RAM for digital server 5300

[Simon Tierney]

I have one of these machines which has cards to take PC100 ECC SDRAM
modules, 1 card for each CPU.

The Service and User manuals require replacement RAM  modules of 128 Mb and
256 Mb (in pairs), but larger modules (512Mb) have become available since
these manuals were written.

Has anyone any experience adding these larger modules?  Will the system be
able to address them, or should I stick to 256 modules?