[Beowulf] 64 bit Xeons?

Greg Lindahl lindahl at pathscale.com
Wed Jan 19 23:01:21 PST 2005

On Thu, Jan 20, 2005 at 02:54:14PM +1100, Chris Samuel wrote:
> On Tue, 18 Jan 2005 03:47 am, Craig Tierney wrote:
> > It uses the 64-bit extensions that AMD uses for the Opteron.
> I believe that Intel tinkered with a couple of the instructions of the 
> original AMD instruction set, so whilst it's almost identical it's not quite.
> The major one that I'm aware of is that although it reports it supports an 
> address size of 40 bits it can only handle 36 bits of physical memory.

... which is because Intel copied it too closely, not because Intel
tinkered with it.

-- greg

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