Are Intel CPUs better than AMD CPUs for DPDK applications?

Are Intel CPUs better than AMD CPUs for DPDK applications?

[Staffan Wiklund]

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Hello

Do you know if there is a difference in support for DPDK that is provided by
Intel and AMD CPUs respectively?

I talked to a person today claiming he has learned that Intel CPUs have
been preferred over AMD CPUs for some DPDK applications.
This person had no document showing reasons for this.

Do you have any information on this?
If there is a difference, will the difference be negligible do you think
from a
technical perspective?

Regards
Staffan

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Re: Are Intel CPUs better than AMD CPUs for DPDK applications?

[Stephen Hemminger]

On Mon, 21 Feb 2022 16:14:26 +0100
Staffan Wiklund <staffan491@gmail.com> wrote:

> Hello
> 
> Do you know if there is a difference in support for DPDK that is provided by
> Intel and AMD CPUs respectively?
> 
> I talked to a person today claiming he has learned that Intel CPUs have
> been preferred over AMD CPUs for some DPDK applications.
> This person had no document showing reasons for this.
> 
> Do you have any information on this?
> If there is a difference, will the difference be negligible do you think
> from a
> technical perspective?
> 
> Regards
> Staffan

There is no one Intel CPU and one AMD CPU. There are lots of types so the
statement is very vague and misleading. 

Re: Are Intel CPUs better than AMD CPUs for DPDK applications?

[Staffan Wiklund]

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Stephen, thanks for your answer.
I realize the statement is very vague.
I was thinking of if there was something common in the design of Intel and
AMD CPUs respectively that has an impact on their use by DPDK applications.
Do you know if there is such a common design difference between Intel and
AMD CPUs or is it just a matter of using an Intel or AMD CPU with the
requested performance?

Regards
Staffan

Den mån 21 feb. 2022 kl 18:08 skrev Stephen Hemminger <
stephen@networkplumber.org>:

> On Mon, 21 Feb 2022 16:14:26 +0100
> Staffan Wiklund <staffan491@gmail.com> wrote:
>
> > Hello
> >
> > Do you know if there is a difference in support for DPDK that is
> provided by
> > Intel and AMD CPUs respectively?
> >
> > I talked to a person today claiming he has learned that Intel CPUs have
> > been preferred over AMD CPUs for some DPDK applications.
> > This person had no document showing reasons for this.
> >
> > Do you have any information on this?
> > If there is a difference, will the difference be negligible do you think
> > from a
> > technical perspective?
> >
> > Regards
> > Staffan
>
> There is no one Intel CPU and one AMD CPU. There are lots of types so the
> statement is very vague and misleading.
>

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Re: Are Intel CPUs better than AMD CPUs for DPDK applications?

[Stephen Hemminger]

On Mon, 21 Feb 2022 21:28:08 +0100
Staffan Wiklund <staffan491@gmail.com> wrote:

> Stephen, thanks for your answer.
> I realize the statement is very vague.
> I was thinking of if there was something common in the design of Intel and
> AMD CPUs respectively that has an impact on their use by DPDK applications.
> Do you know if there is such a common design difference between Intel and
> AMD CPUs or is it just a matter of using an Intel or AMD CPU with the
> requested performance?
> 
> Regards
> Staffan

I am not a CPU expert. But compare memory bandwidth, clock rate, PCI Express version
and support for AVX support (for some features). There a few places in DPDK
that can use AVX512 but it is limited 
https://doc.dpdk.org/guides/howto/avx512.html

Also there is a tradeoff with more cores, NUMA, etc as well as cost.

Don't believe simple tribal knowledge, you need to look under the covers.

Re: Are Intel CPUs better than AMD CPUs for DPDK applications?

[Staffan Wiklund]

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Thanks Stephen again for your help.
I will check out what you mentioned about CPU features.

By the way, regarding my earlier question about using DPDK memif in a
Docker container.
I made a patch in the memif driver of DPDK so it uses a TCP socket instead
of a UNIX domain socket.
This made it possible to communicate between a Docker container and an
application outside the container using DPDK memif.
This patch only works without the "zero-copy" option for DPDK memif.
But the throughput of DPDK memif without zero-copy is rather good anyway.

Regards
Staffan


Den tis 22 feb. 2022 kl 02:49 skrev Stephen Hemminger <
stephen@networkplumber.org>:

> On Mon, 21 Feb 2022 21:28:08 +0100
> Staffan Wiklund <staffan491@gmail.com> wrote:
>
> > Stephen, thanks for your answer.
> > I realize the statement is very vague.
> > I was thinking of if there was something common in the design of Intel
> and
> > AMD CPUs respectively that has an impact on their use by DPDK
> applications.
> > Do you know if there is such a common design difference between Intel and
> > AMD CPUs or is it just a matter of using an Intel or AMD CPU with the
> > requested performance?
> >
> > Regards
> > Staffan
>
> I am not a CPU expert. But compare memory bandwidth, clock rate, PCI
> Express version
> and support for AVX support (for some features). There a few places in DPDK
> that can use AVX512 but it is limited
> https://doc.dpdk.org/guides/howto/avx512.html
>
> Also there is a tradeoff with more cores, NUMA, etc as well as cost.
>
> Don't believe simple tribal knowledge, you need to look under the covers.
>

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