pci is 32-bits wide?

[nmaster]

I guess when it comes to my laptop I don't usually care much about my hardware unless I have a problem, but I was just looking at 'lshw' and noticed the following:



*-pci
description: Host bridge
product: Mobile PM965/GM965/GL960 Memory Controller Hub
vendor: Intel Corporation
physical id: 100
bus info: pci@0000:00:00.0
version: 03
width: 32 bits
clock: 33MHz
configuration: driver=agpgart-intel module=intel_agp


A lot of my hardware seems to have a width of 32-bits even though I have a 64-bit processor... Could someone explain this to me?

[nmaster]

bump. anyone offer an explanation?

[tgalati4]

Legacy support. ISA busses are 8 and 16 bit wide. You would need to upgrade your motherboard to get 64-bit expansion slots.

Your machine probably has 64 bit data paths between RAM and the CPU. If not, then it takes 2 clock cycles to load each 64-bit word into the CPU.

Because of the long history of intel and the x86 architecture, you will see a lot of performance compromises to maintain compatibility. Hence your 32-bit motherboard can interface with a 64-bit processor.

[nmaster]

thanks for the info.