ED performance over USB dongle

[SteveMaris]

A curious dumb question:

Is there a performance advantage using the Ether dongle in DMX over a standard USB dongle?
(Aside from the 4 universe to 1 aspect)

[keitha43]

If you have lots of channels (thousands) you need an etherdongle as the throughput of ethernet is much faster than USB. If only a few hundred channels USB is okay. But ethernet is the future so I recommend it.

[Steve Gase]

you are more likely to saturate the USB bandwidth.  If you use a single USB port to drive multiple dongles you are more likely to see that.  timings can also be a factor. 
 
but if you are using the recommended 50ms timing for both USB and for EtD -- you should be fine in any case.  The protocol is designed to be consistant and reliable, and the devices can meet the needed specs.
 

[charles59]

Just an fyi, the USB doesn't get saturated until tens of thousands.  I have run my own USB dongles with up to 8192 channels at 25msec update over a USB without issue.  So, I can't speak for the Lynx dongles, but the USB can handle at least 8192 channels.

[rm357]

Bandwidth should not be an issue for either configuration. Each pixelnet universe needs less than 1Mbps of bandwidth. Even the original slow USB (12Mbps) could probably run 6 USB dongles on a single usb connection using an external hub.

I doubt if the Ethernet module can handle gigabit Ethernet. Technically usb2 is almost 5 times faster than 100Mbps Ethernet, but I'd be willing to bet that the Ethernet implementation is more efficient...

The etherdongle gives you 4 universes to play with while the USB dongle only provides 1.
This goes for both pixelnet and DMX firmware configurations.
- you would need 4 USB dongles to have the same number of channels available as a single etherdongle.

[Jeffl]

I think it's more of a timing issue.  I'm not sure if either the USB dongle or ED are timed down to 25ms or if this has even been published.  I do know that for spot on choreography 25ms is nice but you need software and hardware that support both.  For me, 50ms just doesn't cut it.  I do know that the LE's do appear to support 25ms.

[Nonamefril]

Not to hijack this thread but there wouldn't be any future with USB3?   5 Gbit/s is alot

[chrisatpsu]

the EtherDongle seems to be the future...

[rm357]

5Gbps...

You got 100,000,000 channels you need to control?

For most of us non-millionaire types, a few etherdongles will provide more channels than we can responsibly afford.

Also remember that DLA is for personal, non-commercial use...

[Jeffl]

And for those of us without pixels "one" etherdongle will provide more channels than we can responsibly afford or care to deal with.

[Nonamefril]

5Gbps...

You got 100,000,000 channels you need to control?

For most of us non-millionaire types, a few ether dongles will provide more channels than we can responsibly afford.

Also remember that DLA is for personal, non-commercial use...

LOL Im far from a millionaire,I was just suggesting if we changed out a few things on the USB dongle and brought it up to USB 3 standards then couldn't that me another approach instead of the ether dongle?USB 3 is backwards compatible so it could be used on older USB inputs also.There is a update coming for it too to increase it to 10Gbps....I dunno that's why I asked,why USB 3 dongle could be a contender just as much as ether dongle in the light realm.....btw rm357 Im almost your neighbor,Im down here in Dublin,so i know I gotta make a trip up there to check out your light display.

[rm357]

In 2012 I ran out of time and threw in the towel...

Ideas are starting to gain momentum for 2013, but my display is my 3rd hobby, so we'll see how it goes this year...

Robert

[tbone321]

The cost of a USB 3 dongle would probably cost more than the Etherdongle so what would be the point.  The idea here is to keep costs down while not killing RJ.  The origional USB dongle was (and still is) a great device that allowed us to control a full universe of DMX at an affordable cost.  Prior to RGB, one DMX universe was more than enough for just about any of us but now......  With the introduction to low cost RGB, and neat tools like the Nutcracker, even one Pixelnet universe is not enough.  The design and plan of the Etherdongle is to be able to handle a just about limitless number if channels without the need of a PC at all once the show is created.  This is something that the USB dongle will never be able to do.  While the USB dongle is still a usable device, I believe that with the evolution of the hobby, it is at its end of life.  To develope it any further would really be wasting time.

[RJ]

I agree it would be like adding better tires to a model T car to try and make it work in the modern world.

As far as USB 3.0 and the need for the larger bandwidth I see the bandwidth as not being the limit currently. when I see people talking about needing more bandwidth and not being able to live with the 50ms timing of SS cause they need the faster 25 ms updates I grin. You see we cant control stuff at such fast timing reliably on computers we use. most of us are running windows and the timing is not that acurate even on Ethernet.  We see a few millisec varations even with it coming out of the computers. Unless you run a real time operation system on dedicated hardware to handle it you are not controlling the timing that close. The human eye can not precieve changes under about 35ms. Movies a few years ago where on film and updated at 41ms intervals (24 frames per second) and no one complained about that. The sound from you radio in your car is about 2 feet from speaker to your head normally and at the speed of sound takes approximately 3 ms to travel to your ears. This is after the delay of being broadcast and received and put to the speaker. So likely 4 ms delay in it. Ok so put speakers in your yard and the viewers are 20 feet away. the delay to them would be in the order of 30 ms. So see the varations in our settings alone add more than 25 ms difference in our sync of lights to show. So it becomes almost silly to think that the difference of 25ms to 50ms would be a big issue. When
I started this hobby just 5 years ago most all of us were using 100ms timings and that seemed fine.  I think we sometime take things too far for the impress factor.  Ethernet is the best way to get the data from the computer and then the rest depends on what you need or want from there.

RJ

RJ

[PJNMCT]

Good tip on sound performance!

Thanks RJ.

-Paul