One Terabyte Disk Drives Pre-Announced
According to Cnet a Terabyte drive to debut later this year. They quote Seagate and Hitachi Global Storage execs talking about their intention to announce one TB drives later this year. 2007 delivery is implied, in case you were thinking you could put one under the Christmas tree.

The usual questions arise: Who needs a one TB drive? Is one TB “too big”? Why does the storage industry persist in labeling disk drives using powers of ten (1000) instead of powers of two (1024)?

A Trip Down Memory Lane
The first one gigabyte 3.5″ disk drive came out in, if memory serves, 1993. Since there were still 5.25″ disk drives shipping with larger capacities, there wasn’t much question that people could use the capacity. Yet it was more expensive per byte, so the really cost sensitive folks, like EMC, stayed with the larger form factor. In fact, by the late 1990’s EMC was almost the sole customer for 5.25″ disks, taking something like 90% of the industry production.

For Databases, Disk Drives Are Always Too Big, Until They Aren’t
The database people felt that these drives were “too big” – somewhere another DBA is saying that about these drives – even as today they happily use 146 GB FC drives. When 18 GB drives came out, I had customers who insisted on buying 9 GB drives because 18 was “too big”. Perhaps it does take the database developers a while to figure out how to use the larger drives.

A Whole Gigabyte On A PC
In 1993 I couldn’t imagine what one would do with a gigabyte on a PC. I’m having that problem today with one TB on a PC, although I know I could rip my entire CD collection into a lossless format and easily use up even more capacity. Oddly enough, I won’t do that until I have some sort of backup capability, since I don’t want to invest the work in ripping everything only to lose it in a drive crash. So I’ll need something like 3 TB of home storage for that job.

Smaller Is Better, So Why Isn’t It Cheaper?
What I am wondering is when the industry will go to the 2.5″ form factor completely and drop the 3.5″ drive. Related to that I wonder why 2.5″ drives are so much more expensive than 3.5″ drives. Check it out yourself: a 40GB 3.5″ costs about 2/3 that of a 40GB 2.5″. The material costs should be lower, the motors smaller and cheaper, shipping and distribution costs lower. The read/write head cost would be the same, but not more.

Even the learning curve effects shouldn’t be all that huge given how many 2.5″ drives are built for laptops. Margins are higher, but that can’t explain the entire delta either. So what causes this huge differential? I sure hope the vendors aren’t getting together in some back room somewhere and divvying up the market. That would be wrong, illegal and very, very stupid.

I would appreciate it if a reader from the industry would explain this in a comment. Use an alias and bare all – I’ll never tell who sent me the email.

When Will We Switch To 2.5″ Drives?
I’ve been wondering about this one for a while. In The Innovator’s Dilemma, a must-read book for every storage aficionado, Christensen makes the case that form factor changes have been the prime mover behind the rise and demise of most disk drive companies. Now that we are down to so few vendors I doubt that will happen again. Most vendors make all sizes, unless, like Toshiba, the specialize in small form factors.

Time For The High-Performance Enterprise 2.5″ Disk
When I was with DEC’s StorageWorks group, the DEC disk drive folks designed a high-performance enterprise 2.5″ drive. They built some mock-ups of applications, such as an entire RAID array in a 5.25″ form factor. At the time the only interest was for laptop drives, where power consumption, not performance, was the critical success factor. So that effort went nowhere.

Yet it may be time for a change. Power issues are looming larger, and smaller drives are more efficient. SATA interconnects lend themselves to plugging drives on motherboards or into backplanes. The scarcity of accesses relative to capacity also points to a move to a smaller form factor. Ultimately though, it may be the continued market share gain of laptops and small desktop PCs that will provide the final push to EOL 3.5’s.

It’s The Capital Investment
Why? Because as production goes up, costs go down. Assuming the vendors aren’t engaged in price-fixing – never a totally safe assumption in the storage business – as the shrinking cost differential leads more customers to buy them and they overtake the current leader. The Mac Mini is an example of a “desktop” system using a 2.5″ drive. A Gartner Group report last year 2.5″ drive factory utilization is almost 88%, which suggests that the vendors are selling almost everything they can build. Nor does it seem they are rushing to build more capacity, unlike the LCD makers. Darn.

Question: Is Google Driven by GB/$ or GB/Watt?
Historically, it has been GB/$, not maximum capacity. With the focus on power and cooling (DC power for the data center, anyone?) dropping 3-4 watts off of 100,000 servers would save some real money – even with cheap Columbia River hydropower. Not to mention how much more tightly servers could be packed. I’m sure someone at Google has looked at this. If they moved that way it would be a big boost for the 2.5″ enterprise drive.

OK, Why ARE Disk Drives Rated In Powers Of Ten?
I’m not sure anyone really knows, but this gentlemen has one of the more entertaining theories. For the record, the terms kilo, mega, giga, tera, peta, exa, zetta and yotta officially refer to powers of 10, not powers of two. So the drive marketers are, for once, on the side of the angels.