amd64 slower than i386 on identical AMD 64 system?

[Claus Guttesen]

> SMP with single dual-core processors are randomly crashing when >2GB and <4GB
> on standard MBs
>  ...
> I understand here that amd64 is still not dealing well with dual-cores and
> more than 2GB of RAM

I have two web-servers with 4 GB RAM, one with 4 single-core opterons,
the other with 2 dual-core. I have one db-server with 8 GB RAM with 2
dual-core, all working flawlessly. I have two web-servers with 4 GB
RAM and 2 single-core opterons.

I had problems related to RAM becoming corrupt with the server having
8 GB, swapping 4 GB of the exact same type of RAM-modules from another
server cured the server. The server that got the RAM-modules did not
excibit abnormal behaviour, ran it for hours with memtest
(www.memtest.org) without problems. So it very much depends on your
motherboard and type of ram etc.

Other than I don't recall I had any serious issues in that area except
for ata-drivers not being 4 GB clean. I even have some Dell dual
xeon's running amd64 and 4 GB RAM :-)

regards
Claus