RE: [10GBASE-T] Power Down mode
Thanks Hugh! We definitely agree on that point... and especially about
overtaking EFM. ;-)
Cheers,
Brad
-----Original Message-----
From: Hugh Barrass [mailto:hbarrass@cisco.com]
Sent: Wednesday, August 06, 2003 2:40 PM
To: Booth, Bradley
Cc: stds-802-3-10gbt@ieee.org
Subject: Re: [10GBASE-T] Power Down mode
Point taken!
I think that the discussion should return to the PAR+5. We have seen
that there are many interesting topics that we can discuss
AFTER WE START THE TASK FORCE!
(sorry for the shouting, but I think we are in danger of putting the
cart before the horse).
We need to agree that the project is worth submitting and after the PAR
is approved we can entertain many interesting proposals for the project.
Nobody is pretending that it will be easy and I expect that we will have
to weigh a number of proposals before we can find the right baseline for
this project.
Don't forget, we need to get the PAR ready for the November plenary if
we are to stand any chance of overtaking the EFM project :-)
Hugh
Booth, Bradley wrote:
>Hugh,
>
>Not if you comply with 4.2.7.5 in 802.3ae. :-) There is no "may" in
>there as far as half duplex and 10G are concerned.
>
>Cheers,
>Brad
>
>-----Original Message-----
>From: Hugh Barrass [mailto:hbarrass@cisco.com]
>Sent: Wednesday, August 06, 2003 2:14 PM
>To: Booth, Bradley
>Cc: stds-802-3-10gbt@ieee.org
>Subject: Re: [10GBASE-T] Power Down mode
>
>
>Brad,
>
>I was waiting for the fireworks to start :-)
>
>My tongue was in my cheek when I suggested half-duplex, particularly
>seeing how unpopular it was for Gig. One point though, the MAC for
>10GBASE-T may support HD if it has to work in 10/100/1000/10G autoneg
>mode...
>
>Hugh.
>
>Booth, Bradley wrote:
>
>
>
>>Hugh,
>>
>>What is half duplex? :-) Seriously though, before all the other
>>
>>
>802.3ae
>
>
>>and 10GbE experts jump on you, there is no half duplex in 10GbE. The
>>802.3ae MAC is full duplex only. Although EFM is using half duplex in
>>an interesting way to stall the MAC, we haven't seen anything like
that
>>proposed for 10G.
>>
>>Let's see if we can get the PAR, 5 Criteria and Objectives done first,
>>then we can toy with other concepts to reduce power or data rate.
>>
>>Thanks,
>>Brad
>>
>>-----Original Message-----
>>From: Hugh Barrass [mailto:hbarrass@cisco.com]
>>Sent: Wednesday, August 06, 2003 12:27 PM
>>To: Fakterman, Boris
>>Cc: stds-802-3-10gbt@ieee.org
>>Subject: Re: [10GBASE-T] Power Down mode
>>
>>
>>
>>Boris,
>>
>>This would only really be useful for battery powered equipment. Most
>>systems will be required to sustain maximum rate traffic and therefore
>>the idle periods will be less than 1% of the time.
>>
>>Another possibility is half-duplex. If the pre-coding and pre-emphasis
>>is balanced well with the equalization & decoding then it may be
>>possible to make a half-duplex transceiver consuming half the power of
>>
>>
>a
>
>
>>full-duplex one. Of course there may be problems with collision radius
>>
>>
>&
>
>
>>bursting, but this could enable some early implementations to use HD
>>while the boffins are working on power reduction techniques.
>>
>>Hugh.
>>
>>Fakterman, Boris wrote:
>>
>>
>>
>>
>>
>>>Hello all,
>>>
>>>Following the discussion regarding power, it looks like there is a
>>>consensus that the 10Gb Phy dissipated power will be very high at
>>>first silicon and relatively high at advanced future versions.
>>>
>>>The average power is important for most problematic topics, such as
>>>thermal conditions, power source availability and so on.
>>>
>>>The average power can be reduced by using the Power-Down mode. The
>>>transceiver does not transmit or receive data during significant
>>>periods of time. Instead of transmitting idle symbols while consuming
>>>full power, the system can enter the Power-Down mode. The transmitter
>>>power can be reduced by stopping the transmission, the receiver power
>>>can be reduced as only minimal receive functions will be active. The
>>>overall dissipated power during the Power-Done can be reduced
>>>significantly.
>>>
>>>Of course there are algorithmic issues to solve, such as how to
>>>maintain the synchronization during the Power-Down mode, but these
are
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>>technical problems that can be discussed and solved.
>>>
>>>The average power with implemented Power Down mode depends on the
>>>length of idle periods.
>>>
>>>The desktop/laptop PC transmits idles most of the time ( > 90% ?). I
>>>don't know what happens in data centers.
>>>
>>>.If we can reduce even half of the dissipated power by the Power Down
>>>mode, it is worth to be considered.
>>>
>>>Regards,
>>>
>>>Boris Fakterman - Intel Communications Group, Israel
>>>
>>>Tel: 972-4-865-6470, Fax: 972-4-865-5999
>>>
>>>mailto:boris.fakterman@intel.com
>>>
>>>
>>>
>>>
>>>
>>
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