Dual Core Xeon / i386 install w/ more than 4gb of RAM

[Ivan Voras]

Tom Samplonius wrote:

>   Is PAE really that stable?  I thought it was fairly unpolished, mainly because PAE is seen as a weak kludge implemented by Intel because they all thought we would all be using Itanium's by now.  Intel reversed their folly pretty quickly, adopted the x86-64 extensions as-is from AMD, and pushed them onto every piece of silicon they make.

Architecturally, it's a nasty kludge. As far as stability on FreeBSD is
concerned, my only machine under PAE with 4 GB RAM (without PAE it would
use a bit over 3 GB) is very solid on 6-STABLE.

>   I also really don't know how anyone would properly use 16GB of RAM under PAE anyways?  Each process is going to limited to just under 4GB.  The kernel memory space can't be bigger than 4GB either, so forget about a huge disk cache.

As I understand it, one possible benefit could be to use the memory for
disk / file cache. AFAIK the pages are just pages, without distinction
where they are mapped, and for example, if you run PostgreSQL, it
couldn't use more than 4 GB for its own data (actually closer to 2 GB
because of some sysvshm issues) but it will indirectly use the cache.

>   And is there some really stability fear about FreeBSD on x86-64?  Seems just the same as i386.

I agree, FreeBSD on amd64 is very stable.

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