Next, after connecting up the WD MyBook, we used Mac OS X's Disk Utility application to format both drives using the OS' own journaled file system and then to connect the two as a RAID 0 array, presenting both drives as a single 931.27GB unit, with data chunks alternately written on one drive then the other, a technique called 'striping'.
Multi-drive eSATA tests
Results in MBps - longer bars are better
Writing data to the drives and reading it back yielded comparable numbers to the single drive, reflecting the limits of the MacBook's own hard drive. But look at what a difference duplicating data on the external drive set made: using RAID almost doubled the bandwidth. Photoshop users, imagine what that could do for your Scratch Disk usage?
We used Retouch Artists' Photoshop Speed Test action to try it out. Running the actions on a 2142 x 1449 RGB image using the MacBook Pro's hard drive only took 206.63s. Restarting Photoshop CS1 this time using RAID array as the Scratch Disk saw the action run time fall to 172.75s, a 16.4 per cent reduction.
Some Mac users will, not unreasonably, claim they don't need eSATA because Firewire 800 does the trick. That may be true for now, but as Apple showed with its first MacBook Pros, Firewire 800 isn't a given. It's not widely supported beyond the Mac niche, whereas we're seeing eSATA on more and more high-speed external drives and on PCs. eSATA is going to become cheaper - Firewire 800 isn't.
Future-proofing your MacBook Pro - or ExpressCard-equipped PC, if doesn't have an eSATA port of its own - will set you back around £95, not a bad price to pay. It's not for everyone - most of us can make do with Firewire 400 and USB 2.0 for a few more years until Macs get built-in eSATA ports.
Want to take advantage of eSATA and RAID on your MacBook Pro? Sonnet's Tempo SATA Express 34 is an easy way to make it happen.
Sonnet Tempo SATA Express 34
I have one and also have/had problems
I am using the second release of the 17" MBP. I finally got some drivers emailed from the tech support that helped make the system a bit more stable. The express card 34 seating is horrible. Any movement will cause it to pop out. Doing So screws up any disk accesses, as well as blows away the functioning of airport. Airport looks like it is connected, but.. doesn't work. The speed (tested with xbench) is nice, although the limiting factor is the internal interface to the express 34. (I called tech support, as I could not get close to the 3 Gb speeds in a striped array) that my drives claimed to support. I understand that the problems with the loose fitting express 34 card are more apple problems then any manufacturer, as many people are having problems with cards popping out.. Apple really should have an esata port on the machine directly.
Overall it is ok, IF one can take precautions so the card will not be moved. This entails the laptop to be in a fixed position, and can not be used on your lap, like it can with firewire or USB. :( I am using the system with an external array of 5 disks and a multiport connection. Hope this helps others..
I'm using iSCSI at work. It's nice, at 1Gb it's very quick (at 10Gb it's blazing). With 15000 rpm SAS drives it's great. Problem is, it's not cheap. The eSATA is aimed at a single machine. Two different solutions. But at home I have a home built NAS. Right now it has a 300 GB drive. I'm about to replace that with a 750 or wait a little longer and get a 1 TB drive. "That will be all the disk I ever need". (Also said when I bought a 10 GB drive for my desk top).
Now I've heard about people building iSCSI home solutions using a Linux box, but that's a technical solution beyond the means of most users.
Re: Different standards...
There is a reliable ethernet Storage standard, it's called iSCSI, the majority of the major SAN vendors support iSCSI, but notably NetApp are a major iSCSI supplier who recently started producing low end kit for the small business channel (www.sorevault.com). As far as I'm aware OSX supports iSCSI, windows certainly does and it's possible to use either a hardware or software based "initiator" in the form of a Host Bus Adapter or a software driver that works in conjunction with an ethernet controller. It works by using SCSI commands over TCP/IP.