Throughput of WD My Book Studio Edition II – 4TB

I have been experiencing performance issues (5 – 20 second delays) with Lightroom 2 grid view when editing 20- 30 MB images across the network.  My conclusion is don’t use LightRoom across a network, and connect the drives using eSATA instead  of FireWire 800.

My Findings:

I use a MacPro to connect via an internal gigabit LAN to a server with a MyBook external hard disk (connected with FireWire 800) .  At first I suspected issues with the server, then the network, but now I believe its just the accumulated inherent speed of all of the components.  The largest bottleneck seems to the Firewire 800 with its maximum throughput of 100 megabytes per second.

When copying 286 GB of images from a MyBook, I measured overall throughput as 62.6 Megabytes (MB) per second.   The copy was taken over a 1GB network between the two Macs.

Although that is not bad, the copy took 72 minutes.  Given that a MyBook II supports eSATA this may be wise configuration enhancement for the future.

Measurements were taken using Apple Monitor.

The hardware configuration is as follows:

• Server Mac Mini – 3GB memory, 2 Ghz single Intel Core 2 Duo. (Macmini3,1)
• WD My Book Studio Edition II – 4TB - configured as Raid 0 – striped across 2 – 2TB drives, connect to the Mac Mini using a FireWire 800 cable.
• MacPro – 8 core. 10GB memory.
• Dlink DGS-1008D 1 Gigabit switch (1000Mbps)

One of the bottle necks seem to be the maximum speed of the FireWire bus transfer – in this case 100 MB per second (800 Mb/s).  I also suspect the bus speed of the Mac Mini bus but have no way to measure that.   Click thumbnail for larger image.

Both memory and CPU have been ruled out as a bottleneck so that left the network, computer bus and MyBook.  I will test the local connection and report my findings.