Hi,

Thanks for the response.  I can get about 4meg/sec through one of the hme at 
a time.  I didn't necessarly expect it to be faster, but, if one has the
hardware sitting around it's always interesting to make things faster.

Thanks for the pointer to the Sun document as well.

cheers

bruce

On Tue, Mar 07, 2006 at 10:47:55AM +0000, Julian Coleman wrote:
> > 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
> 
> -- 
>   My other computer also runs NetBSD    /        Sailing at Newbiggin
>         http://www.netbsd.org/        /   http://www.newbigginsailingclub.org/

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