[vortex] Re: Gigabit NSC NIC

[Donald Becker]

On Fri, 20 Apr 2001, devdrvr wrote:

> Is anyone working on, or no about the new gigabit card and chip from
> National Semi (what is the name, and where did the ASIC come from)?

The chips are the 820 series, the DP83820 (prototype only?) and 83821.
It's NatSemi's own design.

It's based on the 810 series.  The 83815 was used on the Netgear FA311
and 312.  Some registers are moved, and addresses can be 64 bits in some
cases, so a common driver doesn't make sense.

>  Is there a Linux driver for it?

I've written a driver named 'ns820.c', and there is reportedly a driver
included with the D-Link version of the board.

>  What about performance; I hear it knocks the
> socks off the Tigon-2 based (now) 3COM card (including my MacOS driver,
> ouch).

It has on-chip checksumming, albeit implemented a little awkwardly.
Like the 810 series, it can only receive into aligned buffers so IP
headers will be misaligned.

It's a hardware implementation and thus has latency advantage over the
Acenic firmware.

>  Supposedly, Netgear bought Alteon and because they had a partnership
> deal with NSC for this new gig chip, that is why they sold the division to
> 3COM; discarding it because they didn't want it.

It's a little more complicated than that.  3Com bought only the design,
not the people (that presumably would know how to update it).

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
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