Airflow and cooling questions.

D

Digitoxin

n00b
Joined
Feb 11, 2006
Messages
29
I need some answers and advice about my setup because either I'm doing something really wrong or the people I'm talking to are full of it.

My system is as follows:
Motherboard: ASUS P5N32-E SLI
CPU: Intel Core 2 Duo E6400 Overclocked from 266x8 to 333x8.
Video Card: BFG GeForce GTS-250
Case: Coolermaster CM690
Hard Drives:
2 Seagate 1.5 TB 7200.11
1 Seagate 500 GB 7200.10
1 Seagate 400 GB 7200.10

I have the following in my case for cooling:
1 120mm intake in the front running at approx. 1962 RPM.
2 120mm exhaust on top of the case. Both running as approx. 1875 RPM.
1 120mm exhaust in the rear, running at 1500 RPM (This is a 2000 RPM fan, but the motherboard doesn't seem to run this fan at full speed)
1 120mm intake on the side panel running at 1300 RPM for cooling the expansion bays.
A Coolermaster Hyper TX3 cooling the CPU. The fan it comes with runs at 2800 RPM and blows towards the back of the case where the rear exhaust is. I have added a second fan to the cooler which is blowing in the same direction and runs at about 1800 RPM.

I have tried adding another 120MM intake to the side panel but it seems to intefere with the CPU cooler and actually causes the CPU temperature to rise. Does this sound correct?

The following are the temperatures I am getting inside the case:
The video card idles at 48 degrees.
All 4 hard drives idle at around 40 to 41 degrees.
I'm not sure what the cpu idles at right now. I am running Prime95 at the moment and with the CPU overclocked, both cores jump between 62 and 68 degrees at full load according to Core Temp.

From what I've read on the internet in multiple places all of these temperatures should be lower for my setup. I cannot seem to find a straight answer anywhere on whether or not my temps are too high or fine for my setup. Am I wasting my time worring about this or do I have something to worry about?
 
is there anywhere you can add more intake fans besides the side panel (since it seems to interfere with the cpu heatsink)? if not it might be time to bust out the dremmel tool! lol
 
Software temperature readings aren't too accurate, the best way is to get out an actual thermometer and measure the temperature of whatever parts you can measure.

Also, what are your ambient temperatures? That plays a huge role in what temps you are getting.
 
Digitoxin said:
I have tried adding another 120MM intake to the side panel but it seems to intefere with the CPU cooler and actually causes the CPU temperature to rise. Does this sound correct?
Click to expand...

I have seen this before, it seems that if the placement is wrong the side fans air intake disrupts the natural front to back flow of the case and causes the CPU fan to not get as much cool air as it should. Basically you are causing air in a strong flow to cut accross the intake stream of the CPU fan thus disrupting the flow.

The HD temps seem a little high but otherwise I am not seeing anything there that looks that far out of whack. Then again I never run more than 2 HDs so depending on how you have them placed that could account for the temps.

As mentioned you need to give us the room temp as well that this is being tested in, that can have a serious impact on the component temps. Also do not could your current listed temps as correct idle. You have the CPU, RAM and motherboard under load as you mentioned, this means there is a natural heat increase within the case right now. Idle temps are only accurate if you let the PC sit unused totally for a decent period of time, say 30 minutes.
 
My suggestion would be to
1) Remove the forward top exhaust fan and block the hole. This should force the internal air flow further back, providing more air to cool the CPU.

If that's not sufficient:
2) Speed up the front intake fans.
 
Ambient temerature in the room is 25 degrees when I'm home and 26.5 during the day. I live in Miami and it is pretty hot and we don't turn the thermostat down too much to save on electricity.
 
The CPU fans are situated so they blow right across the heatsink and straight out the back. I've never used a cooler like this until now, but this seems like a very effective solution to get the heat out of the machine. I think my problem might be getting more air to the other side of the CPU fans so they has more to work with. I am going to try to install another intake fan on the bottom of the case. My case is sitting on a rack stye shelf so there is nothing blocking the bottom of the case.
 
The following are the temperatures I am getting inside the case:
The video card idles at 48 degrees.
All 4 hard drives idle at around 40 to 41 degrees.
I'm not sure what the cpu idles at right now. I am running Prime95 at the moment and with the CPU overclocked, both cores jump between 62 and 68 degrees at full load according to Core Temp.

