I've got question! (Air Cooling)

[caddi daddi]

look at the coolermaster lanbox, it's small, good quality, holds a 2 fan all in one water cooler, mounts a big azz fan in the top for exaust, you really have to watch the psu size as the space for it is tight and you can run some pretty beefy gpus in it to.
a haf-x is sweet, but it's BIG, as in GREAT BIG.
I like big,, slow, quiet fans if I can't fit 200-230 mm exaust fans in it, I don't want it.
my fave fan, 3 speed antec big boy and the nzxt 230 mm is second.

 

[knoober]

You're not going to get it any quieter without sacrificing airflow, which will hurt temps even more.

Even if I could swap out the rear panel fan for a 120mm and the 92mm on the ceiling for something a little nicer? I guess I never thought of this before, but that little 80mm on the sidewall is always running at pretty high RPM and is damn near silent while it does its work.

What if I moved the 80mm under the HDD cage and stuck a quality 92mm in its place, while replacing the rear with a 120mm and the ceiling fan with another quality 92mm? This is pretty much what Ive decided to do with this build anyway, Im just curious as to your opinions Im also thinking of adding a small fan to the GPU because all it has is passive cooling and I do have a spare header near there in the mobo (but none on the card which is curious because all the pics I see of this card have a fan right on them)

Also the case the guy in the next post suggested IMO is pretty cool and might even be the right size to work in my setup (Id have to take some carefull measurements because the space is set for the width of a tower, but of the height wasnt to high.....) anyway I like that case

Thanks again for all your help guys.

 

[ATMINSIDE]

The fact of the matter is that your current case wasn't built with (any) airflow in mind. You're going to have to do a lot of cutting to get fans worth buying in there.

 

[knoober]

Great minds think alike good sir! I had recently considered that very same thing! There are two things standing in my way:
1) lack of knowledge on where to make the holes. I had considered making the side panel into an almost Swiss cheese like appearance, but I dust and dander are a worry. The bottom is already Swiss cheese straight from the manufacturer, the rear panel is also covered in holes, and I don't want to mess with the bezel, except there is the possibility of opening up the floppy drive slot as a vent.
I know these aren't perfect solutions and it probably would be better just to get a new case, but what are your thoughts in these directions?
2) my tendency as an artist is to not stop before ruining the masterpiece.... I run a serious risk of messing things up just through my own nature have you got any airflow guides I could check out so I can place things properly? I had considered making a case from Legos so that the vents would be wherever the needed to be, but that is an idea for a different day

 

[ATMINSIDE]

Well, the typical convention of airflow is for intake from front/bottom/side and exhaust from top/rear.

 

[knoober]

Well barring some drastically new info I think I have decided what to do. I am going to replace the 92mm on the rear of the case with a 120mm, move the 80mm to the front of the case for increased intake and replace it with a 92mm. Ceiling fan will remain a 92mm, but I am going to search for the quietest I can find. Also the side fan will probably have to be a new quieter running fan as well. Even though I likely won't find something suitable in that size, the the goal anyway.
Is there a formula to determine heat generation so I can plan how much air I will have to move? Or is it just kind of a "by feel" process?

 

[ATMINSIDE]

For your system, I'd guess you need about 60 CFM of airflow through the case.

 

[knoober]

Okay then a couple of final questions and I swear Ill leave this issue be Thanks for all the info. I did finally read the sticky (I know ppl that ask first and read second suck, sorry) and based on the sticky I was hoping to have a couple things clarified.

So , I now have a better understanding of CFM and its relation to static pressure which is a good thing. What Id like to know now is how CFM applies to the case. Lets use a fictional case that is 1 cubic foot (sorry I dont do superscript on a keyboard yet ) This fictional case will then hold an amount of air equal to the space inside correct? SO for the sake of simplicity we'll say this is also exactly 1 cubic foot. Said fictional case has exactly the right size vents (whatever that size is supposed to be) and no impediment to airflow. The case also has 1 case fan that can push/pull 80cfm and good static pressure. This means to me that the volume of air inside the case will be completely replaced 80x every minute . Is this correct or have I misunderstood how such things work?

Also I would like to add another fan to that fictional case , this one pushing in 80cfm, while the other removes 80cfm . Do this setup then push 160 cubic feet of air through the case every minute?

Thanks again for all your help.

 

[ATMINSIDE]

Nope, you have a great handle on how the stuff works now

Adding airflow can work one of two ways. If you're pushing in with both fans, it'll add up to 160CFM.
If one is pushing in and one is pulling out, it'll still be 80CFM. BUT it'll be easier for the fans to move that 80CFM, making it require less static pressure per fan.

 

[knoober]

Well then let's do another quick round of questions & answers.
If bother were pushing in (still in my fictional box) and the cfm were to double, then exhaust with no fan would be_____? I suppose there is some sort of thermal or diffusion principal that would govern a passive exhaust situation?
And the big whammy of all questions : (still in my fictional box here) add a cpu. I don't know how to make a fictional cpu anymore than a real one, so I don't know how to set up the example here, but basically how fast does heat transfer to the air and if there are 80cfm running through the case then what does that mean in terms of cooling. If it is a really complicated answer, feel free to just smile and nod I'm just trying to figure where the point of diminishing returns is. You know, the point where the extra effort doesn't translate into enough performance increase to matter.

