Upgrading a PIX 506E past 32MB

As all PIXes are essentially Intel x86 boxes (501 is AMD), the RAM controller will recognize and PIX OS will use the additional memory. However, in reality You'll first hit performance limitations before You hit the memory limitations.

AFAIR PIXes use simple DIMMs. My home PIX 515 has 256MB of RAM and it's happy with it for already about two years.

Correct! I upgraded two 506e's to 64MB using some otherwise useless PC-100

32MB sticks of RAM. The 506e's have two RAM slots.

Since we are on the topic of unsupported 506e configurations, I loaded

7.0(6) onto the 506e's with 64MB of RAM (7.x will not boot with 32MB of RAM). The 7.0(6) image will fit if no PDM image is loaded on the flash also. I had a situation where two remote servers (highly critical, low bandwidth) performing a specific function benefited from having a transparent firewall placed between them and the rest of the network. Saved the company a few bucks in material cost. 7.0(6) is the last image that will fit on the 506e's flash (but you must be willing to live without a GUI). I can't upgrade the 506e's any further, but in theis situation it's a non-issue.