tiny inctel i5 U520 PC

So I’ve been using various laptops at home as ‘servers’ for many years. Up till recently this was an old Thinkpad R60, upgraded to a core 2 duo CPU, stuffed with two 500GB drives and some external drives. I used it for KVM VM’s and as a DLNA server amongst other things. It satisfied my need for a reasonably quiet server that I could run a few VMs on. The lack of ram expansion was the main annoyance (only up to 3GB)

So the R60 had been chugging away for a few years, when I came across this i5 U520 little PC on aliexpress. It seemed quite good;

  • $103 plus postage (admitedly $30 or so for postage)
  • You get the i5 CPU, built in PSU and power brick. I bought the barebones system, but you can buy it with various amounts of RAM and mSata internal drives.
  • It takes up to 16GB of DDR3 memory. I did test this, and it does work with two 8GB DDR3 DIMMs (UPDATE. I am not so sure now. Originally, this was a quick test to see if it was recognised by the BIOS. It does recognise 16GB, but originally I put a 4GB DIMM in as the 16GB I had were being used in another system. Recently I tried the 16GB again, and the machine eventually crashes, so I tried memtest, and this fails immediately. It could be the DIMMs I am using. Not sure).
  • As well as the mini pci-e/mSata connector on the motherboard there are two normal SATA connectors, and the PSU has a few spare power things such that you can probably plug two drives in (there is one SATA power connector and one regular 4 pin connector like you get on 3.5″ drives).
  • Has VGA and HDMI out.
  • Has almost too many USB 2.0 connectors. Two on the front and 6 or so on the back, plus I think there might be another 4 on the motherboard.
  • It has an external power brick (the size of a laptop charger). I think it is rated at 72W, and the internal ATX PSU is rated at 120W. It’s a 12Volt input type.
  • Gigabit LAN (Realtek 8168)
So I bought it as a bit of a gamble. (For me) usually these cheap little things end up with something seriously annoying. It turned up pretty quickly, and it’s pretty good. First the positives.
The good;
  • It’s pretty small. In some ways it’s better than a laptop server, as you can stack external drives on top of it easily … so you can kind of shove it at the back of a desk or in a corner.
  • The i5 seems fast enough. Some people might be deterred by the 1GHZ clock rate (but it ‘turbos’ up to 1.86GHz), but it seems to chug along nicely. I’ve tried playing a few smallish mp4’s on it and it doesn’t really sweat too much.
  • I can fit one 2.5″ drive inside it. There are sort of mounting holes so that a 2.5″ drive can be mounted along one side. It’s not ideal, but you have the main ATX power cable directly underneath  … which means the drive is not floating as such.
  • I currently have Fedora 19 on it, and it seems to run OK.
The not quite as good;
  • The fan is a bit too loud for me. It’s not too awful, but for me I’ve been trying to figure ways to keep it quiet. I am realistic that trying to make a little 40mm fan quiet is almost impossible. When the little PC was delivered the fan came on at a constant speed and did not change. I thought this was odd (as most modern systems adjust the speed of the fan with load). It turned out the cpu fan was plugged into the motherboards SYSFAN connector, not the CPUFAN connector. So I tried the fan in the CPUFAN connector and the fan did not start spinning at all. I thought ‘oh maybe the CPU is not under enough load for it to come on’, so I generated some load .. but it still did not spin. Odd. I measured the voltage across the CPUFAN connector and it had some volts. Odd. Maybe it doesn’t have enough current to spin it?Anyway, for now, I have the CPU fan plugged in to the SYSFAN connector with a few resistors in series. It’s not ideal, but it keeps it reasonably quiet. The CPU temps are still quite low too. In fact the ultra low voltage i5 has a max TDP of only 18Watts, so the CPU temps seem a lot lower than other CPUs. In fact, when I have had it running with the fan disconnected it doesn’t seem to heat up like crazy.
  • The front power LED is a sort of combination power LED and HDD activity one. It’s one of those  ‘burn your retina out’ bright blue LEDs. Suffice to say it was annoying, and fortunately you can unplug the power and HDD LED connectors on the motherboard.
  • No USB 3.0 ports is annoying in this age of enormous hard drives. Having a 2nd ‘normal’ SATA connector can potentially make up for this if I pull my external drives apart. I have discovered one mini pci-e to USB 3.0 adapter that I might look at later on.

I haven’t tried anything other than Fedora 19 on it. I should try ESXi on it. It would make a nice little ESXi server.

UPDATE (23.11.2013). I started having weird problems with this system not turning on, or a reboot leaving the machine in a turned off state. It turns out this was related to my various attempts to slow the fan down. With the fan spinning slowly or not at all on power on, there isn’t enough load on the PSU for it to power on properly. If I get rid of all the resistors to the fan, then the machine powers on and reboots reliably. Sounds similar to this post about a jetway board and pico psu. The other thing is that I did boot ESXi 5.5 successfully on the inctel. Key tips are 1) embed the r8168 driver into the ESXi iso . And set the BIOS to have your SATA drives in RAID mode even though you are not using RAID (ie. there is some weirdness in the BIOS such that the usual AHCI setting won’t work).