or out ?

Hi.

I've bought that wonderfully small MB, and the passive M350 case. I'm using it VESA-mounted at the back of my monitor, with the MB's cooling fins vertical for better airflow. The beast is still at 60°C, including the HDD that's very close to it. Cooling fans are in order... and luckily, the M-350 supports a pair of 4cm fans via an optional support bar. I've got a pair of very low RPM, silent ones.

Questions:

1- Should I have these fans blow in (which I think will be more efficient at getting air to flow through the cooling fins) or out, to get more heat out of the case ?

2- Do you think my Samsung M7E 2-platter 5400 RPM HD contributes a lot to the heat and that replacing it with an SSD would negate the need for active cooling ?

Thanks for your advice.

Thank you for your report.
It would be helpful if you could state exactly how you got that 60C and what are temperatures like if the case is laid horizontally.

Your drive only makes a significant contribution inasmuch as it blocks airflow. An SSD would also block airflow.
60C at load is probably OK but may be too high for the hard drive. I don't know what temperatures SSDs are supposed to handle.

A single fans should be sufficient. I'd blow in at the bottom or out at the top to leverage convection but I don't know if that makes a difference. It might not even be optimal. Maybe blowing from the side against the bulk of the heatsink would be best.

double post, sorry, see below.

Thanks for your reply.

Laying the case horizontally does not seem to have much of an impact on temperature.

I don't have much choice as to where to locate the fans: there's only room for them over the "left" side of the heatsink on the photo, ie over the part that starts at the ASUS written on the heatsink, and ends at the side of the heatsink that is aligned with the 2 wifi antennas and the PS2 port you can see on the back panel (you may have to squint ^^). The two fans are positionned side by side, so they cover the whole depth of the heatsink, from back panel to the empty space to the left of the big blue P4 power connector. That seems a good spot for them to be, directly above the APU (newspeak for CPU+GPU+chipset).

I guess I'll try blowing the air out, it seems to make more sense. I seem to remember reading that it was better to blow in for cramped cases, though.

I'm still wondering about the hard disk. I have another one (different brand/model, but still 2-platter 5400) in a cheap aluminum external enclosure, and it does get quite hot (my guess would be 50ish, °C) when in intensive use. So on top of cutting airflow, which indeed an SSD would also do, I'm wondering if the HDD may also be contributing a non-negligible amount of heat on its own, which an SSD probably wouldn't ?

PS Actually, found a picture of the open case, with the 2 identical rails, that both accept either an HDD or a couple of 4cm fans. Of course the case picture is facing front, while the motherboard's picture is facing back. So in my case, I've actually reversed the HDD compared to the picture. That way I have room for my prospective fans over the APU, and the HD is at the bottom of my vertical case, getting fresh air instead of hot.

Darn, brain overheating too !

The M350 also has room for a 40mm fan behind the front bezel. I have two systems in these cases and I found that this fan alone - even if it is a low-noise, low airflow fan - can dramatically affect overall case temperature. Assuming your VESA mount has the front Bezel facing "up", I'd put the fans on the bracket blowing in and mount a third one blowing out behind the bezel.

One of the biggest problems with this case is that it has too many holes...lots of available air but it just goes in and out the little holes indiscriminately. For really low-power (atom/ARM) designs it works OK, but as power/heat goes up you need to establish some pattern of airflow. Not exactly sure how to fix that.

Thanks a lot for the tip. My cases came w/o manuals, and I hadn't seen that 3rd fan mount.

Gonna try it as soon as I feel up to disconnecting for a few minutes !

This board shouldn't consume much more power (if any) than a desktop Atom.


I've been very wrong about airflow before but blowing out may draw air from other places than the heatsink (with so many holes) unless you blow out from above (in that case convection helps you).

Fair points. I've found that with no fans this case experiences lots of heat buildup. My two Atom systems - A D510 and an older 330 - both run very, very hot in the M350 with no fans. But just adding a small amount of exhaust from the fan mount behind the bezel drops it down to nearly the same temps you'd get in open air. And this is using a very quiet fan that moves an almost undetectable volume of air (Scythe Mini-Kaze). All you've got to do is create the smallest bit of negative pressure and all those holes start working wonders...

My point above was simply that you could likely do lots better if the airflow were more controlled. Might be a simple as blocking some/all of the holes nearest the exhaust fan so that the air is forced to travel through the case. Convection would help too - no matter how you mount it, make sure that the exhaust fan is located near the "top".

