Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 5 Oct 2001 02:53:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 5 Oct 2001 02:53:21 -0400 Received: from wolf.ericsson.net.nz ([203.97.68.250]:61852 "EHLO wolf.ericsson.net.nz") by vger.kernel.org with ESMTP id ; Fri, 5 Oct 2001 02:53:12 -0400 Date: Fri, 5 Oct 2001 18:53:35 +1200 (NZST) From: Mark Henson To: Ben Greear cc: Subject: Re: Throughput @100Mbs on link of ~10ms latency In-Reply-To: <3BBD4D54.96A08A3D@candelatech.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 4 Oct 2001, Ben Greear wrote: > printAndExec("echo $rmem_default > /proc/sys/net/core/rmem_default"); > printAndExec("echo $netdev_max_backlog > /proc/sys/net/core/netdev_max_backlog"); > ... thanks - tried these parameters and saw no change in the throughput. I am thinking that the problem is at the receiving end rather than the transmit end because with the FreeBSD machine at 1 end I got a much higher throughput when sending to that machine. (about 10 MBytes /sec) I was suspicious of another problem with the FreeBSD machine which is why I changed it out. (network occasionally locked up). The distance between the local ethernet switches is about 1200km of fibre. Speed of light for that distance is ~ 4ms. Light in fibre I believe to be about 0.6 giving around 6.5ms for light in this loop - so 9.5 ms RTT seems pretty good The machines (Compaq Deskpro ~800MHz) are able to reliably produce ~10MBytes/sec using ncftp which is hardly calibrated but is atleast indicative of the rate I should be getting. Calculating transfer time of 26/27 secs of 106348240 gives me net of about 32Mbps anyway thanks for your help cheers Mark one machine is: eth1 Link encap:Ethernet HWaddr 00:04:76:B8:8B:DC inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:11757991 errors:0 dropped:0 overruns:1 frame:0 TX packets:11699364 errors:0 dropped:0 overruns:0 carrier:49 collisions:274 txqueuelen:100 Interrupt:5 Base address:0x1000 eth1: 3Com PCI 3cSOHO100-TX Hurricane at 0x1000, 00:04:76:b8:8b:dc, IRQ 5 product code 4d4d rev 00.12 date 06-29-01 8K byte-wide RAM 5:3 Rx:Tx split, autoselect/Autonegotiate interface. MII transceiver found at address 24, status 7849. Enabling bus-master transmits and whole-frame receives. eth1: scatter/gather disabled. h/w checksums enabled eth1: using NWAY device table, not 8 the second is: eth1 Link encap:Ethernet HWaddr 00:01:03:39:ED:5F inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:9567005 errors:0 dropped:0 overruns:0 frame:0 TX packets:9652682 errors:0 dropped:0 overruns:0 carrier:607 collisions:0 txqueuelen:100 Interrupt:5 Base address:0x1000 eth1: 3Com PCI 3c980 10/100 Base-TX NIC(Python-T) at 0x1000, 00:01:03:39:ed:5f, IRQ 5 product code 4b50 rev 00.14 date 03-12-01 8K byte-wide RAM 5:3 Rx:Tx split, autoselect/Autonegotiate interface. MII transceiver found at address 24, status 7809. Enabling bus-master transmits and whole-frame receives. > > And of course, make sure you can get the performance with a known fast network > (and near zero latency) first!! > > The e100 has some interesting options that seem to make it handle high packet > counts better, as well as giving it bigger descriptor lists, but I haven't > really benchmarked it.. > > Ben > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/