ASRock AM1B-ITX + AMD Kabini Sempron 3850 Linux Notes

Earlier this summer I built a new home server using an ASRock AM1B-ITX motherboard and a AMD Kabini Sempron 3850 CPU.

To make a long story short, this motherboard doesn’t work well for my intended use as a headless Linux server. The problems are manifold and interconnected:

  • If I boot headless, it decides the integrated GPU isn’t being used.
  • Once it decides the integrated GPU isn’t being used, it tries to use a PCI Express GPU, which it doesn’t find.
  • At some point, it also reactivates compatibility mode.
  • With compatibility mode activated it is, ironically, incompatible with my combination of hardware.
  • The combination of all of the above means that it won’t boot headless.


These issues weren’t immediately obvious. The storage issues showed up early on, once I added the extra drives, but others took longer to show their face because, while I’ve been using it for its intended purpose for a couple of weeks now, I only just finally got around to moving it off the corner of my desk and into its final position on a shelf in a closet. I assumed this move would be relatively uneventful. It wasn’t, it was frustrating and tedious.

By way of context, I thought I’d give a few more details on my installation.

The system drive is a 256gb Crucial MX100 SSD. The root volume is relatively small, like 8GB or so. There is a small swap partition, an EFI partition, a good chunk of unused space  as a lazy sort of SSD over-provisioning for longer life, but the bulk of the drive is set aside as for SSD caching of various volumes using Bcache. The root volume is un-exotic though, straight ext4. I’d intially set the system up to boot using legacy BIOS, but after some backflips, managed to convert it to use gpt partitions, and UEFI booting.

The SSD is connected to the main SATA3 controller on the Kabini SoC, as is a 3TB Western Digital Red drive. There are two other motherboard SATA3 ports provided by an ASMedia chip. These are attatched to  3TB and 1TB WD Green drives. None of this is very exotic.

The CPU/Motherboard has integrated video, which I had attached over DVI to an external monitor. The machine is intended to run headless, but I want to run some OpenCL stuff on the GPU, so I had to install video card drivers. By default, the system installed the open source radeon driver, but, from what I could tell, this doesn’t yet have OpenCL support, so I switched to the proprietary binary flgrx driver.

With that background out of the way, I’ll detail the many annoyances I’ve had with this system.

First off, I found that it would often boot slowly, or hang all together, and this tended to involve drives connected to the ASMedia SATA controller. Sometimes it would hang or take forever to detect connected drives. Other times, it would hang on the main BIOS screen, while lighting an activity light on one of those drives. After some trial and error, I figured out it worked much better if I disabled “Compatibility Support Mode” (CSM) in the boot section of the BIOS setup.

The next problem came when I shut the machine down, detached it, and moved the machine to its final location. When I rebooted it, it emitted 5 sharp beeps and then didn’t seem to do much of anything else, except light up the activity light on one of the drives connected to the ASMedia controller. I tried leaving it for a while, to see if it proceeded to boot, but finally gave up and tried resetting it. That didn’t work either, no beeps this time, but it still seemed to hang with the drive light activated. I moved it back to the desk, hooked up the monitor and tried to figure out what had gone wrong.

I found that the BIOS seemed to have reverted back to compatibility mode, moreover, the primary GPU was listed as being PCI Express, rather than integrated. A little digging and I learned that the 5 beeps meant “without vga card.” I mucked around a bit more, trying different things, before reaching the conclusion that this board has major problems, at least for my application.

I’m not sure what I’m going to do next. I realize it might be worth disabling the boot recovery mode, because that may be part of the reason it is falling back to a problematic BIOS configuration. My guess is that I may still have trouble with the internal video, but I might be able to address that with an explicit kernel option (assuming that the boot process still continues). Another option is to see if I can hook something to one of video ports that tricks it into thinking a monitor is connected.

My not-so-inexpensive mini-ITX home storage server build

IMG_5779I wrote about the tortuous path I took to building a new home server in an earlier post. Now I’m actually going to take the opportunity to document the build.

