[casper] SFP+ board reliability

[Rich Lacasse]

Hi All,

We've had a failure of an SFP+ board for no apparent reason.  We've not 
put any work into trouble shooting except to isolate the failure to the 
SFP+ board, as opposed to a ROACH2 or optical transceiver.


Has anyone else experienced failures?

The two PHY chips on these boards run very warm whether or not they are 
transmitting data.  We are considering putting heatsinks on them.  Has 
anyone else been down this road already?  Any other advice?


Thanks,
Rich

[casper] SFP+ board reliability

[Lincoln Greenhill]

Hi Rich,

On a related topic, we lost one SFP+ port on a board after it had been running 
for O(1) month.  We replaced it w/ another board.  The same port was dead on the 
new mezz. board pointing to the problem being w/ the ROACH2 board.


Best,
Lincoln

--
Lincoln J. Greenhill   Harvard-Smithsonian CfA
Office: 1 617-495-7194 60 Garden St, Mail Stop 42
Cell:   1 650 722-7798 Cambridge, MA 02138
FAX:1 617-495-7345 greenh...@cfa.harvard.edu
Skype:  ljgreenhillwww.cfa.harvard.edu/~lincoln

Re: [casper] SFP+ board reliability

[Jason Ray]

Hi Rich,

So far we haven't had any trouble with the SFP+ boards (8 total) in 
our vegas machine.  I guess they've been powered up continuously and 
in use for around a year now.


We were concerned about how warm the PHY chips run so I spent a 
little time looking into it.  The datasheet says:


"For typical applications, the VSC8486 can be operated in an ambient 
temperature environment of +80 degrees C with no airflow and without 
a heatsink."


It also states that the maximum specification for case temperature is 
85C (95C in one case).  I used our IR viewer and noted that the case 
temperature reached ~60degC on the bench and a little less on the 
ones in the rack.


I should note that the datasheet was for the VSC8486 so I had to 
assume that the thermal specs are similar for the VSC8488, which is 
the actual chip on the SFP+ mezz boards.


Given all of that info, we elected not to put heat sinks on ours.

Hope this helps,
Jason



At 12:25 PM 12/6/2013, Rich Lacasse wrote:

Hi All,

We've had a failure of an SFP+ board for no apparent reason.  We've 
not put any work into trouble shooting except to isolate the failure 
to the SFP+ board, as opposed to a ROACH2 or optical transceiver.


Has anyone else experienced failures?

The two PHY chips on these boards run very warm whether or not they 
are transmitting data.  We are considering putting heatsinks on 
them.  Has anyone else been down this road already?  Any other advice?


Thanks,
Rich

Re: [casper] SFP+ board reliability

[Dan Werthimer]

hi jason,

thanks for the temperature data and measurements.

were your temperature measurements in the
standard roach2 enclosure?

i think the VEGAS SFP+ PHY's are mounted
differently and have different cooling than the
standard roach2 enclosure.

best wishes,

dan





On Fri, Dec 6, 2013 at 9:53 AM, Jason Ray  wrote:

> Hi Rich,
>
> So far we haven't had any trouble with the SFP+ boards (8 total) in our
> vegas machine.  I guess they've been powered up continuously and in use for
> around a year now.
>
> We were concerned about how warm the PHY chips run so I spent a little
> time looking into it.  The datasheet says:
>
> "For typical applications, the VSC8486 can be operated in an ambient
> temperature environment of +80 degrees C with no airflow and without a
> heatsink."
>
> It also states that the maximum specification for case temperature is 85C
> (95C in one case).  I used our IR viewer and noted that the case
> temperature reached ~60degC on the bench and a little less on the ones in
> the rack.
>
> I should note that the datasheet was for the VSC8486 so I had to assume
> that the thermal specs are similar for the VSC8488, which is the actual
> chip on the SFP+ mezz boards.
>
> Given all of that info, we elected not to put heat sinks on ours.
>
> Hope this helps,
> Jason
>
>
>
> At 12:25 PM 12/6/2013, Rich Lacasse wrote:
>
>> Hi All,
>>
>> We've had a failure of an SFP+ board for no apparent reason.  We've not
>> put any work into trouble shooting except to isolate the failure to the
>> SFP+ board, as opposed to a ROACH2 or optical transceiver.
>>
>> Has anyone else experienced failures?
>>
>> The two PHY chips on these boards run very warm whether or not they are
>> transmitting data.  We are considering putting heatsinks on them.  Has
>> anyone else been down this road already?  Any other advice?
>>
>> Thanks,
>> Rich
>>
>
>
>

