Re: I/OAT ... Coming Soon ?

Doug Ambrisko wrote:
> Julian Elischer writes:
> | Jack Vogel wrote:
> | > On Nov 14, 2007 5:01 PM, Wilkinson, Alex
> | > <Alex.Wilkinson_at_dsto.defence.gov.au> wrote:
> | >> Hi all,
> | >>
> | >> Curious, is I/OAT [http://www.intel.com/go/ioat/] coming to FreeBSD soon
> | >> ?
> | > 
> | > LOL, I did a driver for the first version of I/OAT more than a year
> | > ago, submitted
> | > it and interest was half hearted.
> | > 
> | > The driver needs updating and polishing yet, but interest being what it was
> | > it hasn't been a real high priority.
> | 
> | I saw what I thought you called a "preliminary" driver.
> | There was discussion and I thought you got positive but 
> | muted (along the lines of "nice.. when will there be hardware for it?")
> | and some discussion of how it fits in with TCP offload, but I don't think
> | that anyone said they didn't like the idea..
> 
> FWIW, several of us should have motherboards that support it now.
> For example the Dell PE29XX/PE1950 line now has support if you upgrade
> old machines to a newer BIOS and then turn it on in the BIOS setup.  
> I'm not sure what em(4) cards support it.  So I think hardware should 
> be available now.  At the time the PE29XX family BIOS did not support it :-(

I/OAT is a chipset, or rather memory controller, feature currently only
supported in Intel chipsets.  If AMD were to support it as well it
would have to reside on the CPU die as it is integrates the memory
controller.

Simply put I/OAT is nothing more than a hardware offloaded bcopy()
working on physical addresses.  The idea is to free the CPU bandwidth
from performing the bcopy itself.

-- 
Andre