RE: AMD vs Intel
I did a similar comparison man years ago (circa 2010) while chasing down a
1-bit difference in an Intel vs AMD floating point result. There is (or at
least was) a slight difference in the 80 bit floating point hardware (Intel
and AMD both use an 80 bit registers internal) and even found a reference
somewhere in either an Intel or AMD document (sorry, no longer have it) that
can give rise to this. Apparently there is a compiler switch that can be used
to turn off
The internal 80-bit computation - see
https://stackoverflow.com/questions/612507/what-are-the-applications-benefits-of-an-80-bit-extended-precision-data-type
and answer therein that refer to this compiler option.
Quoted reply history
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
Leonid Gibiansky
Sent: Monday, November 18, 2019 12:05 PM
To: nmusers <[email protected]>
Subject: [NMusers] AMD vs Intel
Dear All,
I am testing the new Epyc processors from AMD (comparing with Intel Xeon), and
getting different results. Just wondering whether anybody faced the problem of
differences between AMD and Intel processors and knows how to solve it. I am
using Intel compiler but ready to switch to gfortran or anything else if this
would help to get identical results.
There were reports of Intel slowing the AMD execution in the past, but in my
tests, speed is comparable but the results differ.
Thanks
Leonid