First off, the parts list:

My goal was to have an inexpensive, capable, efficient, compact machine to run as a home server as an upgrade to some older Marvel Kirkwood based servers I have. Intel’s BayTrail Celeron CPUs were an interesting option, but I chose to go with an AMD Kabini APU, for a few reasons. Formost among them, it was available as part of a $100 bundle with a case and a motherboard with four 6Gbps SATA channels, rather than the two common on BayTrail boards.

Norco S4-ITX case (top) compared to Coolermaster Elite 130

Unfortunately, the Cooler Master Elite 130 case in the bundle was bigger than I really wanted, so I ended up spending another $100 to get a Norco ITX-S4.

Unfortunately, the ITX-S4 required further upgrades and part-swapping.  The stock fan was amazingly loud at full speed, and because it was a 3-pin fan, couldn’t be regulated by my motherboard, so it was loud all the time. I ended up replacing it was a Arctic F8 PWM fan. The new fan is quieter, at full speed, and I set up a custom fan profile in the motherboard BIOS so it spends most of its time turning even more slowly and quietly.

IMG_5578 IMG_5580A bigger issue is that there wasn’t enough clearance between the stock CPU fan and the bottom of the hard drive cage, which made it impossible to install the motherboard.

I was able to fit it in by removing the hard drive cage, but this resulted in about 1mm of clearance between the top of the can and the bottom of the drive cage.

I considered many options. The AM1 platform used by the socketed Kabini chips like the Sempron I used is still relatively new, and its a low cost platform, so 3rd parties haven’t been rushing to produce aftermarket heatsinks. I looked at the possibility of modifying a heatsink intended for another application, and considered grinding 5mm off the stock heatsink.

IMG_5769I finally realized that the stock fan was 15mm thick, and so I fitted a 10mm fan instead. Cheap and easy, so I did it. This seems to work pretty well, but I’m considering either cutting a hole in the bottom of the drive cage to improve airflow, a wider, lower-profile heatsink with a larger fan, or making some sort of baffle to improve airflow so I can keep the chip cool at lower quieter fan speeds.

Overall, I’m going to have to give mixed marks to the ITX-S4 case. I like the size, and the looks, but there are a number of downsides. In addition to the noisy stock fan, the build-quality is kind of mixed. The sides bow a bit, but the biggest issue is the drive trays. The latching levers feel a little flimsy. I worry I’m going to break something when I insert or remove them.

IMG_5752Even worse, the latches that are supposed to hold the levers closed keep slipping free of the levers. This has happened at least once to each of the four drive trays. If it happens again I’m going to need to resort to some superglue.  This is completely unacceptable for a $100 case!



A few more notes on things that didn’t work out as expected. I purchased an IO Crest 2 Port SATA III PCI-Express x1 Card so that I had an extra SATA channel available to take advantage of an internal SSD bracket, saving the drive bays for 3.5″ drives. Unfortunately, the machine resets during the linux boot process, shortly after identifying devices connected to the card, so I’ve set it aside for now.

I also tried Rosewill 19.7″ Serial ATA III Blue Round Cables, thinking that the round cables would be easier to route. They weren’t. First off, I missed the fact that the ones I bought have 90° connectors on one end, which doesn’t work given the configuration of ports in the drive cage.  In addition, the 180° connectors were too thick for the close spaced SATA ports on the the motherboard. Moreover, the cables were still quite thick and stiff. I found it easier to use standard flat SATA cables. Some of the ones I had on hand were a tight fit because of the length of the molded connectors, so I picked up some matching cables with shorter connectors.



Overall, I’m pretty happy with the way the project turned out so far. With a 3.5″ Western Digital Green HDD, two surplus laptop drives (one 7,200 RPM the other 5,400), and the SSD, it idles at about 25W. With cpuminer and sgminer mining litecoins on the CPU and GPU, respectively, it uses ~45W. At full-load on a warm day the fans are a little noisy, in particular, the CPU fan has to spin at nearly full speed, (4,500 RPM), to keep it under 60°C, otherwise the CPUs thermal throttling will kick in, which seems to shave ~5W off the load by dropping the CPU and GPU clocks by 20% or so.

Next step is to install Debian and migrate over data and services from my old server. In the longer run, I may revise this build with a BayTrail build for lower power consumption and noise.