What is Connectix RAM Doubler 1.x?

There's an old saw, “never too rich or too thin.” And one might add, “never enough RAM.” A simple System extension that promises to double your RAM for less than $100 sounds too good to be true, right? Well, RAM Doubler from Connectix does just that for many Macintosh users.

Inevitably, there are restrictions. RAM Doubler requires a memory-management unit (MMU), so you must have at least a 68030 Mac, or a 68020 that’s been upgraded with a 68030 accelerator, a 68040 accelerator, or a 68851 PMMU. RAM Doubler’s magic also requires System 7 and 4MB or more of physical RAM. Owners of older Macs and those with less than 4MB of RAM may want to consider OptiMem from Jump Development Group...

In addition, the applications run must be 32-bit clean; RAM Doubler does not work properly in 24-bit addressing mode. And don’t expect to dedicate all of this newfound RAM capacity to a single memory-hungry application such as Adobe Photoshop, Adobe Premiere, or a 3-D rendering program. You can’t allot more memory to any single application than is available as physical RAM. (Connectix recommends leaving applications at their suggested memory settings.) You can’t employ additional memory-management schemes such as Apple’s virtual memory or Connectix’s Virtual. Finally, RAM Doubler doesn’t work with more than 128MB of physical RAM. All this said, RAM Doubler does effectively double the available RAM for the many Macintosh users who fit the program’s profile.

Using RAM Doubler couldn’t be easier. The modest 45K program sports the ultimate interface: none — no control panel or menus. You simply open twice the number of applications without incurring the dread “out of memory” message.

You pay a small price in overall speed. Booting my 8MB Mac IIci with RAM Doubler installed takes about 5 percent (6 seconds) longer than usual. Most normal operations take a second or two longer, but if I run a suite of applications that uses more than 14MB, some operations — such as copying and pasting a large file — take up to 10 percent longer. For me, it’s worth waiting those extra seconds.

To accomplish its digital trick, RAM Doubler relies on several techniques. The most important involves a dynamic mapping of the RAM allocated to individual applications. An application allotted 4MB, say, is often using only half that amount. RAM Doubler takes charge of the unused memory and applies it where it is currently needed most.

RAM Doubler also compresses routines stored in RAM that are unlikely to be called again — code used to open an application, for instance. Finally, Connectix requires that users with only 4MB to 6MB of physical RAM have a hard disk, because in low-memory situations RAM Doubler may store some low-use routines to the much slower hard disk, a la traditional virtual-memory schemes.

RAM Doubler 1.0 was incompatible with a few applications — chief among them 4D, Frontier, and Now Startup Manager. Patches from the developers of these applications, together with the 1.0.1 version of RAM Doubler, seem to have solved these problems. However, RAM Doubler is still incompatible with the Radius Rocket and Fusion Data Systems’ TokaMac products, since they are not virtual-memory-friendly. To run applications that have a similar distaste for virtual-memory schemes — the popular CD-ROM game Myst, for example — you can disable RAM Doubler when booting by holding down the ~ (tilde) key.

RAM prices may head back down a bit, but meanwhile we’re all still looking for ways to make better use of our current investments in SIMMs. With a street price well below $100 and a 30-day money-back guarantee, RAM Doubler is worth checking out.

Stefanac, Suzanne. (May 1994). RAM Doubler 1.0.1. Macworld. (pg. 65).

Download Connectix RAM Doubler 1.x for Mac

Architecture

Motorola 68K

System Requirements

From Mac OS 6.0

Compatibility notes

Minimum Requirements

• MC68020 processor
• 4 MB RAM
• Hard disk drive
• System 6

Emulating this? It could probably run under: Basilisk II