The original system was a Platinum G3/266 Desktop Macintosh with 224 MB of memory, a 5 MB/sec SCSI bus, a 16.6 MB/sec IDE bus, a CD-ROM, and a Zip drive. The SCSI bus has the Zip drive, a tape drive, a 2 GB hard drive, and a scanner. The IDE bus has the original 4 GB internal IDE drive. Two of the three PCI slots have an Ethernet card and a 5 port USB card. (The SCSI 2 GB drive will be removed, and the 4 GB IDE will be kept, partly to provide a backup bootable system. ) The Mac OS was upgraded to 9.0.4.

Additions

A Sonnett ATA/66 interface card was installed in the remaining PCI slot, and an internal IBM 75GXP 46 GB, 7200 RPM drive was installed in the bay above the Zip drive. The only additional purchase required was a sled for the drive. The 75GXP drive is ATA/100.

Installation

The Sonnett card came with a good descriptive installation manual with instructions for a Desktop Mac, a Tower Mac, and the Blue & White/G4 graphite computers. I downloaded the installation manual for the 75GXP from the IBM site; although this was for a PC installation, it was still useful information. (Note: For Beige G3 owners replacing the original hard drive, see my 1998 Illustrated Beige G3 MT HD Upgrade Guide - Mike)

The installation went very smoothly. The formatting was done with Disk Setup 1.8.1. The Disk Setup Help said that the drive would run faster if divided into partions. I created the maximum number of 8 partitions ranging from 3 GB to 10 GB. Having that many partitions makes backups easier to segment/manage.

Performance

The performance testing was done on the system partitions of the SCSI 2 GB (SYS), the IDE 4 GB (G3-HD1), and the new 75GXP (G3-HD). I thought it would be interesting to compare the ATA/66 bus with the ATA 16.5 bus and SCSI 5 MB/sec bus to appreciate the tradeoff of add the Sonnett card.

I was surprised by the variation of performance among the various partitions on the new drive. The speed decreased as the partition number increased. (Is this related to track circumference?) This decrease was not monotonic, presumably due to the variation in the sizes of the partitions. Steady state read speed was between 22.41 and 36.07 Mb/sec, and write speed was between 17.79 and 31.97 Mb/sec.

The three partitions which were measured are all bootable partitions, but they are on three separate disks: SYS (old SCSI), G3-HD1 (old IDE), and G3-HD (ATA/66 bus).

Benchmark Performance Charts

At the low speed of the old SCSI bus, plus the scale of the plot, the write graph exactly overlays the read graph; the read/write speeds are identical. The bus is nominally 5 MB/sec.

The original IDE bus is nominally 16.5 MB/sec, and this partition is on the original IDE internal drive.

This is the first partition on the IBM 75GXP drive, and it had the fastest read and write times of all the partitions for this drive.

Real World Measurements

File and folder duplication tests were run for a 20 MB file and a 81 MB folder which contained about 1300 files. There may be some bias because, even formatted with Mac extended format, the minimum size file varied among the hard drives. SYS had files as small as 1K, for G3-HD1 the smallest file was 2K, and for G3-HD the smallest file was 4K. As I recall this has to do with the maximum number of files for HFS+; so the larger disk would have the largest minimum size file.

(Note: Remember the Beige G3's onboard SCSI is only a 5MB/Sec max interface. The onboard IDE is ATA/3 (16.6MB/sec max interface).-Mike)

Test	2GB SCSI (Onboard SCSI)	OEM 4GB (Onboard ATA)	IBM 75GXP (ATA/66 Card)
Duplicate 62 MB file	32	22	5.5
Duplicate 81 MB folder	194	49	30

All times in the table are in seconds.

There is some bias in the PhotoShop measurements because the files were on the test partition, but PhotoShop itself was on a different partition. There is also a bias caused by the decision as to where to allocate the scratch disk for PhotoSop. Allocating it to the same disk/partition as the file being edited slows down PhotoShop; allocating it to a different disk/partition puts less load on the disk/partition under test. For these tests, scratch disk area for PhotoShop was allocated to the partition being tested since that seemed to be the truest test of the drive.

The PhotoShop manual says that since PhotoShop copies its RAM image to scratch disk, it must have at least as much scratch disk as allocated RAM; it recommends 3 to 5 times the size of the file plus 10 MB. For the 62 MB file, that translates to 196 to 320 MB of scratch disk! However on one of the test runs, when I allocated 220 MB of scratch, it said that it did not have enough. If I gave it all of the scratch area it wanted for the 62 MB file, it took 306 MB (with PhotoShop allocated 120 MB of RAM). I ran tests with scratch assigned to the RAM disk, and tests with more RAM allocated to PhotoShop. RAM disk gained at most a 20% improvement in time. The most dramatic improvement was to give PhotoShop more RAM. Since the RAM disk takes memory that PhotoShop could use, it doesn't make much sense to use RAM disk.

The following two tables show PhotoShop results for two cases: (1) PhotoShop allocated 40 MB of RAM; and (2) PhotoShop allocated 120 MB of RAM. All times are in seconds.

(Note: A general rule for optimal PShop RAM allocation is 4x to 5x the size of the image you will be working on. You can see if the swap file is being used in Photoshop by selecting "effeciency" as the option for the lower left edge of the image window. Less than 100% means the swap file is being using-Mike)

-Robert Bradley

(Note the dramatic gains seen from allocating more RAM to Photoshop-Mike)

If you've installed/upgraded a Hard Drive, CD/DVD/DVD-RAM/Tape drive, or removable media drive in your Mac - please post an entry in the Mac Drive Compatibility Database. Include any performance comparison or compatibility info with your report.

Related Articles:

Links to other IDE drive related articles. For general info/upgrade articles on Beige/Platinum G3s - see the Systems page and G3-ZONE.

• Complete Listing of Site IDE Drive/Controller/RAID Reviews/Articles
• IBM 75GXP RAID Performance
• Dual Drive IBM 75GXP RAID Performance
• Maxtor Plus40 40GB Hard Drive Review
• Maxtor Plus40 Tests in a Beige G3
• IDE RAID How-To - Illustrated guide to installing 2- hard drives and RAID software in a B&W G3 or G4 system. (Steps applicable to IDE or SCSI)
• IDE RAID Performance - Is IDE RAID worth the extra cost?
• Acard ATA/66 vs TurboMax ATA/33 Performance
• ACard ATA/66 vs Onboard ATA/33 Mac IDE Real World Tests
• TurboMax ATA/33 IDE Card Review (first Mac PCI IDE controller review from Spring 1999)
• Beige G3 IDE Hard Drive Upgrade guide
• B&W G3 IDE Slave Hard Drive Upgrade guide (read warnings there for rev 1 IDE chip corruption issues)
• Links to IDE standards and definitions (thanks to Jeff Relm)
• Proline's low-cost Proline Velco Attached HD Bracket (Photos from B&W G3 install)
• Complete List of Controller/Disk/RAID Articles (Links to SCSI, IDE and Firewire topics pages)