October 22nd, 2007

Build the $340 NAS for half the price but double the speed

Posted by George Ou @ 4:42 am

Categories: Build it yourself, Consumer electronics, Energy efficiency - green, Fun Stuff, Hardware, Intel, Microsoft, Networking, Servers, Storage, Vista

Tags: Hard Drive, NAS, Media Center PC, Performance, Power Consumption, Watt, Network-Attached Storage (NAS), Media Center PCs, Performance Management, Storage

The thing that has always bothered me with the NAS (Network Attached Storage) market for consumers is that it’s very high margin yet the products deliver very poorly on performance.  While that might be great for the product manufacturers bottom line, it isn’t so great when you’re the consumer.  Typical NAS devices that allow you to insert 4 to 6 drives cost anywhere between $500 to $1000 yet they only deliver between 15 to 30 megabyte/sec of performance when they imply gigabit (125 megabyte/sec) performance to the consumer in their advertising.

While I think most consumers don’t mind paying a small premium for something that is pre-assembled and easy to use out of the box, I don’t think they’re happy about paying a 100% premium while getting less than half the performance.  I’ve come up with an alternative solution for half the price and more than double the network performance and you can have this solution so long as you’re willing to do a little PC building and you follow my parts list.  If you’re not sure how to build a PC but you’re willing to learn, you can follow this step-by-step picture guide.

For $340 you will be able to build a NAS server running a free Linux server operating system from any of the major distributions like Ubuntu, SUSE, Red Hat, etc.

With a slight upgrade to $442 you can get it with a 5-drive hot-swap SATA backplane cage which I reviewed here.  Note that the SATA hot-swap cage requires some small modifications to the chassis since there is a small metal lip between each 5.25″ drive module.

I do like the feature set and relative ease of use of Windows Home Server (for people not familiar with Linux), but I have been disappointed with the steep system builder price of $185 when the hardware is barely double the cost of the software.  I’m sure the OEMs like HP are getting a much better price for Windows Home Server but that doesn’t really help the home system builders who buy one at a time.

You could run Vista Premium which is around $110 OEM price and that will give you basic network file hosting capability along with the media center capability so this is a great option for people who want Windows.  Linux plus MythTV will also let you do the network file sharing and TV recordings and that’s free if you can deal with Linux.

Double duty as a Media Center PC
Note that you’ll need to borrow a CD or DVD ROM drive to install the OS or you can just throw in a cheap DVD burner for $30.  Having the optical drive might be useful since you can also stick in a TV tuner card and have this system perform double-duty as a NAS and Media Center PC which doubles your utility without spending a lot more money or using a lot more power.  It makes little sense to buy a totally different system for the Media Center PC and waste the extra 60 watts of power to run a separate box.  The nice thing about this arrangement is that you already have all the storage at your disposal for your video recordings and there isn’t a better place to put all your videos.  The other great thing about having a system like this is that you can host additional virtual servers using free hypervisor software from Microsoft and VMware.

System power and performance specifications
This system without the hard drives will consume roughly 42 watts during idle and each hard drive you add will add roughly 9 watts to the idle power consumption.  Peak power consumption in the system will be around 75 watts without the hard drives and each hard drive peaks at around 13 watts during busy read/write cycles.  The peak power consumption fully loaded with 6 typical 7200 RPM hard drives is 153 watts during peak CPU and storage operation.  During system power-up, each drive consumes up to 30 watts so it’s possible to see 200 watts of power consumption for a few seconds when the hard drives go from 0 to 7200 RPM so the 300 watt power supply (smallest ATX model you can buy) is overkill.

Note that Western Digital now sells hard drives with half the idle/peak power consumption and the 750 and 1000 GB drives are between $220 and $300.  Compared to 500 GB drives you can buy for $110, the larger capacities are a bit expensive per GB.

Performance-wise you can expect to see about 70 megabytes/sec over a gigabit LAN which is twice as fast as the $1000 commercial NAS devices you can buy over the shelf.  With the new ICH9R RAID controller you can actually expect to see close to 300 megabytes/sec of disk sub-system performance but you’ll be limited by the speed of the gigabit network when you factor in overhead to around 70 MB/sec.  If you don’t have a gigabit switch, they’re as cheap as $36 with jumbo frame capability.  For more on how to effectively configure and use all this capacity, you can read Best storage strategies for the multimedia PC.