Remember SoftRAM 95? Compression app claimed to double memory in Windows but actually did nothing at all

Microsoft's Raymond Chen was tasked with digging into the issue

One of the most consistently interesting and entertaining Microsoft blogs, Raymond Chen's Old New Thing, recently covered the dissection of a best-selling bit of software for Windows 95 – SoftRAM 95. There are few lessons about modern software in there as well.

What SoftRAM 95 claimed to do was software memory compression – on-the-fly compressing data in RAM so that your OS has more fast storage available than without the software. This crazy-sounding idea first appeared with Connectix's RAMdoubler in 1994, back when Mac OS 7.1 was current (although it worked on System 6, too). It was a slightly easier proposition on classic MacOS, due to its very basic, semi-manual memory management. Doubling your system's RAM sounded like a great deal in 1994, when a 4MB SIMM would cost $170 – £230 today.

Memory compression works by introducing a second level of swapping to the OS. OSes that support virtual memory have a two-way split, between real physical RAM and virtual memory in a file on disk. Memory compression introduces a layer in between these: it partitions off a block of system memory for compression. When the OS runs low on RAM and swaps something out to disk, the memory compressor intercepts this, compresses the contents using a fast algorithm, but keeps it in RAM. It's fairly likely that the data will be needed again soon, and if so, the memory compressor decompresses it and puts it back in main memory. This operation is considerably faster than retrieving it from the hard drive – in computer terms, it's days versus weeks.

RAM compression is still very much a thing today. The feature is built into Windows 10 and has been in macOS since 10.9. Linux has not one but two comparable features, but they're optional.

Back in the '90s, this was state-of-the-art stuff. Mark Russinovich, then of Winternals but now a Microsoftie himself, analysed SoftRAM 95, wrote a tool to test the functionality, and declared that it didn't work. (We've linked to all three pages as after quarter of a century, the page-number buttons no longer work.) Interestingly, two of its rivals did work, although people's enthusiasm very quickly wore off.

SoftRAM did have some marginally useful functionality on Windows 3.1, achievable for free anyway by tweaking some config files, but on Windows 95 it didn't do anything at all. This caused a minor scandal at the time – even renowned tech journal the Christian Science Monitor mentioned it.

In case you think that such things couldn't happen today, they do. Antivirus apps for iOS were for a time an example, even though iOS sandboxes apps – so an app literally cannot scan your phone.

One of the common ones today are "registry cleaners". Windows' registry doesn't need cleaning, and by removing entries, these can harm your PC. Want a cleaner PC? Run the built-in Disk Cleanup tool. Tick all the boxes and click OK. Then do it again and press the "Clean up system files" button. Reboot, and the job's a good one. ®