miniITX FM2 HTPC Build **2nd system added!**

[Ryhadar]

Looking great!

Here are my two cents: I'm going to second ludi's comments. The fan may be moving a lot of air but that fan's rotor is huge (looks to be 60mm in diameter by a very rough estimate) and is likely robbing the heatsink of the airflow it desperately needs.

Just looking how huge the heatsink is compared to your case makes me think it's not a good fit. I think it might be time to try one of these instead: http://www.noctua.at/main.php?show=prod ... =51&lng=en

Looks like NCIX has one for sale for fairly cheap: http://us.ncix.com/products/?sku=77371

This little guy stands 37mm tall with the fan so you'll have more than enough room for both the 180mm AP-181 and the fan that comes with the it. Additionally, AMD CPUs always seem to give their processors a little too much voltage by default. If you're not OCing, I betcha you can shave off at least a tenth of a watt which will help you in the cooling department. Speaking of, the cooling is actually pretty good based on this one review (French): http://www.lesconfigs.com/reviews/noctua-nh-l9i/5/

Looking forward to seeing the final project.

[yogibbear]

This thing looks AWESOME!

I want to make one...

Though to get enough decent airflow I think you might end up having to make a funnel type arrangement in a X x X sided box shape between the fan and the unit... with sort of a cone pointing in at the heatsink.

[drfish]

This little guy stands 37mm tall with the fan so you'll have more than enough room for both the 180mm AP-181 and the fan that comes with the it. Additionally, AMD CPUs always seem to give their processors a little too much voltage by default. If you're not OCing, I betcha you can shave off at least a tenth of a watt which will help you in the cooling department. Speaking of, the cooling is actually pretty good based on this one review (French): http://www.lesconfigs.com/reviews/noctua-nh-l9i/5/

37mm w/ the fan? Pfft... Too easy. I wouldn't even need my ostentatious 180mm fan on the side. This is very much a, "because I can" build (or, "because I think I can rather") It might not be be full of the smartest choices but that's not the point, its more of an intentional form followed by function thing - but hopefully the function bit works out ok too. I do plan on trying to undervolt it regardless...

Though to get enough decent airflow I think you might end up having to make a funnel type arrangement in a X x X sided box shape between the fan and the unit... with sort of a cone pointing in at the heatsink.

I'm going to try some stuff to get some room between the fan and the heatsink (there is none right now) but the spacer I ordered only gives me 7mm to work with so I'm not expecting to have room for much of a funnel and I don't want to build it out much further than that. We'll see if some breathing room offers any help at all after I mess with it over the weekend...

Thanks all for your feedback so far.

[Ryhadar]

37mm w/ the fan? Pfft... Too easy. I wouldn't even need my ostentatious 180mm fan on the side. This is very much a, "because I can" build (or, "because I think I can rather") It might not be be full of the smartest choices but that's not the point, its more of an intentional form followed by function thing - but hopefully the function bit works out ok too. I do plan on trying to undervolt it regardless...

Well... I certainly understand that logic myself.

How much room, would you say, you have between the heatsink and the 180mm fan?

Also, if you wanted to take it to 11, I've seen people take a sander and sand the top of the heatsink down until they have enough room. You might reduce your cooling a bit, but if it's enough to add another fan, say a 12mm think scythe 120mm then I say go for it.

[DPete27]

Just for others, that AsRock FM2 mITX board popped up on newegg Wednesday.

Can you post a pic with the fan filter off looking through the big fan into the heatsink so we can see how much it's covering up?

[drfish]

How much room, would you say, you have between the heatsink and the 180mm fan?

Precisely 0mm.

Can you post a pic with the fan filter off looking through the big fan into the heatsink so we can see how much it's covering up?

That's a good idea, I will do that. I bet its not pretty...

[DPete27]

Also, for my own personal benefit (since I'm planning almost the exact same build, minus the case) how much room is between your RAM and the CM Gemin heatsink? I have some G-Skill Sniper series dimms I'd like to use if they'll fit underneath.

[JustAnEngineer]

You could install a spacer/gasket (like this but sized for your fan) between the large fan and the side of the case. This standoff would give you a bit of room to allow some airflow to get to the middle of your heatsink.

[drfish]

That's exactly what I ordered. However based on some initial testing it will probably help, but not enough... Pics and data to follow...

