Can one use the zarlink (or something like it) on the ROACH end, and connect the fiber to an SFP+ module in the computer or switch? It seems like someone ought to make such a beast, considering there are a lot of cx-4 ports in the field that need to be connected to new CX-4 - only switches and NICs.
This is, I'm afraid, the downside to throwing in your lot with commercial products. You're at the mercy of the markets. John > I am avoiding Myricom for the reasons Rick mentioned. It took a long time > for me to get the sales/technical person to even understand that I wanted > to > go from CX4 to fiber. > > But Chelsio, as several have mentioned on this list, provides the power > necessary for transceivers to work. They also have offloading cards (which > I > believe is what you're describing) - or at least they did until the > discontinued their CX4 line. Not sure what the new Chelsio product line > will > look like and I am somewhat dubious that they will stay on the 4-6 week > timeframe. Every vendor that I and a collaborator have called are out of > Chelsio CX4 stock. > > Intel makes 10gbe cards, but the list archives are ambiguous as to whether > they power the transceivers in the Zarlink cables. > > My primary concern is that if companies already see fit to discontinue CX4 > products, then (a) it is hard to connect to the ROACH now and (b) will be > nearly impossible when something breaks in 6 years. > > How far along are the GMRT folks? > > Tom > > On Fri, Jan 28, 2011 at 6:06 PM, rick raffanti <[email protected]> > wrote: > >> The Myricom people told me they don't make NICs with active ports- ie, >> aux >> power for the fiber translator. That's why we bought the Chelsio. >> Anton is >> getting 6Gb/s throughput with the Chelsio- we haven't tried to push it >> further. I wasn't aware of the UDP packet handling stuff, though. >> >> Rick >> >> >> On 1/28/2011 5:53 PM, Dan Werthimer wrote: >> >> >> hi tom, >> >> one more note: >> >> if you use fiber optic CX4 cables, >> please see the warning at >> >> http://casper.berkeley.edu/wiki/Recommended_10_GbE_Hardware >> >> not all NIC boards have built in power to support >> fiber optic cables. check with myricom. >> the ibob/bee2/roach boards have built in power. >> >> dan >> >> >> On 1/28/2011 2:41 PM, Tom Downes wrote: >> >> So Chelsio has end-of-lifed their CX4 line. They say "4-6 weeks" until >> new >> cards come out as part of a new product line, but their sales contact >> said >> this reflected a larger recognition that CX4 is not how the industry is >> going. >> >> My thought is that I should be buying an SFP+ card and figuring out a >> way >> to convert to CX4, e.g. SFP+->optical, optical->CX4. Our cable lengths >> that >> we will (eventually) need are all greater than 15m, so outside of the >> CX4 >> spec, much less what the ROACH boards are apparently cable of driving. >> >> Is such a transceiver scheme plausible? I am having trouble finding the >> appropriate parts. >> >> Tom >> >> On Mon, Aug 9, 2010 at 8:11 AM, Matt Dexter <[email protected]> >> wrote: >> >>> Yes - when pricing switches, or any sort of (sub-)system, a full >>> BOM must be used to make a meaningful comparison. >>> >>> Matt >>> >>> >>> On Mon, 9 Aug 2010, John Ford wrote: >>> >>> And don't forget that the switches that are XFP and SFP+ sometimes >>>> (usually?) don't include the optics for each port in the switch price. >>>> >>>> With CX4, all you need is a cable, if you're within a few meters. >>>> >>>> Yes - that list is years old. >>>>> Those Fujitsu and HP switches have been tested with the CASPER >>>>> hardware >>>>> and found to work as advertised. >>>>> >>>>> There are lots of new products available. More announced >>>>> all the time. We are in contact with a number of vendors in >>>>> hopes of getting demo units to try in house with the CASPER >>>>> hardware before listing them as recommended for use. >>>>> Our tests will include running at full line rates all ports >>>>> continuously >>>>> as that's what our intended applications require. >>>>> >>>>> Less demanding applications will have many more, and >>>>> cheaper, options for suitable switch vendor and model. >>>>> >>>>> I have no prediction for when I will be able to add more switch >>>>> models will to that list. >>>>> >>>>> Matt >>>>> >>>>> On Thu, 5 Aug 2010, Andrew Lutomirski wrote: >>>>> >>>>> On Thu, Aug 5, 2010 at 3:21 PM, Matt Dexter <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> Hi Tom, >>>>>>> >>>>>>> were you aware of these ? >>>>>>> http://casper.berkeley.edu/wiki/Recommended_10_GbE_Hardware >>>>>>> >>>>>> >>>>>> Sadly the list is out of date: some of the switches are no longer in >>>>>> production. The XG700, for example, is great and cheap but you >>>>>> can't >>>>>> buy one without great difficulty. >>>>>> >>>>>> I'm not sure that manufacturers really care about CX4 anymore now >>>>>> that >>>>>> SFP+ parts are available. >>>>>> >>>>>> --Andy >>>>>> >>>>>> http://casper.berkeley.edu/wiki/Equipment_Cables >>>>>>> Matt Dexter >>>>>>> >>>>>>> On Thu, 5 Aug 2010, Tom Downes wrote: >>>>>>> >>>>>>> Casper-folks: >>>>>>>> >>>>>>>> Hoping to short-circuit a fair amount of research here in the hope >>>>>>>> that someone has had to do this already. I'll soon be looking to >>>>>>>> connect 10-20 ROACH boards by 10 gbe to a data acquisition >>>>>>>> computer(s). >>>>>>>> >>>>>>>> It seems like the smartest way of doing that is getting a 16-port >>>>>>>> switch or potentially two 8-port switches. But the 10 Gbe port on >>>>>>>> the >>>>>>>> ROACH seems to be CX4 which I take to be a less popular connector >>>>>>>> variety. >>>>>>>> >>>>>>>> What kind of switches have ROACH users out there used to connect >>>>>>>> up a >>>>>>>> bunch of boards? Are there switches out there to convert CX4 to >>>>>>>> something with a reach longer than the 15m Wikipedia quotes as the >>>>>>>> limit of CX4. 15m is very borderline for our needs. >>>>>>>> >>>>>>>> The prices seem to vary widely. We do not need network admin tools >>>>>>>> or >>>>>>>> anything fancy. In fact our data rates could probably go over 10Mb >>>>>>>> cabling, but the 10Gbe interface of the ROACH is more convenient >>>>>>>> from >>>>>>>> the firmware perspective. This is more of a multiplexer than a >>>>>>>> switch. >>>>>>>> >>>>>>>> Tom >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>>> >>>> >>> >> >> >
