From mboxrd@z Thu Jan 1 00:00:00 1970 From: Todd Strader Subject: Multicast Scaling Date: Thu, 05 Aug 2010 14:34:34 -0500 Message-ID: <4C5B124A.7030409@exegy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org Hi, I'm running ib_send_bw (version 1.20) over ConnectX HCAs on an Infiniscale III switch. If I run: ib_send_bw -s 256 -c RC I get 790 MB/s ib_send_bw -s 256 -c UD still gets me 790 MB/s ib_send_bw -s 256 -c UD -g 1 which runs over a multicast GID/LID gets 790 MB/s when there are two HCAs on the switch. However: 3 HCAs - 726 MB/s 4 HCAs - 701 MB/s . . . 12 HCAs - 205 MB/s I'm trying to understand why this drops off for each new HCA I add to the switch. All the HCAs and the switch are running the latest firmware (2.7.0 and 1.0.5 respectively). Only one HCA is transmitting and only one is receiving. All the other HCAs are quiet. I'm wondering if anyone has any suggestions on what causes this effect and how I might deal with it. Thanks. Todd ********************************************************************************************** This e-mail and any documents accompanying it may contain legally privileged and/or confidential information belonging to Exegy, Inc. Such information may be protected from disclosure by law. The information is intended for use by only the addressee. If you are not the intended recipient, you are hereby notified that any disclosure or use of the information is strictly prohibited. If you have received this e-mail in error, please immediately contact the sender by e-mail or phone regarding instructions for return or destruction and do not use or disclose the content to others. ********************************************************************************************** -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html