> Is there any dis/advantage to using a quad hme card vs individual hme 
> cards in terms of throughput for ethernet on a sparcstation 20?
> Silly question perhaps, but, I can set up my firewall system with
> 1 quad or 3 individual cards and, since it's basically all the same to me,
> I'd prefer the highest performance.

Looking at Sun's PCI:SBus Comparison document:

  http://www.sun.com/products-n-solutions/hardware/docs/pdf/805-7410-10.pdf

I see that SBUS is 25Mhz, 32-bit maximum and maximum of 100MBytes/s.  I
assume your SS20 is running at 25Mhz (I think that some of the older/slower
processor modules want the bus at 20Mhz).

If you want to saturate a single 100Mbit/s interface, you'll need to transfer
200Mbit/s (100 in, 100 out).  This is roughly 25Mbytes/s, so a 25Mhz, 32-bit
SBUS in a SS20 can theoretically saturate 4 HME interfaces.  However, there
is also software processing to do.  I don't know how much CPU you need to run
an HME at 100Mb/s.  I could probably test with a single HME.

What data rate do you expect on your 3 interfaces?

J

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