From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f176.google.com (mail-ig0-f176.google.com [209.85.213.176]) by dpdk.org (Postfix) with ESMTP id 6BD87C536 for ; Mon, 29 Jun 2015 01:46:01 +0200 (CEST) Received: by igrv9 with SMTP id v9so30360871igr.1 for ; Sun, 28 Jun 2015 16:46:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=da8gfdKd6PnbNbMafTCtlv2BbNumxbfrdti7XDN23po=; b=vD20TnTDG4iyV/4S2PuCANqpjgqrTmk1ESoOGZmXpLiFsH6snkbjUT46FOpiqu+rCh i1B10T2YlsaEr6+O33z9Mj3ytK3s38liCDWNr5HCHvn0Pg0gtbLeIzDVTX+Ms85KORSJ IizLRHNLwsbtbessTYC5F5W4Nf7S+i4qPGHWa5UJNyBhCjD7vu9pRmaC2i64FAEqqW+q bsuQjCBQTAsJNgBGnoARBCEGJSNQc/B/kGGdRkM1B2wanIUrDM4Bug/rT47LL6GszArO vkOCPXXnb4iT2XZJCRC+Cn0zjtyty9hRnarfH4P6lgflqCAs4rNdC00Ol9YNCjdsPT30 fEaw== MIME-Version: 1.0 X-Received: by 10.107.10.212 with SMTP id 81mr9696780iok.89.1435535160823; Sun, 28 Jun 2015 16:46:00 -0700 (PDT) Received: by 10.64.156.229 with HTTP; Sun, 28 Jun 2015 16:46:00 -0700 (PDT) In-Reply-To: References: Date: Mon, 29 Jun 2015 05:16:00 +0530 Message-ID: From: Abhishek Verma To: Keunhong Lee Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] Number of memory channels per processor socket? X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Jun 2015 23:46:01 -0000 Thanks Keunhong. How do i get the motherboard spec on a virtual machine thats spawned on the cloud, for example Amazon EC2? Cheers, Abhishek On Mon, Jun 29, 2015 at 4:53 AM, Keunhong Lee wrote: > See your motherboard spec. > For example, I'm using Intel 5930K with ASUS X99 Delux Motherboard (x99 > chipset). > This site https://www.asus.com/us/Motherboards/X99DELUXE/specifications/ > tells that > "Quad Channel Memory Architecture " > which means that "-n 4" is the correct configuration for me. > > To fully use quad channel memory, I have to use 4 separated DRAM, > installed on different memory slots of my motherboard. > > -n option optimizes memory bank access pattern for datastructures. > Since most motherboards support dual or quad memory channel, > -n 4 will work for most systems. (Only few motherboards support > tri-channel memory) > > I hope that this information is useful to you. > Keunhong. > > > > 2015-06-28 18:54 GMT+09:00 Abhishek Verma : > >> Hi, >> >> I am new to DPDK and i tried searching the archives in case this had been >> discussed but couldnt find any references and hence this email: >> >> What is the significance of " -n NUM: Number of memory channels per >> processor socket" which is passed as an EAL option? I have a virtual >> machine (VM) spawned using VirtualBox and i am trying to use DPDK to get >> faster access to packets there. I did lscpu, but that didnt give me >> anything interesting that i could use here: >> >> abhishekV@VirtualBox:~/dpdk/dpdk-2.0.0/x86_64-native-linuxapp-gcc/app$ >> sudo >> lscpu >> [sudo] password for abhishekV: >> >> Architecture: x86_64 >> CPU op-mode(s): 32-bit, 64-bit >> Byte Order: Little Endian >> CPU(s): 2 >> On-line CPU(s) list: 0,1 >> Thread(s) per core: 1 >> Core(s) per socket: 2 >> Socket(s): 1 >> NUMA node(s): 1 >> Vendor ID: GenuineIntel >> CPU family: 6 >> Model: 58 >> Stepping: 9 >> CPU MHz: 2594.017 >> BogoMIPS: 5188.03 >> L1d cache: 32K >> L1d cache: 32K >> L2d cache: 6144K >> NUMA node0 CPU(s): 0,1 >> abhishekV@VirtualBox:~/dpdk/dpdk-2.0.0/x86_64-native-linuxapp-gcc/app$ >> >> I understand that i have two cores and hence should use -c 1 (since i have >> cores 0 and 1). However, i dont understand what to give as the "-n" >> option. >> Is it always 4? >> >> Thanks, Abhishek >> > >