From what I've read on the internet in multiple places all of these temperatures should be lower for my setup. I cannot seem to find a straight answer anywhere on whether or not my temps are too high or fine for my setup. Am I wasting my time worring about this or do I have something to worry about?
Click to expand...

For a warm room say 80F or more, hell no, you are perfectly fine. There is nothing at all wrong with those temps and the cpu temp running Prime is excellent. ( the OC is medium, not ragged edge and about exactly what I would expect) . If you said it was 70 and the AC was on then I would say they where a bit higher than I expected.

Play around with the fans if you want, it can be fun, see/think about wire management if it looks like crap etc. But no, you have no cooling issue at all, but there is always opportunity to experiment/improve if you feel like it.

Do run something like 3d Mark if you are a gamer to see where your video card tops out in temps (or just play your favorite game) that would be the component I would most worry about reducing the heat on. Kicking off prime and then 3d mark will bring your machine to its knees but will give you a better indication of what worst case actual case temps would be as the video card, even if it dumps its exhaust out the back slot will still help heat up the case interior if it runs in 3d very long.

oh, almost forgot, yes the people you are talking too are full of it, myself included.
 
Last edited:
Here is a shot of the inside of my case. I recently added the intake on the bottom. This would have never fit if I didn't have the modular power supply and even then, it was a very tight squeeze. I now have 3 intakes. One in the front which you can't see in the image. It is blowing across the 4 hard drives. The new one is on the bottom and there is one on the side panel which blows across the expansion cards. There are 2 exhaust fans on top which you can't see in the picture and 1 in the back. All these fans are 120mm. The 2 fans on the CPU cooler blow towards the back. I have no clue what to do with the ribbon cable for the Sound Blaster X-FI front bay. Currently it is blocking some of the air flow from the bottom fan. All fans are attached to the motherboard so I have full control over the speeds. When I bought this motherboard I never thought I would use up all of the fan headers. Guess I was wrong!

CIMG2132.jpg
 
First of all, your temperatures are fine as they are. The only reason to try to get them lower (as long as you're happy with your overclock) is really just for the sake of getting them lower.

Second, I'd seriously consider spending some money on a power supply before I bought any new fans or heatsinks.

With that said, you're probably wasting your time with the case fans. Airflow in the CM-690 with all of the top/rear fan mounts occupied with exhaust fans and the single intake fan over the hard drives is excellent, and you're not likely to see much improvement in ambient temperatures in the case, unless the fans you have are absolute trash (though "absolute trash" is a pretty apt description of the stock fans, and coolermater fans in general...). The Phenom system in my sig is in a 590-which is smaller than the 690 but has a very similar fan configuration-with a bunch of low speed 120mm fans and it has no heat issues of any kind; my case temperature is basically whatever the ambient temperature of the room is.

Adding the bottom intake may help though; in a case that's set up for decent airflow with slight negative pressure (of which the 590 and 690 are excellent examples), trying to equalize the intake and exhaust airflow is, in my experience, largely pointless, but it might get more air moving across your video card, which won't hurt a thing. Your hard drive temps are a bit on the high side but that's due to the design of the 690's hard drive cage and without going to an extremely loud, high speed 120mm fan to cool them there's not much to be done about it. They're in spec, so I wouldn't worry about it.

Don't bother putting a side panel fan over the CPU heatsink; as you've already experienced it's more-or-less a waste of time.

Your CPU temps are nothing to worry about, but they could be cooler than they are (although not necessarily with that heatsink...). You could probably squeeze 3-5, maybe (and I stress maybe) as much as 10*C or more out of the TX3 if you strapped a sufficiently high airflow fan (i.e. this, this, this, or this) to it, but unless you're deaf you'd probably be better off just buying a better heatsink. This one would be ideal, if you're OK with dropping $80 on a heatsink and fans that you don't really need. If not, this is $40 ($25 w/rebate) and it's quite a bit better than the TX3. There are other heatsinks worth considering-the Prolimatech Megahalems, and the Thermalright Ultra 120, for instance-but both of those come without fans and they cost about $50-60. Given that a decent 120mm fan costs $15, you might as well just go the Noctua route at that point since it comes with OK fans and it'll outperform everything else, including some watercooling kits.
 
Your airflow looks fine. Basically, what you want to try to do is match the CFM of the intake fans combined with the CFM of the exhaust fans. Your hard drives are running a bit warm, I would try to get a more powerful fan in front of them.

