Stacker AT/16. (file management software) (Evaluation)
by David English

I should admit up front that I'm highly prejudiced about this product. I've already called Stacker 1.0 one of the all-time great software programs. Now Stacker 2.0 and Stacker AT/16 come along with even more features. I'll try to restrain myself but I'm likely to gush with superlatives.

Stacker compresses the data on your hard drive, giving you-on average-twice the available storage space. If you have a crammed 20MB hard drive, Stacker could turn it into a more roomy 40MB drive. Once you install the software, it works in the background. You basically set it and forget it.

Stac Electronics currently offers four different Stacker products: Stacker 2.0 (the software-only version, $149), Stacker XT/8 (Stacker 2.0 with an 8-bit coprocessor card, $199), Stacker AT/16 (Stacker 2.0 with a 16-bit coprocessor card, $249), and Stacker MC/16 (Stacker 2.0 with a microchannel 16-bit coprocessor card, $299). The software-only version is perect for laptops. The notebook computer I'm writing on right now has a 60MB drive that Stacker 2.0 has converted to a 110MB drive. But don't just take my word for it; both Central Point Software and Symantec license the Stacker software compression technology for their bestselling backup programs: PC Tools Backup and Norton Backup.

So why use Stacker with a coprocessor card if the software works so well by itself? The card offers significantly faster performance. On my 20-MHz 80386 computer, the software-only version caused the hard drive to run about 35 percent slower than it did before it was compressed, while Stacker AT/ 16 caused the hard drive to run only about 5 percent slower. The card also offers a slightly better compression ratio. On the same 386, Stacker AT/16 achieved a 2.1 : 1 ratio compared to Stacker 2.0's 1.9 : 1 ratio. In addition, the card has no jumpers, switches, or interrupts to worry about--like the software, you basically set it and forget it.

The AT/16 card uses a new compression chip that runs 39 percent faster than the chip used by the Stacker 1.0 8-bit card. And the new Stacker 2.0 software is as much as 30 percent faster than version 1.0, can take up as little as 14K of conventional memory (or can be loaded into high memory with DOS 5.0 or a memory manager program), includes a special disk-optimizing program (regular defragmentation programs won't work), and can compress floppies, RAM disks, and Bernoulli disks, as well as hard drives.

Is Stacker for you? It depends on your computer. If you have a lot of compressed files on your hard drive, such as ZIP or GIF files, your compression ratio could be well below the 2 : 1 average--making Stacker much less of a bargain. And while my 386 ran just 35 percent slower with the Stacker 2.0 software and a mere 5 percent slower with the Stacker AT/16 software-and-card combination, a much slower XT compatible with a 68-ms hard drive could run as much as 500 percent slower with the Stacker 2.0 software and 200 percent slower with the Stacker XT/8 software-and-card combination. To continue, the comparisons, you can expect a 10-MHz 286 computer to run about 400 percent slower with Stacker 2.0 and about 50 percent slower with Stacker AT/ 16. Clearly, the faster the processor, the faster Stacker can compress and decompress your files.

If you have a 386 or 486, Stacker AT/16 is a no-brainer. Not only will it compress your current hard drive, but it will essentially double any hard drive you buy in the future. If you have a 10- or 12-MHz 286, the decision is tougher, as you'll have to choose between size and speed for your hard drive.