Re: process max virtual memory limit in amd64?

[Alexander Rapp <alexander@alexander.co.tz>]

Anders Fugmann wrote:
> Does anyone know why there is a limitation of 48 bits on the virtual 
> address space, and if it is technically possible to have a 64 bit 
> address space on the AMD64 architecture?

I was under the impression that memory addressing was limited to 48bits 
on today's amd64s to increase efficiency/performance.  Longer addresses 
take up more space in cache and more bandwidth on the bus.  By 
decreasing the size of every single memory request by 16 bits, more 
instructions can be fit in cache and more can be transmitted in a given 
time.  When allocations of over 256TB become necessary, the architecture 
is designed to support longer addresses as well.

-- Alexander Rapp