From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Xiaoliang (David) Wei" Subject: Re: gigabit ethernet Date: Thu, 12 Feb 2004 01:34:32 -0800 Sender: netdev-bounce@oss.sgi.com Message-ID: <402B48A8.3060800@caltech.edu> References: <20040212083915.73516.qmail@web21109.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com Return-path: To: satya srikanth In-Reply-To: <20040212083915.73516.qmail@web21109.mail.yahoo.com> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Hi Satya, Did you check the CPU utilization? If you use smaller packet size, the interrupt rate may be a problem. You can modulate the NIC's interrupt rate. See the document for details: http://www.intel.com/support/network/adapter/1000/e1000.htm#parameters Also, I assume the round trip propagation delay for your connections is very small (such as <10ms)? -David satya srikanth wrote: > Sir, > I need some help from you. I am using 2 xeon(2 > GHz) machines each with two processors running linux > 2.4.20-8smp kernel and having intel PRO/1000 gigabit > adapter NIC card(e1000 driver). I tried connecting > both of them using a gigabit switch. I am getting > gigabit speed only if I use my own TCP sockets sending > packets of size around 1400 bytes. If I send packets > of size around 500 bytes, I am getting maximum of only > 500 Mbps. I noticed that NIC is receiving all the > packets but they are getting dropped in the kernel. > I tried changing the settings like > netdev_max_backlog to 30000 and rmem_max, wmem_max and > txqueuelen, but of no use. Can you please suggest some > changes that I need to make to achieve this speed. > (Like changing number of Rx interrupts, Tx interrupts > etc). Can you please suggest some other links where I > can get some useful information. Will linux router > project LRP help me to achieve it. > > with regards, > Satya Srikanth. > -- ------------------------------------------------------ Xiaoliang (David) Wei Graduate Student of CS@Caltech WWW: http://www.cs.caltech.edu/~weixl ======================================================