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Explain high speed

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ok one thing I have never understood is the speed designations for modems and subsequently high speed connections.

a modem at 56k, gets 5.6k/s... But 56k would give an impression it's 56k/s

A dsl 256k connetion gives 25.6k/s and not 256k/s

a 512k its 51.2/s and not 512k/s

a 1.5MB connection gives 150k/s and not 1.5 megabytes per second.

a 10.0MB connection gives a 1 MB/s connection and not a 10 mega bytes per second connection.

so why are they labelled such? 512k... 256k...

256k would imply that the speed is 256,000/s which is 1 mb in 4 seconds...

what am I seeing wrong?

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The main speed designation is given in Bits and the actual speed is in bytes. You divide the first number by 8 (8 bit equals 1 byte)

56k for instance is bits per second the 5.6k is bytes per second (8 bits).

Another example the letter A is 8 bits. It takes 8 bits to code the A. So when you send the A thru your connection it's sending the A one bit at a time.

Binary code:

byte : bits

A:01000001. Your connection doesn't just send the A but it has to send each of those bits across your connection.

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Techincaly on a 56k modem connection your top speed would be 7kbs (bytes not bits) but that's only on a good day. Other factors must be taken into account like your line reception and internet speed etc.... On most days you will get 5.6kbs. The same holds true for all.

bits-----bytes

10mb----1.25mb

3mb-----375k

1.5mb---187k

56k------7k

[ 05-01-2005, 03:48 PM: Message edited by: LostInSpace ]

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so basically divide 256,000 by 8 and you get a 256k speed what it should be...same for 512 etc etc right? even though it is a little less than the figure you get when you divide by 8.

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256,000=256k

512,000=512k

256,000(256k bits) div 8 = max theoretical byte speed 32,000 (32k bytes). In other words, take A again as the example, you'll be sending 32,000 complete A's in one sec.

512,000(512k bits) div 8 = Max theoretical byte speed 64,000 (64k bytes). You'll be sending 64,000 A's in one sec.

The speed the network/modem manufacturers and high speed providers give you is in bits not bytes to make it seem like it's uber speed. They should be listing the byte speed and not the bits. Don't get me wrong it's still fast but seems a lot faster when you use the bit speed.

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I suggest everyone read SC's link. Dig through the site a bit. Find the registry entry and run it. That one thing alone seems to have helped a great deal for me.

It was so whizz bang I made it a featured topic. I hope that's ok.

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A Kilobyte= 1024 bytes or 8,192 bits.

My DSL is rated at 1.5 million bits per second downstream. In the optimum environment you could see all of that speed. But in reality, you will only see @ 80 % of it due to lag caused by network traffic and other factors.

I usually see download speeds in the 156 KB/s range. Sometimes higher. What you really want to pay attention to is the abbreviations.

IE: KB/s is Kilobytes per second as opposed to Kb/s which is Killobits per second.

Isn't Octal fun?

All of this Octal goodness brought to you by a miracle of modern electronics called the Universal Asynchronous Reciever Transmitter. UART for short.

I was required to build one in electronics school, on a bread board, using discreet components,

It had four LEDs and would add in binary up to 16 by pushing a button. Mine was the only one that worked. LOL The school bought cheap components. I bought my own. Freaked the instructor out when he asked me why mine worked and no others did.

"Simple" I told him. He did his best Tim the Toolman uuuuuh? "Switch bounce ya moron" He then did his best to come up with a switch debouncer circuit. Unfortunately there wasn't enough room left on the boards to install it.

SOB tried to flunk me after that LOL He failed.

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I tried out some of those tweaks SC....no-go for mine though....I was doing better with manual configurations. (on a cable modem here)

Haven't looked more thoroughly into it besides trying it out,but I'm thinking it's more geared toward dial-ups and the slower DSL connections...then again, EVERYone's connection and speed are going to differ regardless.

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Here's the break down with my provider:

(the image is only 91kb)

speedtest.jpg

You can only access this speed test if you are a verizon subscriber.

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Use any search engine to find an internet bandwidth speed test. I think Derek links to one as well for use in your System Profile Information.

I previously reported 1184 down using Derek's link. I used MSN speed test just a minute ago and got 1440 and 2612 for two back to back tests.

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quote:

Originally posted by LostInSpace:

Okay, Marvin what say you on this?

Hi guys!

It's very confusing that's for sure and the main reason I put up the calculator page. Microsoft themselves didn't do it right with IE so that should explain some of the widespread confusion out there about bits, bytes, megabits etc. Internet Explorer reports speed in storage units and not speed units!

My calculator is actually pretty unique because it converts speed to storage and back and forth. This is NOT normal but required because of IE's reporting style. Because of this the calculator became necessary to try and get things back to an 'apples to apples' comparison.

It's been a few years since I looked at the issue but at the time I researched it pretty thoroughly and put my findings on that page.

One thing I recommend strongly is testing against real world servers and not speed testing sites. A person is generally better off to test against sites that he will typically visit. Another consideration is that a person should test against 'known good' servers. An example would be a well-managed network like Microsoft's.

Otherwise speed testing results will not be very accurate.

BTW, I always recommend using IE for speed tests because then we can skip the whole debate on what measurement we are reporting in. Because IE holds around 98% of the market share - basically everyone has it and then we are again back to apples to apples :-)

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Hello Marvin and greetings. Agreed, depending on where you are at and who are what you download from, speed is going to vary widely. Like I've explained above the speeds given by modem and internet providers are theoretical top speeds you can obtain from devices and providers. Alas, it's not a utopia out there and your speed is dependant on other factors.

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Thanks for the welcome! I found this site when I went through my referrer logs and then saw that you were asking what I thought - so I wrote :-)

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Well, yeah....

Every sites going to be different on tests and such...but I've had a recient chance to do a test to SAME sites, but with different users and connections, all in the same town. (probably common knowledge, but I just got done talking with her online and found this out)

Mine: Mediacom cable connection (NW IOWA for both)

Hers: DSL through Verison

Overall seems we can get files almost the same time-frame...sending them mines slower (by about 40%, but thats due to my card I'm using and Mediacom not taking compressed info into them, hers accepts compression)

It all depends on the area that your in, what company your using at the time, bandwidth being used during it, compression...ect ect...

Internets a dynamic place...seen the UC servers running from 57 to 126 ping times to boot, so, all ANY testing site can do is just help give you a rough estimate at the time your doing the test really, so whether your dial-up, ASDL, Modem, whatever...if you really want a true average, use as many sites as you can throughout the world and test frequently...THEN average all the results out for yourself...Even just tests done myself between a Cable and a DSL connection in the same town seem nearly similar for smaller files...

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I normally get around 500 KB/s.

It really depends on the server you are downloading from.

If you download from a fast server that has a fast connection, you will get a better speed.

If you were to try to connect to a junky server that has dialup, you will get a slow speed.

The amount of traffic on the site can change speeds too.

Sometimes I can get up to 1.5 MB/s from some servers.

I have Comcast Highspeed BTW.

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