[drfish]

Ok, first things first, the clearance between the heatsink and the RAM is 11mm - so miles of room compared to some of the space I'm working with here.

Second, here is the shot of the fan with the grille off showing the heatsink below. Its bad but in my head I had made it worse.




This is what things look like with the stock fan installed and below is a chart of a 1 hour OCCT run.





Same thing with the modded side but with it lifted, note the higher temps. If I run this test without the spacers and without clipping the side on it shuts down toward the very end of an hour. If I clip the side on all the way it boots into Windows and shuts down at 60C very quickly... It seems something around 1/2" is what I need to make this work decently - the single 7mm spacer I ordered is not likely to cut it...

[ludi]

Suggest shrouding all of the area around the heatsink perimeter so that the fan is forced to push all its air through the sink (a piece of tagboard should be fine for a test run). Right now I'll bet if you smoke-tested the fan you would see nearly all of the air moving around the sink, and the majority of it probably still would with the spacer installed, because in fluid-flow terms, the heatsink is basically a rock in the stream.

EDIT: To clarify, here is why I think this layout won't do the trick without a shroud:



The GREEN line is the area occupied by the heatsink. The BLUE line shows the area around the hub where there will be effectively no airflow. And the RED lines, unless I'm seriously mistaken, delineate the approximate area where the fan will generate maximum pressure. Right now, most of the fan's "butter zone" is venting into open case, and the heatsink is basically both sitting in, and helping to create, a giant dead zone.

[MadManOriginal]

Now I wonder if the case side is affecting the heatsink-heatspreader contact (yes, I still think it's that, or at least it plays an important role ) Maybe it's not just '0mm' but is actually <0mm and alters the heatsink contact. The reason I think the contact is an issue is because the temperature behavior seems extreme just for low airflow. It's one thing to overheat under serious load, but just in BIOS or booting Windows is another thing.

[JustAnEngineer]

It's pretty clear that you're better off with the 120mm fan matched to this CPU cooler. Would something like the Scythe Big Shuriken 2B be short enough to allow more air flow?

[drfish]

The Big Shuriken 2 is clearly the superior cooler and I would have liked to use it instead, however without their fans the Coolmaster is 4mm shorter and that is currently what allows this to work at all.

MadManOriginal, I've wondered about that too, its certainly possible.

Thanks for the graphic ludi! I've been thinking about this since last night and this morning it dawned on me that a small (7") paper plate would be the perfect prototype shroud, it has nearly the perfect profile already (7mm height is my bogey) and it already has sides that curve in on the edges - its also super easy to modify. I'm wondering if a paper plate with a heatsink shaped hole cut out of the middle (well, offset just a little) would work. I'll try both ways...

[Thatguy]

Have you tried facing the fan to pull the hot air out? I have no idea if it would help much but it's certainly easy to try.

[drfish]

Until I can install a spacer I don't trust the fan not to hit things inside the case if I flipped it - also it should be easier to filter the air going into the fan instead of in the sides of the case.

This is the test I ran this morning, just to see if it was the right direction...



...and the results, success! At least we're going in the right direction. FYI I think the CPU usage spikes have something to do with this test being run in Win8 while the first two were run in Win7 - the CPU frequency chart looks the same across both.


Next step is to build a respectable shroud with some 20mil HDPE and the 7mm spacer I have coming in the the mail... Hopefully I can get similar results with half the spacing...

[DPete27]

I'm confused here, so your temps are 45C with the stock fan and only 48C with the big fan + 7mm spacers? 48C isn't that high considering your CPU usage is 100%. I wouldn't worry about a 3C increase over the stock fan. MadMan has a good point that without the spacers, you may be so tight that you're pushing on the heatsink and losing contact with the CPU.

Nice keyboard by the way. I have the same one, it's great for HTPC.

[drfish]

Stock fan -> 45C (can't close case)
Big fan no spacers -> 60C+ FAIL
Big fan with 1/2" spacers -> 48C (can't close case)
Big fan with plate mod (slightly less than 1/2" spacing) -> 44C (can't close case)
Big fan with 7mm spacer and final shroud design -> unknown until next week, will be able to close case

[DPete27]

I would just use the 7mm spacer and no shroud. I could live with 48C under 100% load.

[drfish]

I forgot to include one of my tests on that list, the no spacer but side not completely clipped on test - which is probably the best approximation of the 7mm spacer - it didn't end well. I think it will need additional help.

[drfish]

...and its finished! But does it work as intended?