I'm not sure what you can do with the ribbon cable, your best bet would be to try to turn it on its side. Otherwise, I think you're fine, and a single ribbon cable is not going to impede your airflow that much.
 
The power supply is fairly new. Is there something specifically wrong with this model that I should know about or do you dislike Ultra models in general? The CPU heatsink is also brand new. Because of budget constraints, I get what I can afford. I got the heatsink for $20 and I already had the second fan to attach to it. Yes, I'm using cheap coolermaster fans, just not the ones that came with the case. They were too slow. All of my 120 mm fans are running at 2000 RPM. What is the benefit of higher quality fans? Do they have more fins, are they faster, or do they just last longer before they need to be replaced?
 
Also, since I no longer have an intake fan on the side panel near the CPU, would covering up the spot where the fan goes help with the airflow in the case or would this not make much of a difference?
 
I have the same motherboard you do, and I have a Q6600 B3 on it, overclocked to 9x 333. My case is not the same, but pretty similar after some mods. My room is about as warm as yours, usually a little warmer. I think your temps look pretty good. Mine are a bit lower than yours, but they were a bit higher than yours until I made one extra change.

I added a duct from front to back. Right now it is a piece of cardboard, folded into a U that is wide enough to straddle the rear exhaust fan and the heatsink, and deep enough to just touch the motherboard on both sides, and long enough to butt up to the hard-drive bay in the front and the exhaust fan in the rear of the case. This keeps the CPU, RAM, and chipset somewhat isolated from the warm air in the rest of my case (and the neighboring 5870).

I don't have a picture of it, but the duct is where the white lines are:
2rmwf40.jpg


I have, like you do, two fans on my heatsink. The second fan is not pictured, but zip-tied onto the heatsink. So, total, I have 4 fans moving air: the front fan in the CM hard drive bay, the fan on the outside of the heatsink, the fan inside the heatsink, and the rear exhaust fan. The duct keeps all those fans working together, and little to no turbulence. Even with all 4 of my hard drives in that bay, the air coming off of them toward the heatsink is cooler than the rest of the case air. You should be even better off since it looks like your drives fit in the bottom bays.

I have a big fan on the side panel and a blowhole in the top that keeps air moving through the rest of the case, but those don't affect my CPU much, if at all.
 
Digitoxin said:
Because of budget constraints, I get what I can afford. I got the heatsink for $20 and I already had the second fan to attach to it. Yes, I'm using cheap coolermaster fans, just not the ones that came with the case. They were too slow. All of my 120 mm fans are running at 2000 RPM. What is the benefit of higher quality fans? Do they have more fins, are they faster, or do they just last longer before they need to be replaced?
Click to expand...

I hear you on the budget angle. It's why I modded my Centurion 5 rather than get a new case. As for fan quality, I don't have any beef with the CM fans. I'm still using the one that came with my Centurion 6 years ago. As long as they move some air quietly, that's all they need to do. I do like Scythe Gentle Typhoon fans though, for moving lots of air nearly silently.

I have a few Silverstone 120mm fans that are really loud at their max 2400RPM, but at 1500RPM (controlled with a Sunbeam fan controller, not very expensive) they are less noisy than my power supply.
 
Digitoxin said:
The power supply is fairly new. Is there something specifically wrong with this model that I should know about or do you dislike Ultra models in general?
Click to expand...

Ultra has some decent power supplies, and they have some that are downright awful. The X3 600 isn't their worst product ever, and it's not an "oh my god oh my god get it out of your system RIGHT NOW OH GOD SOMEONE GET A FIRE EXTINGUISHER AAAAGH" issue, but considering an upgrade may be worthwhile. [H] reviewed it, and it managed to avoid bursting into flame, but it didn't manage to do 600w. It might hit 600w in your case since it's being fed room-temperature air, but I wouldn't trust it to do it reliably or while keeping ripple under control. It might-the results at 80% load weren't a train wreck by any means-but I wouldn't trust it. It's not the end of the world because your system probably doesn't pull more than about 300-350w from the wall under 100% load, if even that, but if you want to upgrade something I'd start by replacing this with a better power supply in about the 600w range just to give you room for further upgrades down the road.


The CPU heatsink is also brand new. Because of budget constraints, I get what I can afford. I got the heatsink for $20 and I already had the second fan to attach to it. Yes, I'm using cheap coolermaster fans, just not the ones that came with the case. They were too slow. All of my 120 mm fans are running at 2000 RPM. What is the benefit of higher quality fans? Do they have more fins, are they faster, or do they just last longer before they need to be replaced?
Click to expand...

