Can two Ultra2 SCSI Cheetah's outrun a single Ultra ATA/66 Barracuda?

My last hard drive test revealed that a single Ultra2 SCSI drive on an Ultra2 controller wasn't any faster than a Ultra ATA/66 drive on an ATA/66 controller. I promised to follow up with a test of two Ultra2 SCSI drives set up in a striped array using SoftRAID. Here's the results:

LONGER BAR is FASTER. RED BAR IS FASTEST.

 

 

 

 

Conclusion & Commentary
Dual LVD "Ultra2" SCSI drives in a striped array on an Ultra2 controller run significantly faster than a single Ultra2 SCSI drive or an Ultra-ATA/66 drive.

This is no earthshaking discovery. What is earthshaking is the fact that it costs over $1000 to create such a SCSI array (2 drives, 1 controller, RAID software). You have to ask yourself, "Is it worth spending 5 times as much to go a maximum of 2 times faster?" And is the cost justified?

In the days of digital video capture, I would question whether disk speed is critical since you can capture in time lapse mode. And with a G4 Sawtooth capable of 1 gigabyte (or more) of RAM, you would hardly need a Photoshop scratch disk.

Still some readers argue they REALLLLLY need lotza drive speed. If that's true for you, then SCSI is the way to go.

 

Big MAHALO to MacGurus for the use of one Cheetah and a Miles2 Ultra2 controller.

 

Test Configurations & Procedures

• All drives were tested on a G4/400 Sawtooth with 256MB of RAM running Mac OS 9. Disk cache was set to 512K to purposely nullify the effects of disk caching on results.
• Test drives included
  Two Seagate Cheetah's 9 gig 10,000 RPM LVD (ST39103LW) with Initio Miles2 Ultra2 adapter (1.05 firmware) and SoftRAID 2.2.1 software to create a striped disk array that lets you read/write to both drives simultaneously, effectively doubling the possible throughput. You need four drives to go 4 times faster. NOTE: If you are using the Miles2 and SoftRAID on a Sawtooth with Mac OS 9 or a Yikes with Mac OS 9, you need the versions of the Miles2 firmware and SoftRAID mentioned above.
  The Seagate Cheetah 9 gig 10,000 RPM Ultra Wide (ST39103LW) with Initio Miles2 Ultra2 adapter.
  The Seagate Barracuda 20 gig 7200 RPM ATA/66 (ST320430A)
  The Western Digital Expert 20 gig 7200 RPM ATA/66 (installed on Sawtooth G4/400 at the factory)
• For the DUPLICATE THREE PHOTOS test, I copied a 27MB Adobe Photoshop document onto each drive and made two copies. Then I timed how long it took to duplicate the three 27MB docs on the same drive. Finally I calculated megabytes per second by with the formula: folder size * 2 / seconds.
• For the DUPLICATE 91MB FOLDER test, I copied the Unreal Tournament Demo folder containing 202 documents onto each drive. Then I timed how long it took to duplicate it on the same drive. Finally I calculated megabytes per second by with the formula: folder size * 2 / seconds.
• The ATTO disk benchmark was run using Express-Pro Tools 2.2 benchmark test with 8MB maximum file size and system disk cache disabled. Sustained Rate is displayed in the charts. Peak rates can be impressive but do not reflect typical drive performance.