by Don Engstrom

My first Mac was a Quadra 660AV. I still remember the day when I upgraded it to a "whopping" 32MB RAM, more than I thought I would ever need. These days my workhorse machine is a G3/266 PowerBook with 128MB RAM and, believe it or not, even this amount still feels cramped at times.

Enter RAM Doubler 9 which extends your memory up to 3 times the amount of installed physical RAM or 240MB, whichever is less. Apple's virtual memory which comes built in to the system software has a far more generous limit of 1GB or the amount of free hard drive space, whichever is less. Given these facts, RAM Doubler doesn't seem like a worthwhile option for extending your RAM. Read on to find out if this is the case...

Installation/Documentation: The installation process is simple and painless. RAM doubler needs a minimum of 32MB physical RAM to run and as mentioned above, will not extend RAM beyond 240MB. If you have 240MB or more already installed, RAM Doubler will politely tell you that it cannot be used and will quit the install. RAM Doubler also disables Apple's virtual memory as the two are mutually exclusive. Connectix deserves kudos for RAM Doubler's excellent printed documentation. The manual clearly outlines the various control panel settings, how RAM Doubler works its magic, and general memory management tips. The control panel is well organized and contains "context sensitive" help to bring you up to speed on its use.

RAM Doubler uses three different techniques to extend the amount of usable RAM.

• Reallocation - This is the first, and preferred, step. If you have ever looked at your "About this Computer" window (accessible via the Apple menu when the finder is active) you will have noticed most applications use less RAM than the amount allocated to them. RAM Doubler takes this unused RAM and makes it available to the system. This approach is ideal as there is no performance hit involved.
• Compression - If reallocation is not sufficient, RAM Doubler looks for used memory blocks that the computer is not likely to access. These blocks are then compressed to save space. This process causes a slight performance hit but is still better than involving the hard drive. On machines with less than 32MB of installed RAM, the time to compress causes a more significant performance hit, hence the 32MB minimum requirement.
• Swapping - As a last resort, RAM Doubler will swap the compressed data from the step above out to the hard drive.

After installing RAM Doubler and rebooting, I promptly opened a variety of RAM hungry applications, Netscape, Dreamweaver, Photoshop to name a few. They all opened quickly without a noticeable lag. A quick trip to RAM Doubler's control panel (pictured below) revealed that it had reclaimed close to 62MB of RAM. I used a wide variety of programs with RAM Doubler running and didn't experience any stability problems whatsoever. Apple's virtual memory scheme consumes drive space equal to the amount of virtual memory used + 1MB. In my case, this meant losing 129MB of drive space. If you want to use virtual memory's upper limit of 1GB, be prepared to kiss a major chunk of your drive space good-bye. RAM Doubler operates without this requirement, only using the hard drive if reallocation and compression are insufficient.

Caveats: The first, and perhaps most important thing to be aware of is that even with RAM Doubler installed, you should not set applications' memory allocations beyond the amount of physical RAM present. In other words, if you have 32MB RAM installed in your machine, you should not allocate 40MB to Photoshop or other applications. Doing so can cause performance slowdowns and instability. To find a safe maximum for allocation, subtract the RAM used by the system from the amount of physically installed RAM. If you make use of a RAM disk (to store a web browser's cached pages for example) this memory is not available to be extended by RAM Doubler. Lastly, if you are working with audio or video software, remember that you are still using virtual memory. Some of these programs may perform poorly or refuse to run until you reboot with RAM Doubler disabled.

Conclusions: RAM Doubler is a one trick pony but fortunately it does that one trick very well. Thanks to its three tiered approach to extending memory most users shouldn't notice a performance hit. RAM prices seem to fluctuate more than the stock market but RAM for older machines is notoriously expensive. At roughly $50, RAM Doubler is a cheap way to give your applications a little breathing room. RAM Doubler's 240MB upper limit reduces its value somewhat for machines with more than 80MB installed RAM, but even with my 128MB I would consider this a worthwhile purchase.

Product: RAM Doubler 9
Company: Connectix
Hits: Well designed and informative interface, excellent printed documentation, only uses drive space as a last resort, free update for RAM Doubler 8 owners.
Misses: 240MB limit, some compatibility issues with older hardware.
Rating: (5 possible)
Requirements: - Power PC, G3 or G4 processor - OS 8 or newer, OS 9 supported - 32MB physical RAM	Compatibility issues: - Apple Geoport Telecom Adapter & Geoport Internal Modem - Some older video cards may not be compatible or may need a ROM update to work. - NuBus SCSI-2 boards