Stories
Slash Boxes
Comments

SoylentNews is people

posted by Dopefish on Thursday February 27 2014, @09:00AM   Printer-friendly
from the super-fast-downloads-of-animated-gifs dept.
visaris writes "Phys.org reports researchers at IBM have set a new record for data transmission over a multi-mode optical fiber. The record data rate of 64Gb/s was achieved over a cable 57 meters long, using non-return-to-zero (NRZ) modulation with a type of laser called a vertical-cavity surface-emitting laser (VCSEL). Researcher Dan Kuchta notes, "Others have thought that this modulation wouldn't allow for transfer rates much faster than 32 Gb/s." Indeed, many researchers thought that achieving higher transmission rates would require turning to more complex types of modulation, such as pulse-amplitude modulation-4 (PAM-4). The achievement demonstrates that standard, existing technology for sending data over short distances should be able to meet the growing needs of servers, data centers and supercomputers through the end of this decade, according to the researchers. "What we're showing is that [...] this technology has at least one or two more generations of product life in it," says Kuchta."
 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 3, Informative) by NecroDM on Thursday February 27 2014, @02:44PM

    by NecroDM (376) on Thursday February 27 2014, @02:44PM (#7966)
    True, at 57 meters it's usefulness is limited to datacenters and supercomputers that are in its range however since it's optic fiber latency shouldn't be an issue afaik. Here's wiki reference regarding latency on optic fiber (it's the speed of light/1.5 in average) - http://en.wikipedia.org/wiki/Latency_(engineering) #Fibre_optics [wikipedia.org]
    Starting Score:    1  point
    Moderation   +2  
       Informative=2, Total=2
    Extra 'Informative' Modifier   0  

    Total Score:   3  
  • (Score: 1) by davester666 on Thursday February 27 2014, @06:53PM

    by davester666 (155) on Thursday February 27 2014, @06:53PM (#8080)

    Well, it just happens to be long enough to connect to the NSA room...

  • (Score: 3, Informative) by Angry Jesus on Thursday February 27 2014, @07:03PM

    by Angry Jesus (182) on Thursday February 27 2014, @07:03PM (#8086)

    however since it's optic fiber latency shouldn't be an issue afaik.

    Over short distances, like interconnects, latency is mostly a function of the transceiver and receiver electronics than it is of the fibre (or copper). That includes protocol overhead (error correction, packetization, clocking, etc) too.

  • (Score: 3, Informative) by TheRaven on Friday February 28 2014, @09:23AM

    by TheRaven (270) on Friday February 28 2014, @09:23AM (#8385) Journal
    As the other poster said, the latency over the fibre is not the limit. Unless you have an optical processor, at both ends you need to convert the optical signal into an electronic one. This adds a fairly noticeable amount of latency, typically more than using an electrical signal over the length for short runs. This gets significantly worse when you have a switched network, rather than a point-to-point connection, because the switches are also electrical (there are some research prototypes of purely optical hubs, but nothing in production that I'm aware of), so every switch involves an optical-electronic-optical conversion, plus the switching / buffering time. This can add up to several ms, which can completely offset the improvement in bandwidth for anything remotely synchronous.
    --
    sudo mod me up