 

[ATMINSIDE]

Well, if you're using passive exhaust, it simply takes more static pressure from the intake fans to maintain full airflow.

I can answer your CPU question, but it'll get into my knowledge of Heat Transfer and Thermodynamics from school.
I'm not sure if you want to hear all that, but here's a simplified version.

Know that the rate heat transfers to air is based on the heatsink.
The heatsink will be more efficient the higher the difference between it and the air flowing past it, but we obviously want it as cool as possible.
So, the heatsink's efficiency varies based on CPU wattage and temperature. Obviously we care about full load temperatures, though.
Your CPU is only a 95W chip, which isn't particularly difficult to cool. Although a better heatsink could go a long way for you.
All you can do, though, is keep the air in the case cool so that any heatsink you choose has the best chance to do its job.
Basically, you only need to put enough air through the case to dissipate the heat that's put into the case by your system.
A steady flow of air is plenty, on a system with lower power draw like yours. You don't need a wind tunnel by any means, just proper flow.
If you had a CPU putting out 200W and a GPU putting out 250W you'd need a lot more airflow, but you don't have that.

 

[knoober]

Thanks for the info and the brevity of the explanation. I sensed that could get into some high level knowledge so I tried to ask tentatively. Its not that I wont listen (well okay so most of the time I wont listen but I know that those explanations can be as hard to give as they are to read, especially when they could fall on deaf ears. You did supply the info I was looking for.


And if I reach for a high OC with this chip will it exceed its TDP? I mean Im already exceeding the rating set by the manufacturer (which I know to contain headroom) Seriously though thanks for all the help

 

[ATMINSIDE]

Yeah, without getting into some actual engineering theories and equations, it gets difficult to explain.
And getting into that level gets hard to explain, especially if someone doesn't have that kind of background.

Yes, you can exceed TDP.
What are you running at? Speed and voltage.

 

[knoober]

Ive got 3.0+ a few random mhz by raising the FSB. I had to lower the vcore to 1.31 because the auto setting was just too much in terms of heat. I was burning up on stock settings basically. Undervolting brought the temps back into check and now I'm going to see if I can push for a little more. With a different board I had it up to 3.2 but I couldn't get it stable under load. Which is why I started looking into cooling. I don't want.to do anything heroic like water cooling or pushing for 4Ghz or anything . I just want the best out of what I have , (stability being prized ) and I think I might have it already. But if I can squeeze a bit more safely, I will

 

[ATMINSIDE]

Safety is dependent upon keeping your temperatures in check. Sounds like you're fighting it already because of your cooler, so you likely won't get much more.

 

[knoober]

just a quick update for you guys cuz I figure with all the help you gave you should atleast know the results.

3.0ghz stable. I havent dont a longterm stability test yet, but its made it through an hour. Temps are still on the high side (got a 68C) but Im working on getting a different set of fans and maybe a new cooler... or maybe modding the cooler Ive got, which sounmds like alot more fun. I think some copper stirps fixed to the fins of the heatsink with thermal paste is something I might try. FIrst Ill lower it back to stock and be prepared to replace the cooler I may ruid though Thanks again

 

[ATMINSIDE]

Yeah, back that down... Too hot for a Phenom chip.

 

[dyckah]

He's got tinsnips, a drill, and a willingness to mod.
Could he not just drill new fan mounts where his existing ones are, except for a 120/140mm fan? And then cut the hole larger to match it? That should help with airflow and decrease noise at the same time, no?

Edit.
Wow, missed the whole second page, but bigger fans should help move that air away better. 80 and 92mm fans are just too noisy!

 

[ATMINSIDE]

He's got tinsnips, a drill, and a willingness to mod.
Could he not just drill new fan mounts where his existing ones are, except for a 120/140mm fan? And then cut the hole larger to match it? That should help with airflow and decrease noise at the same time, no?

Most spots in that case aren't wide enough to accommodate a 120mm fan, from what I can see.

 

[knoober]

Back to update a bit: Still havent gotten any new fans, but thats a budget concern, and Ill get em when I can. Manufacturer specs say itll take 120mm on the rear wall and from underneath, so I think Ill fall back on what I said before. 120mm on the rear, cut a bigger hold for a 120mm on the side (in place of the 80mm thats already there) and the quietest 92 I can find for the ceiling (ceiling wont support anything bigger than a 92mm, but Im hoping that in conjunction with the others I can have it run A a low enough RPM to be quiet....er) Im still keeping my options open for front mounted fans. I can easily rearrange things around the HDD cage to fit an 80mm (maybe needs to be smaller) fan to intake there, and if more is needed , like I said, the floppy sliot can be removed and a fan set there for intake as well. I even came up with a great DIY for fan grills (ill post about it if it works good enough)

Ive also got another PSU on the way, Im taking all kinds of flack about it from every direction on multiple forums Apparently its known to be the most heinous beast of the bunch. The longer I run it the less confidence I have in it as well. So many small failures could be attributed to it that a replacement is warranted. The real question is what to do with the old one. Anyone got any real cool hacks for a cheap PSU? Maybe modding it to run a flea circus or something? Anyhow I didnt get a notification that there were furthur posts or I would have kept up better.