Project Stoic

CrazyRob

[H]ard|Gawd
Joined
Aug 26, 2004
Messages
1,274
Well, I've decided it's time to upgrade my htpc, and I've also convinced myself that I can build it passive and motionless. No fans. No moving parts. But, it also has to be powerful enough to handle multiple HD video streams simultaneously, as it will be used to play bluray (3d) iso's while recording up to 3 hd channels via my HD Home Run Prime.

Now, I know a computer that can do these things isn't terribly hard to build, but 100% motionless? That's a little more challenging. And, just to make it even more interesting, it's gonna be mini-itx.

I've decided to make this a work log. Even though I'm not planning on doing any case mods or custom coolers, I haven't seen too many performance passive pc's online so I figured I'd share in case others want to do something similar.

This is not a priority project for me, so it'll likely be shaping together over the next few weeks, of course assuming I don't run into any major issues. But, enough introduction.

Project Stoic:

Planned configuration.

AMD A10-5800k APU
Asrock FM2A75M-ITX motherboard
Phanteks PH-TC14PE_BK Heatsink without fans
Crucial Ballistix Sport 8GB DDR3 1600 Low Profile Desktop Memory
Corsair F120 SSD
SeaSonic X series SS-400FL PSU
Bitfenix Prodigy Black case

I've already identified several hurdles to overcome:

1) Will this configuration actually run cool enough to run passively?
2) Can I modify a backplate to mount the cooler to this board? *done*
3) Will the cooler on this board actually fit in this case?
4) And, possibly the biggest hurdle, can I get my hands on a revision of this board that won't catch on fire? *done*

I already have the case and ssd, with the motherboard and apu on it's way. More to come soon!
 
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CrazyRob

[H]ard|Gawd
Joined
Aug 26, 2004
Messages
1,274
Update #1: The case.

As you can see, I've removed all the stock fans, hard drive cages, optical drive bay, and psu fan filter. I chose the black version of this case in particular because it is the only version with a ventilated face. If the heatsink allows it, I will likely reinstall the optical drive bay and add a blu ray drive, in case I ever decide to play a movie directly from disc instead of a mounted image.

Update#2 The motherboard/cpu.

Woohoo, it didn't immediately catch on fire! I did a quick build on my test bench with a temporary cooler/psu/ram, and everythings working like a charm. I disabled turbo mode and enabled cool and quiet, and did some inital testing with blu ray 3d. So far, load stays under 10%, which means recording hd streams on the side shouldn't be a problem. Also, the temps were mid 40's with the stock cooler, and I haven't even undervolted it yet. Tomorrow I will be further stress testing the board as well as seeing how low of a cpu voltage I can go under 100% load.

Update #3 CPU Voltages.
I've been trying to find the lowest stable voltage for the cpu under full load, even though that will likely never happen in application. So far I've been stressing with Prime95, and I think I've settled on 1.2875v. At 1.275 one of the cores failed after 10 mins. So far it's been stable for a few hours, with the cpu temp peaking around 52c. Going to continue stress testing at this configuration tomorrow, and will likely start tackling cpu backplate mounting/modification on Monday. *edit* after a couple hours, one of the cores crashed again, so gave it another small voltage bump.

Update #4 Couldn't wait.
Well, last night, I pulled the trigger and ordered the memory. Today I ran prime95 for 4 hours without an issue, so I think I may have settled on the voltage.

I decided to tackle the cpu backplate issue, since the phanteks cooler uses a stock am3 style backplate, but, although using the same holes, fm2 uses a little plastic clips. On the back of the board, though, Asrock mounted components that would directly interfere with a backplate. I first considered dremeling out sections of the plate to fit, but after seeing how much would have to be cut out, I decided to just pad it with foam instead. To remount the same cooler, I also had to attach the bracket, which also interfered with board components, so I clipped part of it away. The end result was still more solid of a mount compared to the stock clips, despite my modifications.

*Long Overdue Update*
Well, the heatsink fit without too many problems. I didn't realize with this particular design of heatsink and cpu socket, it can only be mounted in one orientation. I had originally planned to mount it so that if a fan was installed, it would be blowing out the back, but that's just not an option with this motherboard. If I had gone with a z77 platform, rotation would have been an option, but the am3 hole patterns are not square, so it only mounts the one way. Additionally, the standard 140mm fan was too thick to fit between the heatsink and the back of the case, so that's not an option either (although a thinner fan may work).

On the other hand, memory clearance in this configuration was great! I tested with a few other modules, and it turns out a standard size memory module would have worked fine. The taller Ripjaws module was touching the heatsink, but it did fit. I personally wouldn't run it like that, but it is doable in a pinch, and if you must, you could run a single very tall module in the outside slot.

As I've mentioned below, without fans, the computer just doesn't quite dissipate heat fast enough during bluray playback. A single, low-rpm fan was more than sufficient for keeping temps down. I'm still looking into fan control options but I've run into some quirks with the board and how it monitors/controls fan rpm. Instead of selecting whether you have a 3 pin or pwm fan in the bios, they physically attached separate pwm and 3 pin fan headers for the cpu fan.

The (stock) fan I'm using is 3 pin. Plugging it into the 4 pin header runs the fan at full speed all the time. Adjusting the fan speed in the bios doesn't make any difference. Plugging it into the 3 pin header does allow me to control the fan speed, but the port is not monitored, so I can't see what speed the fan is running at in the bios or with 3rd party apps like speedfan. To combat this, I have hacked together a fan adapter that will draw power from the 3pin but report rpm to the 4 pin, so that I can monitor and see the changes that I'm making. After I get that working, I'm going to look into software options to see if I can get the fan to turn off at idle, but turn on when over a certain temperature.

But for now, it's been working great, and as it is, is pretty darn quiet. Eventually I'll get around to fiddling with it more, but it's been working so well, I haven't had the urge to pull it apart again.
 
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CrazyRob

[H]ard|Gawd
Joined
Aug 26, 2004
Messages
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hoping to order the heatsink and power supply after the first of the month, so hopefully i'll get this thing done by the end of next week! I've been using it as is in it's intended role, and it's been working great. I was a little concerned about heat trapped by my padded backplate, but it seems to not be an issue.

*edit* heatsink and psu ordered. Can't wait...
 
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CrazyRob

[H]ard|Gawd
Joined
Aug 26, 2004
Messages
1,274
Wow, this week ended up more busy than I anticipated. Not only did I get the parts over the weekend, but I got to upgrade/configure/test a system with 3 Titans at work.

I will post more pictures and details I took during my psu/cooler upgrade, but I'll get straight to the end. It looks like I will not be able to run that a10-5800k 24/7 passive. For dvd playback it was no problem, but playing blu ray I watched the temp creep up to and pass AMD's max recommended temp of 74c. Funny thing is, having a single 140mm fan on it at lowest speed setting in the bios with an additional in line resistor keeps the temp under 40c. I'm gonna see if I can't rig a custom profile to keep the fan off and then only turn it on briefly when it warms up.

There were all sorts of other hurdles I ran into along the way, so I definitely will update my log, but just a little too busy atm :( I guess I'll just have to suffer through playing around with these Titans ;)
 
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