[SunRescue] Sparc 2, Linux and ethernet

[nick at snowman.net]

I'll have to disagree with that (somewhat).  You're right about the PCI
bus, but it's only burst.  (spec is PCI will burst to 133MB/s, just a
hair over gigabit)  However all 4port cards I've dealt with (mostly the
newer adaptec starfire) use 64bit pci, and sometimes even 66mhz, which
kicks you up to ~500MB/s.  This is enought for Lots (tm) of 100Mbits
ports.  I have gotten in the mid to low 90Mbits/second going between a
pair of PII's using 3C905's, so I don't doubt if you mucked with things
and elimitated tcp ip and other overheads you could get VERY close to
100Mbits.  As a side note, most cisco routers and switches (C3524 as an
example, a 24port 10/100, 2port 1000 switch) have pci.  It's not obvious,
and you can't stick in pci cards, but the bus is still pci.
	Nick
PS, how much do ppl here know about gigabit?  I can't get mine to go over
300Mbits/s 

On Thu, 17 Aug 2000, Gregory Leblanc wrote:

> > -----Original Message-----
> > From: apotter at icsa.net [mailto:apotter at icsa.net]
> > Sent: Thursday, August 17, 2000 7:10 AM
> > To: rescue at sunhelp.org
> > Subject: Re: [SunRescue] Sparc 2, Linux and ethernet 
> > 
> > > Right now I have an old Intel box that I use as a router.  
> > It runs RedHat 
> > > Linux, and has three PCI ethernet cards that Linux 
> > recognizes as eth0, 1, 
> > > and 2.  Works fine.
> > > 
> > > However, its old, and, since it is my router, if it dies, 
> > the whole net is 
> > > down.
> > 
> > My solution to this was a newer (also surplus) WinTel board, 
> > three PCI quad ethernet cards and OpenBSD (linux disn't line 
> > the cards).
> 
> I just did the math real quick here.  
> 32-bits times 33MHz yeilds a throughput of 132MB/sec.  
> 12 ports at 100Mbit yeilds a throughput of 150MB/sec.
> 
> So, uhm, those had best not be all 100MBit ports.  I doubt that you can get
> even 100MBit from a standard P-II/III motherboard, probably much less with
> older boards.  Not that you'll be using that much bandwidth, but that's
> certainly more than it can handle.  That's probably why none of the
> commercial switches/routers use PCI.  :-)
> 	Greg
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