Date: Fri, 9 Jun 2000 16:52:45 -0600 From: "Kenneth D. Merry" <ken@kdm.org> To: Jin Guojun <jin@george.lbl.gov> Cc: hardware@FreeBSD.ORG Subject: Re: which is a better GigB network adapter supported in FreeBSD Message-ID: <20000609165245.A77888@panzer.kdm.org> In-Reply-To: <200006092212.PAA21446@george.lbl.gov>; from jin@george.lbl.gov on Fri, Jun 09, 2000 at 03:12:05PM -0700 References: <200006092212.PAA21446@george.lbl.gov>
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On Fri, Jun 09, 2000 at 15:12:05 -0700, Jin Guojun wrote: > I see two group of GigB network NIC listed in supported hardware. > > (1) > Alteon Networks PCI gigabit ethernet NICs based on the Tigon 1 and Tigon 2 > chipsets including the > Alteon AceNIC (Tigon 1 and 2), > 3Com 3c985-SX (Tigon 1 and 2), > Netgear GA620 (Tigon 2), > Silicon Graphics Gigabit Ethernet, > DEC/Compaq EtherWORKS 1000, NEC Gigabit Ethernet > > (2) > SysKonnect SK-984x PCI gigabit ethernet cards including > the SK-9841 1000baseLX (single mode fiber, single port), > the SK-9842 1000baseSX (multimode fiber, single port), > the SK-9843 1000baseLX (single mode fiber, dual port), > and the SK-9844 1000baseSX (multimode fiber, dual port). > > I heard from people, who use them under Linux, said that SysKonnect has > better performance (20% higher) than Alteon, but price is high ($700 : $250). I find that hard to believe. I have personally gotten 800Mbps performance from an Alteon board on Pentium II 450's. Drew Gallatin has gotten almost a gigabit out of them (988Mbps, I think). There's not much room for 20% better performance there. One thing you have to be careful about is that there are two big measures that people use for performance in high speed networking -- latency and bandwidth. My main interest is bandiwdth. People who are into clustering get more excited about low latency. The SysKonnect boards may well have lower latency, I don't know. In any case, IIRC, with the SysKonnect board, you've got a choice between jumbo frames and checksum offloading -- you can't do both at the same time. I believe the current sk(4) driver chooses jumbo frames over checksum offloading. You might talk to Bill Paul for confirmation on the jumbo frames/checksum offloading tradeoff. With the Alteon boards, you can have both jumbo frames and checksum offloading. > Just by look at the list, I think I will buy some of following NICs > and would like to get information on these NIC: > > Alteon AceNIC (Tigon 1 and 2), 3Com 3c985-SX (Tigon 1 and 2), and > Netgear GA620 (Tigon 2) from group 1, > > and/or > > SK-9842 1000baseSX (multimode fiber, single port) and > the SK-9844 1000baseSX (multimode fiber, dual port) from group 2. > > If people have used any some of these adapters can drop me the info. > about how reliable these NICs are, how is the performance and price ratio, > and what are the maximum MTUs they support, it will be appreciated. I have 12+ FreeBSD machines with 1MB Alteon ACEnics, and I would highly recommend Alteon based boards. I would recommend getting a Tigon 2 board over a Tigon 1 board. It would probably be hard to get a Tigon 1 board now anyway. You can buy the boards straight from Alteon, but it will probably be cheaper to get the Netgear or 3Com versions. The Netgear boards have 512K SRAM, the 3Com boards have 1MB SRAM, thus the price difference between the two. If you get a 3Com board, you'll want the 3c985B, the 'B' being the important part, since I think that indicates the Tigon 2 version of the board. As far as reliability, I haven't run into a bad card yet. One thing to watch out for with the Netgear boards, if you're going to use them under Windows, is that Netgear's Windows driver doesn't support jumbo frames. That's probably just a marketing gimmick, but the boards support jumbo frames just fine under FreeBSD. If you're interested in jumbo frames (you really need jumbo frames to get decent bandwidth), you should be careful about what switch you buy. The Alteon switches all support jumbo frames, but many other switch vendors don't support jumbo frames. I think Cisco supports jumbo frames on one or more of their high end Catalyst switches, but IIRC you can do VLANs or jumbo frames, but not both at the same time. One interesting thing about the Catalyst (at least the spec sheet I looked at on Cisco's web site), is that they support up to 10240 byte frames, not just the standard 9000 byte jumbo frame. (The maximum MTU is configurable.) Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message
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