64bits linux vs. 32bits linux: access to PCIe

Hello,

From what I know, access to DDR is faster with 64bits linux O.S compared to 32bits linux O.S

Is this true also for PCIe memory mapped registers ?

Thank you,
Z.V

If by DDR you mean DRAM I don't know that there is any difference since memory access is by cache line, not register word size. Where are you getting that information and for what processor?

It may be possible that a more new compiled driver for some onboard chipset could run slightly faster under 64 but you'd need a server farm running non-stop for year or two to measure it. In the most general terms the load on a task is the end result of many processes. That could be more easily seen in some cases using 64 bit. The actual clock timings of data should not change for dram or pci access in any case.

Hello,

I wonder: What is the added value of a 64bit O.S vs. 32bit O.S ?
64bit O.S can work with DRAM > 4GB.
Any other advantages ?

Best regards,
Z.V

Hello,

I'm using kernel 4.1.13 from kernel.org
I have to compile it for ARM-V7 (LS1021A-TWR).

Is there an official patch source in kernel.org ?

Thank you,
Z.V