[Beowulf] Re: 48-port 10gig switches?

Rolf McClellan rolfmcc at mcclellanconsulting.com
Thu Sep 30 12:20:49 PDT 2010

Tom Ammon <tom.ammon <at> utah.edu> writes:

> Interesting. Although, I'm still not convinced it's a single switching
> asic. The switch chip is, of course, not the only "chip" in the switch.
> This article says the "networking protocols" run on a single chip. The
> official Voltaire press release at
> doesn't say anything about a single switching asic - perhaps the author
> made an assumption about the product? You'd think they would really
> tout the fact if they had a single chip that dense.
> Last time I talked with the Arista people, their nonblocking 48 port
> switch (one of two options for a 48-port switch, IIRC) was not a single
> chip - it was a non-blocking 6-chip CLOS design. And, I agree, the
> price was compelling.
> So I still think there's not a 48 port 10GbE switch chip, at least not
> in merchant silicon. I don't know much about what cisco is cooking up
> on 10GbE. I know Juniper was rebranding BNT (which was fulcrum-based).
> I also heard about Extreme's top of rack 10GbE but it was only 24 ports
> - you have to stack two of them together to get 48 ports. 
> So my answer to your original question is that since there's not
> single-chip 48p, you still have to chain together 24-port chips to get
> line-rate 10GbE performance. I'm happy to be corrected, of course - but
> a seemingly misguided statement in an article in the trade press
> doesn't seem like a very good product announcement for an innovation
> like that. 
> Tom
> On 09/02/2010 12:00 AM, Greg Lindahl wrote:
>   Press about the new Voltaire 6048 48p 10g switch indicates that it's a
> single switch chip:
> http://www.theregister.co.uk/2010/08/30/voltaire_vantage_6048/
> Arista seems to have a similar product at a similarish list price, and
> that list price is a lot less than chassis switches using 24p silicon.
> Fujitsu isn't selling a 48p switch, and I'm not up enough on silicon
> vendors to tell you if Fulcrum is still the only other vendor. I
> used to know this stuff, then I left HPC to build a search engine 

This is from a Marvell press release:
The Prestera CX family is the first commercially available solution to offer up 
to 48 ports of 10 Gigabit Ethernet (GbE) on a single chip, and the first with 
multiple ports of 40GbE with line rate throughput.  These packet processors 
provide 480Gbps full duplex throughput for Carrier Ethernet, including Mac-in-
Mac, Multiprotocol Label Switching (MPLS), Virtual Local Area Network (VLAN) 
Translation and IP Routing and can support up to 128K subscribers with a single 
device to meet the exponential growth of Internet traffic and massive 
deployments of high speed optical broadband networks.  

The Prestera CX family's reduced XAUI (RXAUI) interface enables doubling of the 
switching capacity for current broadband access platforms while maintaining 
compatibility for legacy line cards, enabling in-field upgrade of access 
platforms as networks migrate to GPON and 10G EPON.

For Converged Enhanced Ethernet (CEE) networks in next generation datacenter 
deployments, the Prestera CX family offers a highly differentiated feature set 
including the industry's first commercially available 40GbE ports, Priority Flow 
Control and Fiber Channel over Ethernet (FCoE) capabilities including Fiber 
Channel Awareness and Fiber Channel Forwarding.

Multiple reference designs based on Prestera CX are available from Marvell, pre-
loaded with software for enterprise and datacenter switching.  These include a 
single rack unit 48 port 10G SFP+ solution as well as a modular 40 port 10G SFP+ 
solution with two ports of 40GbE uplinks.

More information about the Beowulf mailing list