Received: (from majordomo@localhost) by oss.sgi.com (8.11.2/8.11.3) id f5G6CJj01485 for netdev-outgoing; Fri, 15 Jun 2001 23:12:19 -0700 Received: from mta2.snfc21.pbi.net (mta2.snfc21.pbi.net [206.13.28.123]) by oss.sgi.com (8.11.2/8.11.3) with SMTP id f5G6CIk01482 for ; Fri, 15 Jun 2001 23:12:18 -0700 Received: from mercury.snydernet.lan ([64.170.211.250]) by mta2.snfc21.pbi.net (Sun Internet Mail Server sims.3.5.2000.01.05.12.18.p9) with SMTP id <0GF0007V0EGHVX@mta2.snfc21.pbi.net> for netdev@oss.sgi.com; Fri, 15 Jun 2001 23:09:53 -0700 (PDT) Date: Fri, 15 Jun 2001 23:09:54 -0700 From: Steve Snyder Subject: Does ISA interrupt latency harm overall system performance? To: netdev@oss.sgi.com Reply-to: swsnyder@home.com Message-id: <01061523095400.01763@mercury.snydernet.lan> MIME-version: 1.0 X-Mailer: KMail [version 1.2] Content-type: text/plain; charset="iso-8859-1" Content-transfer-encoding: 8bit Sender: owner-netdev@oss.sgi.com Precedence: bulk Content-Length: 957 Lines: 19 I understand that ISA devices have a greater interrupt latency than PCI devices. Does this greater latency deteriorate overall system performance or just the device whose interrupts are being serviced? I've got 2 10Mbps Ethernet cards, one is an ISA card and the other PCI. I use the ISA card as a secondary net device (eth1) which is connected to a cable modem. Given that the cable modem will never saturate a 10Mbps Ethernet card, the ISA/PCI question shouldn't be relevant to networking performance. I chose to use the ISA card because it leaves another PCI slot in my box (i686-based Linux 2.4.x) available for other uses. Let me add one more thing to this context. The PCI card is a 3Com 3C590 "Vortex" so, according to the Linux doc, this device has busmastering capabilities. Is this a factor in overall system performance? Any thoughts on this? Please cc me with any responses as I am not a subscriber to this list. Thank you.