doesn't have some additional ventilation slits, mesh, etc. in it. As a minimum, around the I/O or the PCI areas of the back panel, but also on the lower part of the front/side panels.

Mine is just the same. Haven't had a problem. Just make sure your load temps are low - mine loads at ~80C. HWMonitor will display the highest temp your GPU reached.

The discrepancy between Jipstyle's temps and your temps might be that you're running Aero in Windows and he's not. (Aero keeps the GPU slightly active.) Not sure if he's enabled it or not so perhaps he can chime in on that.

I'm not THAT concerned, I just felt like the GPU temp was a little high, and someone said they tought maybe my psu (OCZ 550W Fatal1ty) was struggling to power my stuff and the GPU was heating up, which concerned me, but it's more just something I wanted to do. I would like to have a case that is set up in a way that works well, even if it isn't necessary. But either way thank you guys for the input. Very helpful.

Check which direction your CPU HSF is blowing air. With your configuration of exhaust fans on top, you probably want to blow air over the HSF up and out of the case, although to the back to get exhausted by the rear fan would be ok too if the HSF won't fit the other direction.

Also, if you are going to add another fan, I would recommend adding one on the side of the case to blow cool air over the GPU, as it looks like (and from your temps seems like) there may be an area without much air circulation.

Two other things kinda off topic... I don't like bottom mounting the PSU because it can contribute towards a sort of dead spot of air around the GPU. Also don't like GPU HSFs that blow warm air back into the case. All GPU HSFs should simply exhaust all hot air out the back of the case if it's a double-slot cooler.

The bottom-mounted PSU system works fine if there are vents on the bottom so it can be mounted right-side-up.

I fan on the psu blows down and exhausts out the back, I might turn the psu upside down anyway so that it is pulling air from the bottom and boost the case, then put a fan blowing on the gpu through my open pci slots, or just another in the front, I might just order another couple cheap fans and work around with them.

If the case has a vent under the PSU, that's fine. Otherwise, you're asking for trouble because you'll completely suffocate the PSU.