Remote Disk
I've been through my fair share of HDD's and have tried a couple different NAS drive bays. I have always ended up being a little disappointed for various reasons (most of which has been trying to find a dual drive enclosure with gigabit ethernet support and RAID for a reasonable price). I came across the Western Digital World Book II Terabyte drive at Costco today for $344. It was a bit steep, but try finding a Terabyte of SATA twin drive's PLUS an enclosure that supports gigabit ethernet anywhere.

I'm still trying to get a good feel for it. It is only getting about 10% efficiency of the gigabit bandwidth on my computer for some weird reason, and it is taking over 5 hours to copy 83GB of DVD rips...which seems slow. Averaging only 5.3MB/sec, which is about half what a 100 Base ethernet would do (check this reference for a base line of SATA drive read/write speeds as well as memory and nand flash speeds), let alone a gigabit ethernet setup. Something is VERY wrong. Reading online reviews, it seems to indicate similar problems.

Figure about 35MB/sec for R/W access on a SATA-150 drive locally (this can range from 20-50MB/sec depending on where you are on the plattern). Also, figure on about 60-65MB/sec for R/W access on a SATA-300 drive locally (again, depends on where you are at on the plattern). Figure a typical USB flash drive is about 5MB/sec, and 100-Base-T is about 12MB/sec. Figure striped SATA-150 is roughly 70MB/sec. Main memory DDR2 pushes 5-6GB/sec and gigabit ethernet pushes 125MB/sec. Firewire is ~48MB/sec. Raid-0 (striped) SATA-300 is roughly 100MB/sec. Puts things in perspective.

So, I returned the World Book and bought a Dlink DNS-323 NAS storage and put a 500GB Sammy SATA-II drive in it. Even this NAS is handicapped by less than stellar write/read speeds, but at least it is one of the higher performers I could find on Tom's Hardware. Seems like the dedicated chip doing the conversion from the network traffic to the SATA interface is the biggest problem. Hopefully they can improve it with improvements on the firmware, which is running GNU public code that they said is woefully brute force and not very optimized. This new unit is averaging 18.3MB/sec on sustained write transfers (and about 31% utilization of the gigabit ethernet port). About 3x more than the world book.


- posted by Jeff @ 3:49 PM | 0 comments