From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id BABBEA0503 for ; Wed, 18 May 2022 18:40:50 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 8684C40156; Wed, 18 May 2022 18:40:50 +0200 (CEST) Received: from mail-oa1-f54.google.com (mail-oa1-f54.google.com [209.85.160.54]) by mails.dpdk.org (Postfix) with ESMTP id 0B3A7400D6 for ; Wed, 18 May 2022 18:40:49 +0200 (CEST) Received: by mail-oa1-f54.google.com with SMTP id 586e51a60fabf-f16a3e0529so3456729fac.2 for ; Wed, 18 May 2022 09:40:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:from:date:message-id:subject:to; bh=DVKXOZuv2GpGpbNBmQ8DwxaVc7qbgcZD86qGTdXiWTk=; b=leiVAA2JlB4mBFgSUj42A7DBSVFJhG4UE4caDmn6XUVjbRc/Z+5GsxLxxDbVAUIUhc kqhANSwf1+wj1DOWVBbsH6NTM4h2MPi2UsyFnRvbZeAGbpO2ICMLSix1gHiNxKkLwrke k9YbcvueEOWQ2lG6DB67t6qLMDZGAVv2y+kv5R6TjNgH7kC9ISnJnfbBLrIh3heRBz7O 7V9kYNO4RJpNIVcw0UbuVP1MPrj8HfWRWjhcViSKZ45h3HjXYao5+4WcTj6znRGyZ/9u uI9IIVa/6/8melAzs09qHZz3eFH4At856ukjodIDr+314MOWt4jREOCm9AsCUb1bbvsJ EH1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=DVKXOZuv2GpGpbNBmQ8DwxaVc7qbgcZD86qGTdXiWTk=; b=RWsnhsdhV53mrd2/aeknZGFp1O+Ge/jSnpgeuLbsxlyIcAWS/unHN2kaEK9ZH0huMh jkejwbXBnOUYYQ4HQMI8yXwfAdIt1xid9h3ibNp1ObAyAManNnAC7sb8xeu/yh5foWg/ mA83sdWzQeWrNU61Uw+uGmphqsc4jdAkiV/k81j1EGbqyNyRxk2jNkAmEKa+s/nJjQx8 qIq/UaQtLPFVTzOS2XZWoOEP4+MRN3/URdg3q7tt9+o0bTNA7MQP4Dv9tzFUGJGvqoTu 3vgRKf3/jvJ5HbIhc3kAPBwYJ2QXpQRu84faTwL/bBSpSJeBwPO0Dsk1z7ojk9Dj0C+8 kKzA== X-Gm-Message-State: AOAM53220GN/JmTrd6TLrGFFtTPnCleFAFiIspt7f8wDPjlm/bR64n1/ l045MYgNnn+Qh+wes5LE/ZAk7Z01OcjERY9xJuJty6dxlzyDZg== X-Google-Smtp-Source: ABdhPJwJabtWwp92fYsN+VQGk9dN227CLxfXN13ymrjl9Jp4W03ICGI4q31kjIIXrhXp1J+UeAu1vcYD17MYhwHaXbA= X-Received: by 2002:a05:6870:b686:b0:dc:a9f4:90a2 with SMTP id cy6-20020a056870b68600b000dca9f490a2mr541408oab.243.1652892048084; Wed, 18 May 2022 09:40:48 -0700 (PDT) MIME-Version: 1.0 From: Antonio Di Bacco Date: Wed, 18 May 2022 18:40:37 +0200 Message-ID: Subject: DPDK performances surprise To: users@dpdk.org Content-Type: multipart/alternative; boundary="00000000000060d30005df4beb57" X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org --00000000000060d30005df4beb57 Content-Type: text/plain; charset="UTF-8" I recently read a performance test where l2fwd was able to receive packets (8000B) from a 100 Gbps card, swap the L2 addresses and send them back to the same port to be received by an ethernet analyzer. The throughput achieved was close to 100 Gbps on a XEON machine (Intel(R) Xeon(R) Platinum 8176 CPU @ 2.10GHz) . This is the same processor I have and I know that, if I try to write around 8000B to the attached DDR4 (2666MT/s) on an allocated 1GB hugepage, I get a maximum throughput of around 20GB/s. Now, a 100 Gbps can generate a flow of around 12 GB/s, these packets have to be written to the DDR and then read back to swap L2 addresses and this leads to a cumulative bandwidth on the DDR that is around 2x12 GB/s and is more than the 20GB/s of available bandwidth on the DDR4. How can this be possible ? --00000000000060d30005df4beb57 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I recently read a performance test where l2fwd was able to= receive=C2=A0packets (8000B) from a 100 Gbps card, swap the L2 addresses a= nd send them back to the same port to be received by an ethernet analyzer. = The throughput achieved was close to 100 Gbps on a XEON machine (Intel(R) X= eon(R) Platinum 8176 CPU @ 2.10GHz) . This is the same processor I have and= I know that, if I try to write around 8000B to the attached DDR4 (2666MT/s= ) on an allocated 1GB hugepage, I get a maximum throughput of around 20GB/s= .=C2=A0

Now, a 100 Gbps can generate a flow of around 12= GB/s, these packets have to be written to the DDR and then read back to sw= ap L2 addresses and this leads to a cumulative bandwidth on the DDR that is= around 2x12 GB/s and is more than the 20GB/s of available bandwidth on the= DDR4.=C2=A0

How can this be possible ?=C2=A0
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