Chris, Maybe there's a couple of points that we just are going to disagree on. Please enlighten me on what I'm missing here (are we discussing different technologies other than MO?), but a couple of quick quotes and the full story about MO's from May issue of Byte Magazine:
"Magneto-optical (MO) drives are a durable, transportable medium for backing up and archiving large amounts of data permanently." Backing up and archiving. No mention of primary data storage.
"In a way, MO drives provide limitless storage capacities, because you can remove the cartridges after they run out of space and replace them with new ones." Run out of space and remove the cartridges and replace them. That means they are not erasable.
"Despite their advantages of random access and low per-megabyte costs, optical drives have not gained widespread acceptance, because when compared to traditional magnetic hard drives, they've been high on price and short on performance. The 5-1/4-inch drives that we compared range in price from $649 to $3100, with the average price being about $2285. Tape-backup devices are still less expensive..." I think its clear by Byte's review that MO is a backup, archival device not a on-line/near line device.
Directly from BYTE Magazine
Magneto-optical (MO) drives are a durable, transportable medium for backing up and archiving large amounts of data permanently. For this reason, digital audio and video, graphics, color-prepress, medical, and other professionals have chosen high-capacity optical drives as a standard backup solution.
In a way, MO drives provide limitless storage capacities, because you can remove the cartridges after they run out of space and replace them with new ones. You could say that the sky's the limit when you hear about optical-storage solutions like Pinnacle Micro's optical-library systems, which can hold up to 5 TB of backup
data.
Despite their advantages of random access and low per-megabyte costs, optical drives have not gained widespread acceptance, because when compared to traditional magnetic hard drives, they've been high on price and short on performance. The 5-1/4-inch drives that we compared range in price from $649 to $3100, with the average price being about $2285. Tape-backup devices are still less expensive, with the exception of some 8-mm tape drives. But the performance of optical drives has improved, and their storage capacities should be even greater in the future.
During our hands-on tests, the 5-1/4-inch drives with the fastest throughput in NSTL's InterMark benchmarks fared best. We found this evident in our best-overall choice and high-performance winner, the Pinnacle Micro Apex 2.6GB drive ($1695), which zoomed through our suite of benchmarks. Coming in second and third in performance were the Olympus Image Systems PowerMO 2600 ($2199) and Maxoptix T4-2600 ($2525) drives, respectively. With a capacity of 2.6 GB, the T4-2600 exhibits excellent read-and-write service times with little CPU utilization. The PowerMO 2600 and the T4-2600 (both SCSI-2 units) had a throughput of 2.39 and 2.18 MBps, respectively, in our sequential tests.
Sony's CMO-R544 ($2995) and CMO-R531 ($2695) are also two strong performers--the first supports a capacity of 2.6 GB, while the second is limited to 1.3 GB--with 3600-rpm rotational speeds and SCSI-2 connectors. While there's no way for us to substantiate the claim without tearing a rift in the space/time continuum, Sony says the rewritable media will last 100 years. Panasonic's LF-7300A ($2995) is a 1.3-GB drive with a SCSI-2 connector and 512 KB of read-ahead buffering that boosted its performance to sixth-best.
The Pinnacle Micro Sierra 1.3GB ($1495), Liberty Systems 115M01.3 ($1999), and Plasmon Data RF6920e ($2275) are relatively inexpensive drives that showed lower-end performance in our tests. The three opticals have rotational speeds between 3000 and 3600 rpm, which could explain their close performance scores. Although they didn't knock us over with high-performance numbers, they're more cost-effective solutions for grabbing big chunks of data with
random-access searches.
A newer lower-cost, but lower-capacity, technology is phase change. Panasonic's PD/CD-ROM LF-1000AB drive is the only dual-purpose, phase-change (PD) drive that we tested. You can use the desktop unit as a quad-speed CD-ROM drive for your system, and it also reads and writes to 650-MB removable optical disks (a pack of five disks costs $300).
The PD/CD-ROM drive--which stood up to most MO drives in random-write service and data transfer rates but had the slowest random-read service times in our tests--is a good data-storage format for multimedia files. Compaq plans to incorporate the drive into its Pentium Pro multimedia computers. It's a cost-effective, dual-purpose drive that costs $649 and has 650-MB capacities.
Finally, we're seeing the latest advances in optical technology, and the data transfer rates of optical drives are being boosted even more. These new advances stand out in Pinnacle's latest offering, the Apex 4.6GB drive (see the article "Pinnacle's Apex 4.6GB Serves Up a Heaping Platter"). The drive uses Direct Overwrite media, which applies an MO technology called Light-Intensive Modulation Method (LIMM). This allows a single-write pass instead of a two-write
pass, which makes writes the same speed as reads.
Today's MO drives also use red-laser technology, the lowest frequency on the light spectrum. The development of blue-laser opticals later this decade will expand the bandwidth so that optical drives will be able to support 100 GB of data. Exciting technological advances like these have analysts predicting a tenfold increase in optical-drive sales over the next two years.
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