Re: [casper] SFP+ board reliability

[Jason Ray]

Hi Dan,

One measurement was made with a bare roach2 board just sitting on the 
bench in the lab.


The other was made with the vertical mount roach2 arrangement that we 
use in the vegas rack.


Thanks,
Jason


At 01:19 PM 12/6/2013, Dan Werthimer wrote:



hi jason,

thanks for the temperature data and measurements.

were your temperature measurements in the
standard roach2 enclosure?

i think the VEGAS SFP+ PHY's are mounted
differently and have different cooling than the
standard roach2 enclosure.

best wishes,

dan





On Fri, Dec 6, 2013 at 9:53 AM, Jason Ray 
<j...@nrao.edu> wrote:

Hi Rich,

So far we haven't had any trouble with the SFP+ boards (8 total) in 
our vegas machine.  I guess they've been powered up continuously and 
in use for around a year now.


We were concerned about how warm the PHY chips run so I spent a 
little time looking into it.  The datasheet says:


"For typical applications, the VSC8486 can be operated in an ambient 
temperature environment of +80 degrees C with no airflow and without 
a heatsink."


It also states that the maximum specification for case temperature 
is 85C (95C in one case).  I used our IR viewer and noted that the 
case temperature reached ~60degC on the bench and a little less on 
the ones in the rack.


I should note that the datasheet was for the VSC8486 so I had to 
assume that the thermal specs are similar for the VSC8488, which is 
the actual chip on the SFP+ mezz boards.


Given all of that info, we elected not to put heat sinks on ours.

Hope this helps,
Jason



At 12:25 PM 12/6/2013, Rich Lacasse wrote:
Hi All,

We've had a failure of an SFP+ board for no apparent reason.  We've 
not put any work into trouble shooting except to isolate the failure 
to the SFP+ board, as opposed to a ROACH2 or optical transceiver.


Has anyone else experienced failures?

The two PHY chips on these boards run very warm whether or not they 
are transmitting data.  We are considering putting heatsinks on 
them.  Has anyone else been down this road already?  Any other advice?


Thanks,
Rich

Re: [casper] SFP+ board reliability

[Matt Dexter]

I've had no failures I can prove are related in anyway
to the operating temperature.

Even so and mainly just because I didn't like how warm the parts felt
and had no way to access nor control 
the Vitesse parts temperature monitoring functions

I've added  these heatsinks to my ~20 SFP+ boards

15.2 x 15.x 6.35 mm heat sink black anodize w/ adhesive thermal tape
http://www.aavid.com/products/bga/375424b00034g
40 units @ @2.994

On Fri, 6 Dec 2013, Rich Lacasse wrote:


Date: Fri, 06 Dec 2013 12:25:17 -0500
From: Rich Lacasse 
To: casper@lists.berkeley.edu
Subject: [casper] SFP+ board reliability

Hi All,

We've had a failure of an SFP+ board for no apparent reason.  We've not put 
any work into trouble shooting except to isolate the failure to the SFP+ 
board, as opposed to a ROACH2 or optical transceiver.


Has anyone else experienced failures?

The two PHY chips on these boards run very warm whether or not they are 
transmitting data.  We are considering putting heatsinks on them.  Has anyone 
else been down this road already?  Any other advice?


Thanks,
Rich