Intel D945GCLF2 – Dual Core Atom Server Performance and Observations

The Intel D945GCLF2 is a mini-ITX motherboard sporting the dual core Atom 330. The Atom 330 has two cores running at 1.6ghz with an amazingly low 8w CPU TDP rating. A member of the SilentPC forums measured the total system power usage at about 19.8 watts (http://www.silentpcreview.com/forums/viewtopic.php?t=50122). This makes it perfect a lightweight home server since it won’t run your electricity bill through the roof and because it’s just the right amount of power for the job.

Typical home server duties include:

• File sharing
• File downloading/uploading
• “Unrar”ing (uncompressing) files and repairing archives using par
• Streaming media/audio
• FTP server
• VPN server

The server I built uses an Intel D945GCLF2, 1GB RAM, and two Samsung 1.5TB 5400RPM drives running Ubuntu Server 8.10. It’s main duties are:

• File sharing via Samba
• Usenet downloading using SABnzbd
• Server monitoring and admin web interface using Webmin
• FTPS server for small file transfers over the internet

File Transfers

One of my main worries was that the Atom 330 would bottleneck file transfers. I then pleasantly discovered that the Atom 330 has no problem handling large file transfers over a gigabit connection.

The output seen directly below is a benchmark of local file transfers. I’m using the Linux “dd” utility to write files of various sizes to the disk locally. As you can see, the write speed averages at about 80-85 MB/s.

prochobo@server:~$ sudo dd if=/dev/sdb1 of=/dev/null bs=512 count=1000000
1000000+0 records in
1000000+0 records out
512000000 bytes (512 MB) copied, 6.98248 s, 73.3 MB/s
prochobo@server:~$ sudo dd if=/dev/sdb1 of=/dev/null bs=512 count=2000000
2000000+0 records in
2000000+0 records out
1024000000 bytes (1.0 GB) copied, 9.84069 s, 104 MB/s
prochobo@server:~$ sudo dd if=/dev/sda1 of=/dev/null bs=512 count=2000000
2000000+0 records in
2000000+0 records out
1024000000 bytes (1.0 GB) copied, 11.9971 s, 85.4 MB/s
prochobo@server:~$ sudo dd if=/dev/sda1 of=/dev/null bs=512 count=4000000
4000000+0 records in
4000000+0 records out
2048000000 bytes (2.0 GB) copied, 23.6592 s, 86.6 MB/s
prochobo@server:~$ sudo dd if=/dev/sda1 of=/dev/null bs=512 count=8000000
8000000+0 records in
8000000+0 records out
4096000000 bytes (4.1 GB) copied, 47.5238 s, 86.2 MB/s

The speeds shown above are the result of writing to the disk locally. Here’s what happens when reading/writing files to the disk over the network:

Read from server/write to client disk:

Read from client disk/write to server:

CPU Usage while writing to server disk over network:

Not bad, not bad at all. File transfers run very quickly, as you can see. However, you’ll notice that the client to server disk write speeds aren’t quite up to snuff. 41MB/s network write speed vs 85MB/s local write speed to the server drive.

SABnzbd – Par repair and unrar extraction

Another thing I was worried about is the performance during repair and unrar operations. I use SABnzbd to download from Usenet and I didn’t want the repair/unrar operations to take forever. However, I was wrong. The archive repair and uncompression didn’t t take long at all! Here are some results (some output blurred for privacy):

The first file was just under 8GB and took 4 minutes to verify, and took about 10 minutes 30 seconds to unpack.

The second file was a little over 8GB, took 4 minutes to verify, and took about 15 minutes to extract to 12GB.

For smaller files, say ~1.5GB in size, archive verification usually takes one minute while the extraction takes about 2 minutes.

Previously, I used SABnzbd on my desktop, which was a bad idea. As soon as the repair/unrar operations kicked in, the hard disk became heavily accessed, which brought my system to a crawl. Offloading this work to a server eliminates that problem and works fairly well.

Other uses

I strongly urge people running Linux home servers to install Webmin. Webmin is a web administration interface letting you do nearly everything you can think of. You manage log files, manage configurations, configure services, and there’s even a file manager to download your files over the internet.

In addition to Webmin, I’ve also configured an FTPS service using vsftpd. Proftpd is also a very popular choice. The FTPS service is mainly utilized for syncing my Keepass database, but I also use it to access documents from time to time.

HTPC Usage

Running Ubuntu Server 8.10 and XBMC works great for standard definition (SD) content. Divx and DVD rips play perfectly. However, the onboard Intel GMA 950 graphics processor cannot handle 720p content and above. The video stutters and the audio soon becomes out of sync.

Flash is hit or miss. In windowed mode, videos on Youtube play just fine. However, once you enlarge the video to fit the full screen, the video lags and stutters.

For HTPC use, I read that some people use a PCI (not express, just regular PCI) video card, such as an Nvidia Geforce 8400GM to decode 720p and 1080p content. However, this could be a problem with only one PCI slot.

Things to look out for

There’s a bug in Ubuntu 9.04 that intermittently shuts down the on board network card during heavy activity such as during file transfers:

Aug  9 10:19:37 server kernel: [  144.010039] NETDEV WATCHDOG: eth0 (r8169): transmit timed out

Bug thread here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/76489

In order to remedy this, you can either downgrade to 8.10, or use a different network card in the PCI card slot. However, if you use an alternate PCI network card, you won’t have a slot for a PCI video card. I opted to just use another network card since I didn’t want to do a complete reinstall.

Also, the GPU fan is quite noisy. I replaced it with a 40mm Scythe Mini Kaze fan and now the loudest part of the server are the hard drives.

Conclusion

You don’t need a quad core processor and 4GB of RAM for a home server. The Intel Atom 330 runs fast enough for all the services noted in this article, and uses less power than an incandescent light bulb. One of the only features the Intel D945GCLF2 is missing are additional SATA ports and a better on board graphics processor. But hey, for $80 for the motherboard and CPU, you really can’t complain.

Tagged as: intel atom, server