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Date: Sat, 27 Jul 2013 18:22:18 +0200
From: Andre Oppermann <andre@freebsd.org>
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To: "Alexander V. Chernikov" <melifaro@FreeBSD.org>
Subject: Re: Recommendations for 10gbps NIC
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Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>,
 Luigi Rizzo <rizzo@iet.unipi.it>
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On 27.07.2013 10:42, Alexander V. Chernikov wrote:
> On 27.07.2013 12:15, Luigi Rizzo wrote:
>> On Sat, Jul 27, 2013 at 10:02 AM, Alexander V. Chernikov
>> <melifaro@freebsd.org>  wrote:
>> This makes me curious because i believe people have used netmap with
>> the 82598 and achieved close to line rate even with 64-byte frames/one port,
>> and i thought (maybe I am wrong ?) the various 2-port NICs use 4 lanes per port.
>> So the number i remember does not match with your quote of 2.5Gt/s.
>> Are all 82598 using 2.5GT/s (which is a gen.1 speed) instead of 5 ?
 >
> Quoting 82598EB datasheet:
> The PCIe v2.0 (2.5 GT/s) interface is used by the 82598EB as a host interface. It supports x8, x4,
> x2 and x1 configurations at a speed of 2.5 GHz. The maximum aggregated raw ban..
>
> Actually I discovered this exactly with netmap and 82598*-DA2 NIC :)

Discussing the 82598 is moot because it has been replaced with the 82599
which supports x1-x8 at 5 GT/s.  AFAIK you can't event buy the 82598 anymore.

-- 
Andre