PCI intake fans and cooling advice.

After a little high graphics gaming last night I've finally lost my temper with the fan on my Sapphire Radeon HD4870. Over time it has, as is normal with fans, gotten louder and less effective. Currently it is louder than either my airconditioner, the traffic with the window open, the aircraft overhead, and louder than my speaker volume! I don't quite believe that my card reached 105C like HWMonitor suggested, but I do believe it was hot, and I'm inclined to believe that the ambient temperature near the graphics card did hit 55.

My airflow around the graphics card is a problem. in my bitfenix Survivor case I've put a 200mm intake fan on the front (sadly weakened by the hard disk bay in front of it, but I've removed the top bay to give it some hope) and a 200mm outlet on top. I'm a little concerned about the effectiveness of the top outlet not being as high as I'd like. I have my new CPU heatsink blowing upward to, and to its credit it kept the PCU at 50C running max on all core in a very warm case. I suspect there is a deadspot below the graphics card, caused by the card being a big windblock in my case. It doesnt help that this card only has a 40mm radial fan for it's second slot heatsink and duct, and that it's a two way duct that blows half the air back into the case! My PSU is fine since it faces down and draws outside air through a bottom grill. Not quite as good an air supply, but it is at least uneffected by the ambient

What I'm looking for is the following:
a new 40mm fan for the card that is decent and quiet
OR a new 3rd party heatsink for the card, preferably one that will make it a triple slot so it can get a decent sized heatsink.
AND a PCI inlet fan, double slot if need me since all my slots are empty and I have lots of them. I'm half thinking about ducting that onto the graphics card fan to make sure it's only using cool outside air for the card, since it is doing so much to radiate heat into my case.

As you can guess with 2 200mm fans and a 92mm cpu fan I have a very quiet case: with the exception of the graphics card. I'd rather avoid adding more dinky little loud fans, but I don't really want to put too much of a crazy array of things in there.

I'm also considering putting one of my spare 120mm fans into the back, and I'm considering as an intake. Yes my exhaust is at the top but with I dont want to make it suck all the air in my case away from my card. As I have no problems with the cpu I'd rather make the case positive pressure and encourage it all to go out of the intended slots only. Sadly, no one ever thought to put an air filter on the back grill in spite of having filters on the top outlet. I've been wondering for a while: can you buy suitable filters, 120x120, with screw holes that let you just stick it on the back of a fan?

You need to replace that fan on the graphics card first. It is seizing and not moving it's designed volume of air over the card. That may be the extent of your problems.

Current gaming case design requires intake air to enter through the front of the case and exhaust through the back, or exhaust through the back and the top. You want to maintain this design flow. Therefore do not install additional fans in the back of the case as intakes. Turning it around to provide additional exhaust would be fine.


There is a filter that is in front of the front case fans and behind the door frame. If this gets clogged with dust it can really slow things down in a hurry. You need to keep those clean regularly.

There is a limit to what you can do with air cooling. At some point you need to consider water cooling. But if you are not overclocking anything and using a gaming case and your hardware is operating normally the you should be able to maintain normal temperatures using the stock parts.

the issue with the case design is it has a negative air pressure when you have several times as many exhaust as intake. It means that a weak graphics card fan may not be able to force air out against the gradient and ends up with stagnated air. the majority of the airflow is also going up and above the graphics card, well away from it's fan (I really wish they would make a new slot standard for graphcis cards). There is also the fundamental issue of a huge and very effective heatsink for a cpu that uses less than 15W most of the time, and then a tiny fan and small heatsink for a graphics card that pulls over 300W.

It's a new case and the filters are all clean, the heatsinks have been cleaned, the cables are out of the way, mostly behind the other side of teh case under the mobo. The lack of intake in the bottom of the case is a concern to me, and this case doesnt have a side fan. In particular I dont want to be pushing air out the back by the empty PCI slots as they do nothing there but lose me cold air: the only place where air does anything to cool my graphics card is if it goes into the ducted heatsink and out the back by its own exhaust slot. That's why I want positive pressure of cold air right at the fan of the card.

I'm certain the fan isn't sticking, I can hear it's turning. But as usual as it gets older and the bearings dirty the spin is less smooth and less effective. I think regardless of what I do finding a compatible fan to replace that with is a first, although i'd be happier if I could get a larger fan and duct it on to really force the cool air into the card.

I hear what you are saying and it is not a bad idea. You just have to be careful with case modification. Keep in mind that everything is designed to work as a system, and no individual component can truly be isolated. You can get opposite results from a planned design change.

Ducting from the side of the case directly to the intake fan on the video card could have a positive effect. But keep in mind that the power supply and video card exhaust out the back of the case so you may not be drawing cool air from there, but just recirculating the hot air.