This is the spacer temporarily pinned in place to show off the shroud I made out of the 20mil HDPE. It overlaps the heatsink a little bit all the way around so it is supported and won't let air get around it under pressure.


Shroud and spacer mounted to the side and fan - just go ahead and ignore the homemade plastic washers on the top and bottom of the right side...


Same shot as shared previously but this time showing how all the guts are hidden by the shroud.


"The stack" -> side, shroud, spacer, fan, and grille.


*drum roll*

Success! With the fan on high (as it was for previous test) this setup records the lowest results the system has achieved so far. The success may be slightly overstated because the ambient temp in the basement last night was cooler than when I tested previously - but not my much...


Now this is the really important one - the fan on low is significantly quieter than on high and my intention has always been to have it running on low - and it seems I will be able to! I need to run a longer duration test though - as you can see the temp was slowly climbing even after the hour was nearly over. I also need to run a test with both the CPU and GPU stressed at the same time (with my Kill-A-Watt inline) - but at least I know I'm beating the stock fan with my modded setup.


Where could I go from here? How about using a hairnet as a disposable dust filter for the intake? Maybe its too early in the morning but I don't think that's crazy, do you?

[Messy Snot]

I created an account just to say thanks for sharing your project with us! I think it's awesome.

[drfish]

Thanks for taking the time, I'm glad you've enjoyed reading about it, it was fun to share too.

Now I really need to stress test it, get the final power draw numbers too... Since its going to be the HTPC it basically needs to be the most stable system in the house - my old one has been a champ so I don't take replacing it lightly - I don't want any surprises...

[MadManOriginal]

Does anyone know the specs on the Antec DC-DC power board? All I could find was specs for the AC-DC adaptor, which doesn't tell anything about the power capabilities of the output rails for the DC-DC board.

[Walkintarget]

Nice keyboard by the way. I have the same one, it's great for HTPC.

Agreed ! I just bought one a few months back to replace my original Microsoft Media Center keyboard. As soon as I saw the USB dongle on the front of the case, I thought, oh cool, a Logitech K400 must be nearby !! I got mine for $17 from Staples, an outrageously low price for such a fine HTPC keyboard.

[drfish]

Yep, I'm a fan.

[drfish]

Ok, got my Kill-A-Watt inline... And some weirdness to report...

At idle the system draws 20 watts. Color me impressed.

Under full CPU load the system draws 100-120 watts... Huh? It shouldn't be doing that...

Under Furmark GPU load it dies instantly, just shuts right off... That's not good... Lesser graphical loads seem to be just fine - and the temp doesn't look like the reason the GPU would kill it - not even stressing the CPU at the same time...

[Ryhadar]

Sounds like the 90W adapter is running out of juice with the GPU load.

Can you purchase a better external power supply? I'm not familiar with the internal PSU of your case but even though antec gave you a 90W external power supply the internal electrical components may be rated for something higher. Antec may have that information on their site, or it could be written on the PCB of the internal PSU components.

If all else fails, there's is always the picoPSU.

Oh, and it sounds like it's time to undervolt.

[MadManOriginal]

The idle load is not surprising, you've got a low wattage PSU and with a 650W PSU TR gets 24W idle. The load numbers are maybe curious, but it's why I have wanted to see load tests of the A10-5700 - it's not terribly downclocked from the A10-5800K, mainly in base clock not Turbo clock - so I wondered if it's actual power consumption was 'really' 35W less as the TDP suggests. (TDP != power draw even though lots of people treat it that way.) Furmark may just load up the CPU enough that combined with the 'power virus' GPU load it's too much for the PSU.

It's also why I asked about the output rails of the DC-DC part of the Antec PSU. I have looked at brick+DC-DC PSUs in detail before and the overall wattage ratings can be misleading. The 160W Pico PSU for example is only rated for 8A continuous (12A peak for max of 60 seconds) on the 12V rail - that is only 96W continuous (144W for 60 seconds). Modern PCs put most of their load on the 12V rail so it's a detail that's important.

[drfish]

I was basing my load expectations on the Anandtech review of two systems built into the same case. The got 56w under load for a 65w triple core Llano chip... I wasn't expecting anything quite that low but still...

Will keep researching and testing. Thanks for the input.

Edit: Found this on Hexus. 76w under 3D gaming load - I'm sure my system could do that... But is that really good enough? Hmm...