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Silent M-ITX box with AMD Kaveri 7850K

Posted: Mon Feb 10, 2014 1:18 pm
by N-K
I wanted to "update" my current computer to be just a bit smaller. The old box had i3 2100 with GTX 660.
The CPU was alright and fast enough for me but the GPU was far too powerful for my current needs.

Since AMD Kaveri CPU's were supposed to have a powerful iGPU, I decided to go for it.

Case - Cooltek Coolcube Mini
Motherboard - ASrock FM2A88X-itx+
CPU - AMD 7850K
CPU cooler - Arctic Cooling Freezer Extreme
Memory - G.Skill Ares 2133 MHz 8 GB kit
SSD - Toshiba 256GB mSata
PSU - PicoPSU 160XT with ~190 W brick
Fans - 2 x Scythe Slipstream 500 rpm
Computer dimensions: 20cm x 20cm x 17cm

Here's what it looks like.

And now the interesting part. This is what it looks inside.
Pretty cramped. It was a tight fit with only the picopsu connected and it got worse when I put the cooler on. Then It got even worse when I put the sound dampening on.
That's right, the whole case is dampened on all sides. I wanted to play it safe.
Here's the side panel. I left the top open for the hot air to get out. Rest of the air gets out from the open back.

The original fan on the Freezer Extreme wasn't bad, but it had this annoying ticking noise so I replaced it with a 500 rpm slipstream ghetto modded into the cooler.
I tried PWM Glidestream and Noctua fans first but they were too loud and the Glidestream made horrible clicking noise like most PWM fans seem to do...

I also modded the case so that there is now an intake fan on the bottom of the case. The airflow layout is a bit similar to my previous build.
Without this mod there wouldn't have been enough airflow in the case and it would've overheated.
Currently it doesn't have a dust filter but I'm working on it. The fan is secured with silicone fan mounts.

Since the fan need some breathing room I had to lift the bottom up a bit. I used the HDD mounting rubbers on top of the case feet. The HDD screws were perfect for this as well.

The SSD was mounted on the mini Pci-e / msata slot on the motherboard. Didn't need the wlan so this was perfect.
Msata SSD also meant that I didn't need that many cables. There's only two cables from picoPsu: the 4 pin to the motherboard and the power cord to the back.

Now for the power figures:
Idle: about 25-35W, normally somewhere near 32W
CPU load: (Prime95) 125W
GPU load: (Furmark) 75W
CPU and GPU: (Prime and furmark) 112W
Unigine Valley benchmark: 75W

These seem really strange. The CPU seems to draw a lot of power but the GPU is more efficient.
This iGPU would be perfect with Core i3 or similar.
Anyway, the power figures were pretty good because I think I can overclock the GPU now. Shouldn't be on the limits of the PSU yet.

The CPU got to maximum of 78 °C if Prime. Idle temp is 38 °C.
Couldn't get any proper readings from the GPU.

Cinebench R15
304 cb and 39,29 FPS

Cinebench on my old i3 and GTX660
261 cb and 60,60 FPS

Unigine Valley - basic
23,8 FPS and 996 points
Unigine Valley - extreme
8,9 FPS and 372 points

I guess this was an upgrade from my old computer in a way then. The GPU is good enough for my basic use and occasional Trackmania 2 playing.
It's small, quiet and looks good.

The only downside is that one of the fans still makes some muted clicking noises. Have to figure out something for that as well.

Re: Silent M-ITX box with AMD Kaveri 7850K

Posted: Mon Feb 10, 2014 1:39 pm
by CA_Steve
Pretty build.

Re: Silent M-ITX box with AMD Kaveri 7850K

Posted: Mon Feb 10, 2014 2:00 pm
by sjoukew
Nice build. Thanks for sharing.

Re: Silent M-ITX box with AMD Kaveri 7850K

Posted: Sat Feb 15, 2014 10:15 am
by N-K
Just a quick update.

I felt like the fan speed was still a bit high so I put a resistor to both fans. They now run at 430rmp and 410rpm. It's much better.

There seemed to more headroom thermally so I made some OC test.
I OC'd the GPU from 720MHz to 960MHz and the RAM from 2133MHz to 2400MHz. Had to rise the voltages just a bit, but not too much.
Cinebench gpu test went from 39,29fps to 49,17fps.
Valley extreme bench went from 8,9fps and 372 points to 10,1fps and 418 points.
Power consumption went up about 7W during Valley test.

I also tried overclocking the CPU first but that made it draw a LOT more power so I put it back. The CPU is good as it is.