Hello,

I am wondering what cases are suitable to run a system at least in idle mode at 0rpm? With those new 35 watt I3 CPUs coming, onboard graphics and a fanless PSU it should be easily possible to run fanless in idle right? For stress times or high summer one can always plug in case fans and activate them with a fan controller.

So what cases do you recommend? I think they have to have an intake in the bottom and exhaust at the top, for the convection airflow. But how are the PSU ,mainboard and stuff best arranged? Hot parts at the top, important cooler parts like PSU at the bottom?

Hi and welcome jamotide,

In my opinion it depends witch total tdp you have to cool

for high tdp an open case like antec skeleton / LanBoy is i think the best

for a low tdp: ( cpu: i3 32nm with big heatsink like hr-02 and gpu hd5450 with an accelero) i think you can use a regular case but I maybe wrong, fanless parts from manufacters needs a litle airflow.

For small cases, check logicsupply.com, a SPCR supplier. Let us know if you need to know which cases are best suited for fanless operation but I'll think it's pretty obvious: unless you're going to use the case itself as a heatsink (with a heatpipe), you want many holes and you want them fairly big.

edit: I think what you need more than an intake at the bottom is some room under the heatsinks which should be easy to obtain when the board is positioned vertically. An external brick will limit the amount of heat generated in the case somewhat (as opposed to an integrated power supply).

I don't think there's a universal answer to such a generic question.

Just for example, I run since more than two years an Antec Solo with a slightly overclocked Core 2 Duo totally fanless: a TR HR01 as cpu heatsink (ducted to a not working Slipstream), a Quiet Drive - with a Momentus 7200.4 inside - elastically suspended, a fanless overclocked Nvidia 7600GT, all feed by a FSP Zen 300 (ram is four Dominator sticks): the only noticeable source of noise is the DVD burner when working.

MiniBox M350
http://www.mini-box.com/M350-universal- ... -enclosure

note: only for mini-itx, and only low power processors/chipsets (and my 10W D945GSEJT was running hotter in there than I liked...)

It seems pretty clear that the OP is looking at a classic SPCR low power system. If the 35W TDP CPU is going to be the main heat source in the PC (ie, no discrete GPU), then the whole machine, with SSDs, would probably not exceed 50W DC max. With a picoPSU or similar DC/DC converter + efficient AC/DC brick, this system could run fanless in any number of cases. There are only a couple of things to look for...

1) big CPU heatsink w/ widely spaced fins oriented for good up/down airflow when installed on the mobo/case. Lots of options.
2) case w/ wide open vents -- at least one (usually in front) below the level of the HS and one above (usually in back or on top)

If your components don't have audible electronic whine (which is the bane of any fanless electronic device that pulls more than a couple watts), then a case made from metal mesh would be ideal. Such cases don't really exist -- but some gaming cases are are almost there. Get one with lots of vents everywhere that's the right size for you and remove all the fans -- except one for emergency cooling... or adding wide-band noise in case you need to mask some electronic whining noise.

Yes, the holes/vent above above the heatsink is what matters most in my modest experience. Even if there are no intakes below the level of the heatsink, convection seems to work pretty well if air can freely flow up from the heatsink.

Morex makes small cases that look like are essentially made of metal mesh. Maybe they (or someone else) also make bigger ones.

If you can run that fanless in a normal case like Antec solo which does not even have top exhaust holes, then any case would be suitable.
That is certainly good to hear, I was thinking about seasonic fanless PSU, one of the I3 with 35W with a Scythe Ninja heatsink, some low power ram and when thats running well, I will try adding a Powercolor fanless 6850, with backup case fans somewhere which I will turn off in idle.
Those small mini pcs are not what I can use, due to the enormous size of the fanless 6850.

Did you ever try this system? I'd imagine the 6850 would overheat, or overheat other components.