The intent of a rear exhaust fan is not to cool components in the (empty) PCI slots. It is to enhance the intake of cool air through the front of the case and direct more air downwards towards the video card instead of directly upwards and out the top of the case.

I have a bottom PSU which takes it's air directly from outside and blows outside, and most of my hot air is going out the top so it's not too bad at the back. It's the gfx card that is hot. If I thought i could get more air from the front I'd do it for sure, but this case has two 3.5" bays of 3 slots each. the top is removable and I've removed it to improve airflow If i could have kept that and removed the bottom I would, because my disks reduce the flow to the bottom of the case. I also have a VERY long graphics card, it's not a small mobo but my card still goes all the way to the point where it blocks the sata ports, and on a previous case I struggled to get the power connectors onto the card because it was nearly hitting the disk bays. This only further blocks the airflow in my case. You could essentially model my case as having a top chamber and bottom chamber with next to no exchange between the two. That's why I want the intake: there is essentially nothing in the bottom chamber as in. To my view the only other option is to bring out the power tools and try and cut a hole for a side fan as intake. I'd rather not start cutting my case up though, and I don't have the tools to do that atm since I'm working overseas and wont be back for a while. my pci blankers have a very slight grill, which only makes me think more about their potential for air flow. it's a very fine grill, fine as a filter, but there is space for practically a 120mm fan there (but that wouldnt put it to the gfx card, i'd need to duct it a little).

really pc design needs to do things differently. Graphics cards are too big and disruptive, only take air from one side, use more power than the whole pc combined and their airflow and cooling is inferior. No matter what I do i've never had problems with CPU heat since the second generation pentium 4 (where they started spreading the heat across the chip), the chipsets are not a problem with heatsinks across the mobo and heatpipes distributing the heat between them. I spent £15 on a arctic cooling heatsink not because of problems, but because after 3-4 years the old cpu fan was dying and the heatsink was blocked in places i coudln't clear. Have to say that £15 does a lot better than the stock cooler, but more than that isnt needed.

I am very tempted by water cooling but only for the graphics card, or possibly my next card if I upgrade in a year or so. The issue is it isn't something you can just dive into, it needs a lot of research and planning first, and I don't even know if you can water cool graphics cards? for now I'll stick to the air cooling that has served me for years, but with all this travelling I'm currently in a country far hotter to normal, and it's starting to matter with old fans.

And for a temporary solution you can do what I do when I don't need to deal with any potential heat issues during an intensive procedure: take the side off the case and run it wide open!

I did think about that, it's quite a pest taking the side off mine (since the protective covers stop you taking the back off) and it'll be loud but it's probably my only short term option until I can find a suitable inlet below the cards. btw, as a measure of the pressures in my case: air is being drawn in slightly from the back of my case, both above my graphics card (where the combination of the top extractor and the cpu fan facing upwards is causing an upflow), and below the graphics card. I would expect, if there was a decent airflow from the front fan to that area, there to be a little air blowing out. I think it's safe to assume that there is next to no air from the front getting to my card. Ironically, while the 200mm fans are really silent and support a larger volumetric flow, the lack of air speed means it really isnt pushing it far enough

True that is.
Some cases simply perform better than others. A true gaming case has plenty of room for the large video cards and good air flow. My case is 21 inches deep.
The hard drives are meant to be cooled by the front fans so don't think of them as in the way.

There has been a lot of evolution in case design and we are not there yet. You correctly point out that there needs to be some coordination between component manufacturers and motherboard manufacturers (and there is), but PCs are not an Apple command economy. Coordination is an elusive goal.

some solo work would help too. A double sided PCB with heat sinks and air ducts on both sides would more than double the effectiveness of cooling. A triple slotted card with a dedicated intake slot and exhaust slot (vectored to keep them apart) would improve a lot of things. The second may be a possibility for me to achieve at least.

coordination is especially hard since it's case manufacturers too. If you want to change the orientation to something like a piggyback board (think one board flat against the other) to enable large, cpu like heatsinks you need a case which lets you fit the connectors at the back, mobos to support it, and equipment manufacturers to make cards for it. It makes sense, given that a gfx card is virtually a motherboard with built on cpu and memory, but it wont happen soon.

Of course when everything has different sizes and weights and heat requirements, the failure of anyone to meet the needs of everyone entirely is not so shocking. Too many combinations.

I guess my best bet is still to find a way to use my PCIs as inlets I'm half inclined, since I have no need for any PCI cards other than graphics, to try and strap a 120mm over the slots and really just use them as an inlet. The hard part is finding a way to attach the fan in place but I'm sure it would outperform anything designed to use 1 slot. I'm still tempted to put a fan at the top back, but I cant really figure on if it should be in or outlet until I know how the bottom back impacts things.