I've put 2 fans, one behind the bezel on the right, the other one at the back right-side mount, both blowing air out, and the case vertical, right side up (so the cables don't fall off, and the cooling fins are vertical, and both fans towards the top (though neither are on the top side, both are at the top of lateral sides, if that sentence makes any sense).

The result is dramatic: from 60-65 °C to 45-50, so -10°C, which google tells me is 36°F (from 149°F to 113°F), and really means going from the "uncomfortably and disquietingly hot" to "nothing to see, move along". The noise is minimal and non-intrusive, and the top of the case, which used to be uncomfortably hot to touch, is now cool, not even warm-ish. The motherboard itself is even cooler than the CPU. I'm having doubts about what my HD is reporting to Speedfan's SMART module, as it reports no change (still 150°F-ish).

Asus Probe reports the fans are going at 4,000-5,000 RPM though, and that's on the "silent" BIOS setting.

Could you post the smartmontools reading? Speedfan may be mistaken.


Do you have numbers and details (board, orientation, ambient temperature) for the D510? I've posted temperatures with a couple of D510 models in a couple of cases and it would be interesting to compare.
I'm running D510s fanless and temperatures are of course very sensitive to the case and positioning. We'll see if I get a high failure rate before these cheap boards are made obsolete...

HDD is not in the database though. I'm not sure what value is relevant: raw ? value ? why is "worst" lower than "value" ?

I'll get some temps tonight. The D510 is currently sitting flat on a countertop, quietly doings its thing (which is mostly limited to being being a print server right now...). I haven't really touched it in over a year. The 330 is running at exactly ambient...which I know without measuring because it is not powered up

It looks like your drive's temperature is 35C, which is totally safe.

If your Zacate board is supposed to run safely at 60C and that was the temperature at load, I wouldn't use a fan. Then again your board is quite a bit pricier than a D510 so you might want to err on the safe side...

I can't help but feel Asus should have shaved 5mm off of the heatsink, and put a large (12cm ?), thin (1cm might not even require any shaving), slow fan pretty much covering the whole thing. Or at least, given us the option to do it by adding screw holes in the right places.

The system is sitting flat, on a countertop in a corner with poor ventilation.
Apparently my exhaust fan has failed...it is not spinning. Hadn't looked at it in quite some time.

CPU per Coretemp is sitting at 60c, with a recorded high of 62c. Hard disk is sitting at 37c. Kinda hot, but will within spec (Intel says the D510 is good up to 100c Tj - hard to believe, but that is their spec).

I've got another mini-kaze lying around. When I get around to it I'll put it in and get temps again.

Are you talking about a D510MO? Is your 60C idle CPU temperature? In that case, unless your ambient temperature is high, it sounds like the M350 is a poor case for fanless operation. On the other hand, I'd say 60C at load is highish but OK.

The CPU temperature isn't the one to watch with a stock D510MO anyway. Intel only put a heatsink on the CPU and the board can get really hot. They have a sensor on or near the VRM area which they say should stay under 80C if memory serves. You should watch that sensor if you have cooling issues.
There are loads of CPUs rated around 100C. So I believe them. But you don't want the D510MO's CPU anywhere near 100C anyway.
Asus's D510 board has a larger heatsink which seems to keep the board cooler relative to the CPU.

What fully passive, vesa-mountable, pint-size case is good then ? My guess is none, and the better I can hope for is one with good air flow, and a single low-rpm fan ?

I'm having a problem connecting the front panel USB ports, because the picoPSU is quite high, and blocks the front panel USB connector.

Do you guys know of any source for an internal USB cable (female-female) with one head about half as long as usual ? The one I currently have is like the picture below (except all female). The black plastic bit at the end is about twice too long.

I can recommend the Morex T-3500. It's larger than the M350, with room for a slim optical drive, but you still won't be able to see it if it's mounted behind a monitor.
SPCR took pictures of one:
http://www.silentpcreview.com/article1010-page2.html
I built one just like that and put it behind a monitor.

The HDD mounts under the motherboard, behind the optical drive. You can see the screws for it in the third picture. So, it doesn't get in the way of cooling the motherboard.
I don't own an E35M1-I, and the machine I built doesn't need a fan, but I would guess that there would be enough room above it to fit one of the 120 x 120 x 12 mm Scythe fans.

I checked my favorite parts store for a cable, and found this:
http://www.sparkfun.com/products/8535
The plug is rotated 90 degrees from the ribbon, which might give you more room?
I'm not sure if it's pin compatible with USB, it's just a ribbon cable with (I think) the same spacing.

Edit: Sorry. Can USB even run over a ribbon? I have no idea. Maybe you could find a right angle adapter though.