At Macworld, Connectix showed their newly-released version 3.0 of Virtual, which implements virtual memory on the Mac. Although Connectix has had versions of Virtual 3.0 running on various accelerators that are incompatible with System 7's built-in VM (virtual memory), the generic version of Virtual 3.0 had been plagued by delays.
Now that it's out, why would you want it? Frankly, because it works the way virtual memory should work, quickly and without using a ton of disk space. I've never used VM seriously because like many people, I'm constantly low on disk space. If you have 8 MB of RAM and wish to add 5 MB to that for a total of 13 MB, you have to have a full 13 MB of free disk space for the swap file that holds the contents of memory that won't fit in the real RAM. That's a waste of disk space. Virtual 3.0 can work like that too, but it also has a DiskSaver mode that uses the amount of disk space equal to the amount of memory you request. In our example above, where you have 8 MB of real RAM and want 5 MB more of virtual memory, Virtual 3.0 can give you that total of 13 MB and use only 5 MB of disk space.
The other reason to use Virtual 3.0 over Apple's VM is that even in DiskSaver mode, Virtual is faster. In the tests I saw on identical PowerBook 170s, Virtual 3.0 was noticeably faster. I hope to do a few simple speed tests (although it's a major pain for me to turn on VM since I seldom have much free disk space) once I have Virtual 3.0 to evaluate. I was warned that some benchmark programs are fooled by Apple's patches so the results appear faster than real RAM. The safe route for benchmarking virtual memory, then, is the low-tech stopwatch.
Those of you trying to use virtual memory on a PowerBook know what a battery hog VM is. Virtual 3.0 avoids this problem by turning off when the PowerBook is running on battery power (I hope there's an override for this, just in case).
My conclusion is that if you rely on virtual memory, and especially if you can't easily free up lots of disk space, you will like Virtual 3.0. If you only turn virtual memory on occasionally and you have lots of free space on that gigabyte drive, it's probably not worth the money for Virtual. And of course, just like with compression programs, if possible, the best alternative is to drop more SIMMs in your Mac. Virtual 3.0 lists for $99 and should be readily available from dealers and mail order vendors. Registered owners of Connectix's CPU can buy Virtual 3.0 for $19 (plus shipping and tax where applicable) by calling them and asking nicely.
Connectix -- 800/950-5880 -- 415/571-5100
Connectix propaganda -- firstname.lastname@example.org