Finally found something that looks like what I need

Antec VCool Review–A Hassle-free Way to Cool the Video Card :: Bjorn3D.com

Nothing spectacular, but since it's a lack of air supply that seems to be dogging my graphics card this may be very effective for the price. Granted it fairly exclusively cools the graphics card but there is relatively little at the bottom of my case, all the heat producting mobo components are nicely in the airflow and seem to be enjoying themselves. Only the graphics card has been suffering in the heatwaves (I'm finally returning to the much cooler English weather again soon), even under load the HDDs stay are 44 and 42 respectively, and CPU I've never gotten the heatsink even to feel beyond warm to touch.

I'm still considering what to do about trying to achieve positive pressure though. I'll take a pick pick and superimpose the airflow paths.

I've never seen one of those in use. Let me know how it works out!

Okay, here is my layout of heat sources. You can guess where my point of concern is and why I want to put the PCI intake in place



here is my approximation of the airflow. Those big 200m fans are quite and have high airflow, but their very low static pressure means that the inward gfx card exhaust distrupts it. most of the cooling flow in the top box is created by the CPU fan more than anything, but most of the heat sources are small and well placed.



I am also considering a 12cm intake on the top back, ducted down below the processor to give stronger airflow on the back of the card and increase the static pressure so it exhausts more effectively. at the very least I'll put a filter on the back hole, enough dust problems as it is!

A couple of ideas. Change the top 200mm to intake which may give you positive pressure and help move the hot GPU air out. Turn the CPU cooler 90° counter clockwise so it will exhaust out the back and take some of the GPU heat with it. If possible, add another fan to the CPU cooler in a push/pull arrangement.

It sounds as if you do need to replace the current GPU fan if it making so much noise. If you're up to it, you could remove it from the card, take off the rubber plug on the fan's bearing and put a drop of lube in there. You can clean any dust on it and the heatsink at the same time.

the gpu fan I will replace anyway, that's a given. it's not that deeply built into the card so it's easy, if i can find the right replacement.

As for the other ideas: I would love to if I could. However, I can't turn the cpu heatsink (I did want it blowing out the back originally, but it doesnt fit, ASUS put lots of heatsinks around the processor to exploit the cpu fan. They are already touching the processor heatink and bending the bottom fin in that arrangement, the side one (hard to see on that picture, but look at any picture ofthe P5Q3 deluxe and you'll se) is about 0.8mm closer, and i cannot get the sink in there.

I hadn't thought of reversing the top fan, I'm sure that would substantially improve the pressure. The problem is that the fan has only got screw mounts on one side of the fan. I'd have to nose around and try to get some long bolts, doable once I stop travelling for work. Not sure it's much use though if the processor fan is blowing upward.

I'm surprised you don't have an exhaust fan on the back.

That's because he has the big fan on the top. which you can't see.

TVeblen said:

That's because he has the big fan on the top. which you can't see.

Click to expand...

I have 2 on the top, and 1 in the back for exhaust. Then again, I have like 2 on the front and 1 on the bottom for intake.

Have you considered a different CPU cooler such as a Cooler Master HyperEVO? It should fit to blow out the back and clear the heat sinks and RAM.
Here's a couple of views of mine (on a test bench). Board is ASUS P8Z68-V PRO/GEN3

The 20cm is just about visible on the picture. I didn't put another 12 in the back because I was moving country that day and didn't have time to get any more parts. I'm likely to put something on the back, just need to decide what.

honestly, the bigger heat sinks terrify me. The idea of putting something that heavy on my motherboard and bending it is something i will never do!. The heat sink I got seems to do an exceptional job and it the lightest on the market save the intel stock cooler. it's just that my motherboard has an annoying number of heatsinks around the cpu (probably to exploit the airflow, but even now they don't get warm) I'm certain I couldn't fit most of the bigger heatsinks, I struggled with my one. my next build in a couple years time I'll be quite careful about heatsink locations I think.

Out of interest....did you seriously build your computer caseless? surely you must suffer from dust (although I get you have decent airflow)

If your case was designed to have top and rear exhaust fans then your problem could be solved by just finishing the build and putting that rear fan in it.
The case designers have a plan that they think will work in all typical PC configurations and you should give that plan a proper tryout, don't you think?

Britton30 does not run his PC with the guts on the table, that is just how a lot of us build a system. Assemble all the important bits on the motherboard and then test it on the "test bench" (which can be a kitchen table) to be sure everything is working properly before putting it all in the case.