Hi Timo,

As a general rule, never use any performance number from atomic mode.
Atomic mode is for fast forwarding and warming (and for anything
non-temporal). The only notion of time is ‘enough to not confuse the OS’.

I would recommend to re-run your experiment with a realistic timing core
model (e.g. minor or arm_detailed), and a realistic DRAM controller (e.g.
DDR3_1600_x64).

I hope that explains it.

Andreas

On 16/07/2015 21:26, "gem5-users on behalf of Timo Schneider"
<[email protected] on behalf of [email protected]> wrote:

>Hi!
>
>I am running the stream benchmark[1] in GEM5 in SE, like this
>
>./build/X86/gem5.opt --debug-flags=ExecTicks ./configs/example/se.py
>--mem-type=SimpleMemory -n 1 -c /gem5tests/stream
>
>The bandwidth reported is 2000 MB/s. Now if I run it on two CPUs in
>parallel, like this
>
>./build/X86/gem5.opt --debug-flags=ExecTicks ./configs/example/se.py
>--mem-type=SimpleMemory -n 2 -c /gem5tests/stream;/gem5tests/stream
>
>the reported bandwidth is still ~2000 MB/s, reported by both processes!
>I expected it to be in the order of 1000 MB. The same happens with
>different memory types, etc.
>
>Can someone explain why the memory bandwidth is not halved?
>
>Thank you!
>
>
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