Fair enough; the TX isn't an awful heatsink, it's just smaller than some others and thus it needs more airflow to perform similarly-and at some point it just won't be able to keep up at all, no matter how much air you push through it. You might get better performance out of it with the higher speed fan set as the "puller" and the lower speed fan pushing, and by making a duct (pieces of an old cereal box) to cover the open sides of the heatsink and force air to flow all the way through it, but you'd have to experiment a bit.

As far as the benefits of higher quality fans... There's a few. Just like a company slapping a 500w sticker on a power supply that's barely capable of 135w while staying in spec, a lot of case fan companies list specifications that often times have little connection to reality.

To put it simply, all 2000rpm 120mm fans won't necessarily move the same amount of air or be equally loud. They should for the most part be relatively similar, but there can still be enough variation that one fan will significantly outperform another.

Airflow, noise and static pressure (i.e. how "hard" the fan can push the air, which is especially important when using a fan on a heatsink or a radiator, but which also affects the performance of case fans) are a function not just of how fast the fan spins, but also the design of the impeller itself. The angle and shape of the blades and the number of blades can all impact how much air a fan moves, how much pressure it can develop and how much noise it makes. And often times, less honest manufacturers will fudge these specifications by making measurements in ways that get them numbers that are favorable for them.

So, a good fan like the Sanyo Denki 9S1212M401 (rated 1850rpm/59cfm/24dB) or 9S1212F401 (rated 2200rpm/71cfm/30dB) may in fact move more air and/or be quieter than a CoolerMaster R4-L2R-20CG-GP, which is rated for 2000rpms, 90cfm and 19dB. There are cheaper case fans that are probably honestly (or at least fairly honestly) rated, but a lot of them-and that particular CoolerMaster fan is a prime example-have stats that are complete BS.

How do you tell when they're complete BS? Because numbers can only be fudged so much before they start looking off. For instance, take the M401 I mentioned earlier; Sanyo Denki's reputation for quality is pretty much beyond reproach, so their numbers are a good reference. That fan is rated at 1850rpms, 59cfm, 24dB. The 1850rpm Scythe Gentle Typhoon is rated for 57cfm, 28dB. They may not generate the same static pressure, but the airflow is nearly the same and noise is very similar.

Similarly, NMB (which is another company whose credibility is pretty damn solid) makes a 1900rpm fan that flows 76cfm at 31dB, which meshes nicely with the 1900rpm Scythe S-Flex that's rated for 75cfm at 35dB. When you see numbers like 19dB AND 90cfm on the same fan, something is probably off.

And yes, higher quality fans last longer. Sanyo Denki rates the M401 at 40,000 hours, which sounds pretty standard. But that's 40,000 hours with a 90% survival rate in a free air condition operating continuously at 60*C ambient temperatures. A $5 120mm fan might have a 40k hour MTBF, but be rated with a 50% survival rate in free air at 25*C.

Anyhow, to get back to your question, the advantage to you is that higher quality fans may drop your temperatures and/or make the system noticeably quieter. If the CM fans are already moving enough air to keep the case at or near ambient temperature inside though, you won't see any gains from more airflow. Is the air coming out of the top/back of the case noticeably warmer than the rest of the room?

As far as covering the side panel vent over the CPU goes... Try it. It'll take all of 30 seconds to fold a piece of paper and tape it over it. It may help, it may not. My guess is that it'll be a trivial difference either way, but there's no reason to not try it. :)
 
Last edited:
Thanks for the feedback. I checked my UPS, and when idling, I am drawing around 280 watts. This incudes my PC and at least 1 of my displays. I can't remember if the other is hooked up to the battery or not. I'll check when I get home to see what is being drawn at full load. I'll definitely have to upgrade PSU's if I go SLI, but I think I'll be fine with this one otherwise. I do not have the budget right now for any major upgrades for a while which is why I'm trying to squeeze every last bit of peformance out of what I have. I recently upgraded to the GTS 250 from a Geforce 7950 and was only able to do that because I got a really good deal on the card and it was by birthday. This setup is all I have for a while. It will probably have to last me at least another year. Having children is the most efficient way to make your disposable income vanish.
 
You must log in or register to reply here.
Back
Top