From owner-freebsd-hackers Fri Sep 1 00:06:48 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id AAA19465 for hackers-outgoing; Fri, 1 Sep 1995 00:06:48 -0700 Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.34]) by freefall.FreeBSD.org (8.6.11/8.6.6) with ESMTP id AAA19457 for ; Fri, 1 Sep 1995 00:06:38 -0700 Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.9/8.6.9) id RAA31341; Fri, 1 Sep 1995 17:01:07 +1000 Date: Fri, 1 Sep 1995 17:01:07 +1000 From: Bruce Evans Message-Id: <199509010701.RAA31341@godzilla.zeta.org.au> To: davidg@Root.COM, pst@shockwave.com Subject: Re: novell ne2000 cards with FreeBSD...opinions? Cc: hackers@freebsd.org Sender: hackers-owner@freebsd.org Precedence: bulk >>What kind of performance can I expect to see on a NE2000 vs a 16 bit SMC card >>when running FreeBSD? >> >>e.g. would you dare build a diskless NFS client with a NE2000 clone? > It will require twice the CPU, and in some extreme cases, this might be >enough to cause it to drop a packet. ...but normally it will work fine. I.e., it would require about 100% of the cpu instead of only about 50%. This is very dependent on the number of wait states for the ISA bus. I use NE2000/WD8013EBT clones in WD mode and see the following overheads: 486DX2/66 ttcp -t: 21% Sys 51% Intr 486DX /33 ttcp -t: 29% Sys 51% Intr 486DX2/66 ttcp -r: 17% Sys 52% Intr 1094.78 KB/sec 486DX /33 ttcp -r: 22% Sys 58% Intr 1098.10 KB/sec In NE2000 mode the interrupt overhead goes up enough for at least the DX/33 to run out of cycles - 100% of the cpu is used and the speed drops to about 1000 KB/sec. Bruce