Thanks Matt and John for your input. You have provided needed
guidance for on the performance of copper cables. I may well give the
Gore a try, I have no objection to paying less. I do wonder, though,
if our good experience with 3 m lengths might be related to our use of
Fujitsu (??). Matt, yes I had read the cables & parameters memo. It
did not really really cover fiber optics though (the modifications
needed on an iBOB or BEE2 to retrofit, and sources for cables). Your
response fills this gap---I am sure I'm not alone in wanting to hear
how the PARALIGHT and ZARLINK stuff works out.
In our case, given that we can stick with short cables and have not
yet hit problems with the copper even at 3 m, we'll steer clear of the
cost and complication of F/O for now.
Just to clarify:
At HCRO for ATA we are going to use
iBob -> BEE2 1m copper or 3 to 10m fiber optic
iBob -> F Board 1,2 and 3 m copper (more testing TBD on 3m)
BEE2 -> BEE2 1m and 1.5m
BEE2 -> iBob 3 to 10m fiber optic
It appears you don't trust even 3-m copper on iBOB->BEE2. How bad is
it in your experience?
What is "F Board?" A non-CASPER FFT design . . .?
The third case is 1 m and 1.5m copper, right?
Also, I am probably missing something, but what is the relevance of
the discussion of cooling, pitch and mounting plate modifications in
the context of fast serial?
All of our iBobs will have fans mounted to the FPGA's heatsink
5VDC fan 40x40x6mm fan, digikey GM0504PEV1-8GN
5.9CFM Sunon GM0504PEV1-8GN
and the aluminum mounting plate is hogged out so that they can
still be mounted on 8hp = 1.6" pitch. These fans are in addition
to the chassis level fans (cold air in at bottom front; warm aire
out at top back).
On Aug 19, 2008, at 5:16 PM, John Ford wrote:
(I have re-read a prior thread from early May on this topic involving
John, Matt, Jouko, and Francois, however the sourcing information was
from 2005, and the applicability of the information to our situation
was not entirely clear from the conversation. Also perhaps more has
been learned since May.)
Our experience here is limited to using the GORE cables for both 10
GbE
and XAUI. The iBOB and BEE2 seem to be particular about needing short
cables. We use 1 meter cables on our iBOB to BEE links. longer
cables
seem to work with 10 GbE cards (myricom) and commercial switches
(fujitsu). We bought our latest cables along with our latest
myricom 10
GbE cards from bell electronics, a Myricom distributor.
Hope this helps!
John
