[dms]

I never understood why most of the people out there think that fiber optic sends better quality signals than signals over copper...


If I send a 1010'1010 in the fiber, and I'll send 1010'1010 on copper... Well it's the same result!!!!!!!


Talking about speed, well it just depends on the circuity speed... Not really on the fiber... We can have a slow clock speed circuity well in that case fiber is worthless!

In any case the new FireWire runs at 3Gb/s it isn't bad at all for video processing!



If we stay on the fiber, well the most advantage is that on long distance we don't need to amplify the signal, in stead with copper, we often have to do this work on long distance.

It's about 1/10 = copper distance / fiber distance.


Anyways there are two kinds of fiber used:

mono mode and multi mode.

Multi mode is used in slow applications. The light bouces in the fiber making it slower to get to the other side.

Mono mode is used in telecomunication. The light stay in the center part of the fiber making it extremly faster.


The most important thing is not to make to make short angles (such as 90°). The signal would bounce outside the fiber.

[GoatIronMaidn]

I'm more concerned with the whole firewire vs. USB vs. parallel debate. Since I do minimal video editing, a few extra seconds isn't going to kill me either way. My problem is which will suck up the most CPU and memory resources when I plug it in. If I already have PS open, for instance, which one is going to deplete my resources the least?

I have a video camera and digital camera which can use either USB or firewire. I currently run both through USB. I have no clue what the rate is, but I can download 100 photos (1600 X 1200) in about ten seconds from the camera and the video seems to go pretty fast too. Since neither wire is over ten feet long, does the internal componant really matter? Or is that for longer distances, like DSL and T1?

[dms]

Well for istance USB cables can't get too long even if it works on differential signals.

I have an entire book about USB! So I think you might know that there is slow-speed and full-speed in USB1.1 and high-speed in USB 2.0.

slow-speed: 1.5Mbit/s
full-speed: 12Mbit/s
high-speed: 480Mbit/s

What do you mean with PS? Urgh...

Anyways if you have two peripherals attached in the USB everything depends on the speed that your peripheral uses. So it's not like, devided by two or so! USB also has different kind of communication. Bulk, Control, Interrupt and Isochronous.

For example if you have a USB printer, you really need to check for errors, so that what you print is correct and everything, this might makes things quite slower (you won't notice it). But if you have video streaming, we really won't care if every once a while a couple of pixels are wrong etc... Depending on your application you the developer chooses the communication type. Time-critical or accurate-data. And this will effect on the final speed. So it doesn't really care if your device uses full-speed or something else. It depends really on what it does.


Actually yes (finally replying to your question) it is for longer distances when we talk about networks etc.

[Cookie Mobster]

Absolutely right... speed isn't what is in question ever; it is bandwidth, which sadly is often referred to as speed... Both copper and Fiber transmit at about the same rate (186,000 mi/sec).

I think that fiber is just becoming popular because advancements in production of fiber are happening more rapidly than copper. They expect that making fiber capable of ultra high bandwidth will cost a considerable amount less than copper of the same class.

Plus enticing users to replace old lines is a very good business practice.

[dms]

When people think of fiber optic, they think at light, light speed, which is right, but light speed is referred as the time that the ray crosses the whole fiber and not at the speed of communication between the two "boards" (if you wanna call them like this) on the ends. The same thing is with copper, how much time an electron takes to get to the other side... Well here it's much different because it's like having balls one after the other one. And as soon as you push one from one side, right at the same time, at the other extreme of the copper, another ball moves...

Anyways another thing that they do with fiber is mixing colors in the fiber and then filter them out to have all the signals seperated. If we work in digital with copper we really can't mix signals in the same time, it's different if we work in analogic. Well fiber has its advantages, the fact that we have no need to amplify a signal on long distance it's really good.

LOL anyways I hope I'm not getting too much people bored here...

[dms]

I think that the next distussion will be digital vs analog LOL

[The Neoracle]

smckone, on Dec 4 2002, 10:37 PM, said:

Both copper and Fiber transmit at about the same rate (186,000 mi/sec).

I thought copper was slower due to resistance? That's why computer mobo's are stamped with Gold not copper? Gold is MUCH less resisant.

Also, that's why you hear an echo if you call Japan from New York and the call doesn't go by Satelite.

[Cookie Mobster]

I think you misunderstood me, I said they transmit at lightspeed not electricity flows at light speed. It is a little lower sure, but what is a few thousand miles a second anyway

Here try this:
http://newton.dep.an...5/eng/ENG51.HTM

[dms]

In hardware, just the pin connections are made of gold, the rest is made of normal copper. This because gold is much much less oxidant than copper, that's the only reason! Well the fact of the satellite, you have to know that a satellite transmits in GHz frequency. And all the satellitete's circuits are made of a special semiconductor, faster (about 10 times) than silicon. If you have a chip made out of silicon, and you have the same one made of GaAIA you can go 10 times faster. The bad thing of this kind of semiconductor is that it's poison.
The fact of an echo is because of your signal coming back. It's not because it takes less than a few seconds to get there! Signals come back per example when you have an antenna and you have to transmit a signal in the air and you don't use full power to do it. You have a generator, a resistance, and the antenna (that's a resistance). The antenna and the resistence have to be the same value to transmit full power to the antenna and to not have signals that you transmit, coming back.

Anyways the fact that copper has resistance it's nothing than more true: that's why on long distance you need to amplify the signal many times.