[Beowulf] Re: newbies' dilemma / firewire? (Hahn)

Michael Will mwill at penguincomputing.com
Thu Mar 9 12:55:09 PST 2006

Infiniband with DDR is already at 20Gbps over CX4 copper


From: beowulf-bounces at beowulf.org [mailto:beowulf-bounces at beowulf.org]
On Behalf Of Ed Karns
Sent: Thursday, March 09, 2006 10:35 AM
To: beowulf at beowulf.org
Subject: [Beowulf] Re: newbies' dilemma / firewire? (Hahn)

On Mar 8, 2006, at 12:00 PM, beowulf-request at beowulf.org wrote:

	... that's nice marketing-speak, but content-free, I'm afraid.
... though I have to say I really don't expect optical WDM firewire to
make any difference ;) ... I'd personally love to see something better
in every way than GBE/10GE, but just don't see it happening.  no,
please, don't suggest IB :)

Well, it can, does and will make a difference "real soon, now",
considering that since metal conductors are close to the upper
throughput limits dictated by the laws of physics and laws of
diminishing returns. Pushing more data through a metal conductor, beyond
several Gigabits per second, requires more and more power over shorter
and shorter metal conductors ... and considering power (heat) and cross
talk (noise) v. conductor length (of antenna) ... you sure don't want to
open an active box as the microwave radiation could fry your gonads
(resulting legal action being the main reason no one is seriously
promoting 20 or 30 Gigabit Ethernet over wires).

Intel (et al) is seeking alternates to the above:
http://www.intel.com/technology/silicon/sp/ ... data transfer over
packet switching networks using multiple frequencies (multiplexed
"colors") and approaching Terabits per second over a silicon glass fiber

Key point: determination of the protocol of choice for this "Glass Bus".
Candidates include packet switching and non-packet switching protocols:
FireWire, USB, SATA, PCI (e or other), Fibre Channel, iSCSI / SAS,
InfiniBand, EtherNet and possibly others ... and considering that
FireWire is the most hardware/ firmware efficient for a given
microprocessor speed, having the most hardware efficient, packet
switching network and being peer to peer topography ... 

Thus the previous discussion(s) Re: " ... Why is it comparable to or
faster from a processor running at around 40% of GigaBit processor
speeds? Processor efficiency FireWire has a 32-bit "risc" type
microprocessor, is peer to peer in hardware / firmware and has other
lean architecture features. (Small address space, data frame large =
more efficient data packet over double duplex connections.)

(Picture this: a coffee can containing multiple processors on multiple
circuit boards in close proximity fanning out from a central glass rod
or fiber running through the axis ... linking to other coffee cans ...)

EOR = end of rant

Ed Karns

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.beowulf.org/pipermail/beowulf/attachments/20060309/9c27ea3f/attachment.html>

More information about the Beowulf mailing list