This is my source for those theoretical numbers:
http://dewaele.org/~robbe/thesis/writing/references/49747D_HPC_Processor_Comparison_v3_July2012.pdf
If those numbers are off, that makes my job a bit easier. And it looks
like you're right. In the text above the table, it does mention 2-socket
servers, and then below the table in fine print, it states
"For AMD Opteron Processors, theoretical FLOPS = Core Count x Core
Frequency x number of processors per server x 4."
Why can't the table just show single socket performance? Grrrr....
Regardless of bad marketing and graphics design, I'm still at at square
one. My system has 2 sockets, and the best I've been able to do is get
~115 GFLOPS. And that's one of the 'instaneous' values LINPACK spits out
every few seconds. At the end of test, the actual GFLOPS result is more
like 77 GLOPS:
===========================================
T/V N NB P Q Time Gflops
--------------------------------------------------------------------------------
WR00L2L2 82775 40 4 8 4924.71 7.678e+01
This is a two socket system, so that's only 27% of theoretical max.
Prentice
On 02/22/2018 01:18 PM, Dmitri Chubarov wrote:
Hi,
not sure if the 282 GFLOPS number is correct.
We have 16 Bulldozer/Interlagos cores at 2.2 GHz. Each pair of cores
forms a CMT module. The two cores in the module share an FPU with 2
128-bit FMAC units.
In terms of double precision FLOPS it should make
16 * 2.2GHz * 2 double precision scalars/SIMD register * 2 FLOPS / FMA
op = 140.8 GFLOPS
It looks like 282 GFLOPS number is per a 2P node.
Dima
On 22 February 2018 at 21:37, Prentice Bisbal <pbis...@pppl.gov
<mailto:pbis...@pppl.gov>> wrote:
Beowulfers,
In your experience, how close does actual performance of your
processors match up to their theoretical performance? I'm
investigating a performances issue on some of my nodes. These are
older systems using AMD Opteron 6274 processors. I found
literature from AMD stating the theoretical performance of these
processors is 282 GFLOPS, and my LINPACK performance isn't coming
close to that (I get approximately ~33% of that). The number I
often hear mentioned is actual performance should be ~85%. of
theoretical performance is that a realistic number your experience?
I don't want this to be a discussion of what could be wrong at
this point, we will get to that in future posts, I assure you!
--
Prentice
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