DD wrote:

Bugs, such as the 64MB problem, aside, increasing RAM always makes your
system faster...* IF *... (nice, big if there) your system is squeezed for
memory.

In the other extreme end, RAM sizes over a certain point requires much more
overhead for the system to use. 4 gig minus memory space used for PCI,
minus any OS peculiarities, exceed that, and you get the glorious overhead
of adressing >4GB on ia32 :)

IIRC, Linux has a 3+1 userspace/kernel split of some sort, and I vaguely
have remember reading an article mentioning that if you already have 3 gig
of RAM, then adding .5 gig would probably be stupid. I don't remember the
exact figures.