External RAID 1 extremely slow

[ssdnoob]

OK, so I've got a basic WD Mybook enclosure set up with two 750 GB drives in Raid 1. This thing has always been incredibly slow to write to. Yeah, I expect 'slower' writes when the device is doing constant disk synchronization, but what I'm getting from this thing seems ridiculous.

It's connected to my home network via ethernet cable through a good, late-model switch.

The max write speeds I get are 3 - 3.5 MB per second. I can get better than that with a USB 2 drive connected to my PC.

Why is this dern thing so slow? Anything I can do to speed it up?

[LarkStarr]

You're still writing to a single drive bus over a network to two separate disks in software RAID - There's going to be overhead to deal with.

Can you detail your network more? Are you on a 100mbit/sec link to your router? Switch doesn't particularly matter except for bottlenecks (100mbit too?) it's all got to go through the router anyways. I'm guessing 100mbit because the speeds you're getting is typical for that speed.

[ssdnoob]

Yeah, everything is 100 MB/ps...and I get a whopping 3 - 4 MB ps write-rate to the drive.

[dandelioneater]

100Mb/s ~= 12.5 MB/s (maximum theoretical ''speed'')

What kind of files are you writing? lots of smaller ones or movies or something?

On my Dlink 325 NAS with Raid 1 WD green Drives, I get about 30MB/s transfers over a gigabit connection.

Considering that gigabit is 10 times ''faster'' than 100Mbit, I think 3-4MB/s on your connection is accurate.

[ssdnoob]

Generally backing up a local-pc drive full of digital pics, mp3s and miscellaneous stuff.

[supaflyx3]

Yeah that sounds about right, if you were moving large files the speed would be much faster