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"Bit Measuring Contest" - Odell


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(I thought I would segregate this wildly off-topic, yet informative, debate from the discussion Current State of Sprint. Thanks to Odell for the inspiration of the thread title. - Duffman)

 

Actually, to further clarify, bits are the basic unit of measurement for data. They are the 1s and 0s that build the data we see. A byte, on the other hand, refers to the amount of bits required to encode a single character of text. Currently, this is generally accepted as 8 bits, but it has varied in the past.

This is why bytes are more suitable for referring to storage capacity, where bits are more suitable for referring to digital information transfer. Your internet connection will only deliver so many 1s and 0s, no matter how your computer uses them to put together the transmitted data.

 

Sent from my Galaxy Nexus using Tapatalk 2

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Actually, to further clarify, bits are the basic unit of measurement for data. They are the 1s and 0s that build the data we see. A byte, on the other hand, refers to the amount of bits required to encode a single character of text. Currently, this is generally accepted as 8 bits, but it has varied in the past.

This is why bytes are more suitable for referring to storage capacity, where bits are more suitable for referring to digital information transfer. Your internet connection will only deliver so many 1s and 0s, no matter how your computer uses them to put together the transmitted data.

 

Sent from my Galaxy Nexus using Tapatalk 2

 

Warning: Nerd content ahead!

 

8-bits do make up a byte but that does not mean it is the storage space for a single character. Unicode separated the concept of "code points" (the visual symbols we think of as letters, numbers, etc) from the encoding (the format used to store them). These days a lot of stuff is UTF-8 which uses 1 byte for US English characters and from 2-4 bytes for others. UTF-16 uses 2 bytes for most code points in the most common languages with the benefit that it typically doesn't vary so you can jump forward in a string without having to examine all the bytes in between.

 

 

Not to mention for network transfers, you have overhead that makes your effective transfer speeds lower because not all the bits are used for your content.

 

 

Anyway for historical reasons network transfer speeds are often quoted in bits per second, so 1Mbps is 1024*1024 bits per second. Divide by 8 to get the MB/s. Oh yeah I forgot to mention that bits/bytes are usually measured in multiples of 1024 because in binary 1024 is a direct power of 2 (equivalent to 1000 being a direct power of 10, which is why we insider it to be a "round" number.... Similarly computer systems often stick to "round" numbers only in base 2).

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a6fa6572-c2a2-7049.jpg

 

Megabits per second

 

Sent from my Galaxy Nexus using Tapatalk 2

You on 3G, 4G, or WiFi

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Warning: Nerd content ahead!

 

 

Not to mention for network transfers, you have overhead that makes your effective transfer speeds lower because not all the bits are used for your content.

 

 

Anyway for historical reasons network transfer speeds are often quoted in bits per second, so 1Mbps is 1024*1024 bits per second. Divide by 8 to get the MB/s. Oh yeah I forgot to mention that bits/bytes are usually measured in multiples of 1024 because in binary 1024 is a direct power of 2 (equivalent to 1000 being a direct power of 10, which is why we insider it to be a "round" number.... Similarly computer systems often stick to "round" numbers only in base 2).

 

1Mbps is not equal to 2^20 bits/sec. They use powers of two in reference to memory and cpu addressing. Network speeds and storage (i.e. Hard drives and such) use powers of 10. See table on top right here http://en.wikipedia.org/wiki/Binary_prefix.

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1Mbps is not equal to 2^20 bits/sec. They use powers of two in reference to memory and cpu addressing. Network speeds and storage (i.e. Hard drives and such) use powers of 10. See table on top right here http://en.wikipedia.org/wiki/Binary_prefix.

 

No, only hard drives use powers of 10. Network transfer speeds are definitely powers of 2.

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Hard drives used to use powers of 2 years ago. Then they changed and most operating systems didn't follow suit until Mac OSX Show Leopard in 2009. It was weird when I discovered that was how Apple saved hard drive space.

 

Edit: Correct me if I'm wrong, but I don't even thing Windows changed to power of 10 for hard drive sizing in the operating system yet.

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Network transfer speeds are definitely powers of 2.

 

Nope, they are in powers of 10.

 

http://searchstorage.techtarget.com/definition/Kilo-mega-giga-tera-peta-and-all-that

 

Power-of-10 multipliers are also used to define binary data speeds. Thus, for example, 1 kbps (one kilobit per second) is equal to 103, or 1,000, bps (bits per second); 1 Mbps (one megabit per second) is equal to 106, or 1,000,000, bps. (The lowercase k is the technically correct symbol for kilo- when it represents 103, although the uppercase K is often used instead.)

 

Original link I gave says the same thing.

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Nope, they are in powers of 10.

 

http://searchstorage...ta-and-all-that

 

 

 

Original link I gave says the same thing.

 

Don't trust Wikipedia with everything. Network links are quoted in binary. If in doubt on Speedtest and other apps, change their reporting from kbps to mbps. You'll see that all of them figure 1024 kbps = 1 mbps. The only place of significance that uses the 1000 bits / kilobit (power of 10) is hard drives so they can sell you an inflated size.

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Don't trust Wikipedia with everything. Network links are quoted in binary. If in doubt on Speedtest and other apps, change their reporting from kbps to mbps. You'll see that all of them figure 1024 kbps = 1 mbps. The only place of significance that uses the 1000 bits / kilobit (power of 10) is hard drives so they can sell you an inflated size.

 

I like my inflated size hard drives, lol. At least my format size shows like what the box says. :lol:

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No, only hard drives use powers of 10. Network transfer speeds are definitely powers of 2.

 

Would it make you feel better if both of you are quasi correct?

 

Binary bit metrics follow base 2 logarithms. The base is 2, and the exponent is a multiple of 10 (e.g. kilo = 2^10, mega = 2^20, giga = 2^30, tera = 2^40).

 

AJ

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Don't trust Wikipedia with everything. Network links are quoted in binary. If in doubt on Speedtest and other apps, change their reporting from kbps to mbps. You'll see that all of them figure 1024 kbps = 1 mbps. The only place of significance that uses the 1000 bits / kilobit (power of 10) is hard drives so they can sell you an inflated size.

 

I posted 2 links saying the exact same thing. It is a standard.

 

Just did a speed test at Speedtest.net and it says in kbits down 30408. I have a 30Mbps line 30408/1000=30.408 Mbps. Changed it back to Mbps on their site and it says 30.41 (rounded off). So obviously they are dividing by 1000.

 

 

Would it make you feel better if both of you are quasi correct?

 

Binary bit metrics follow base 2 logarithms. The base is 2, and the exponent is a multiple of 10 (e.g. kilo = 2^10, mega = 2^20, giga = 2^30, tera = 2^40).

 

AJ

 

Not all bit metrics are exponents of 10: nybbles, words, double words, and even paragraphs. Bits and bytes are the more commonly referred to measurements.

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I posted 2 links saying the exact same thing. It is a standard.

 

Just did a speed test at Speedtest.net and it says in kbits down 30408. I have a 30Mbps line 30408/1000=30.408 Mbps. Changed it back to Mbps on their site and it says 30.41 (rounded off). So obviously they are dividing by 1000.

 

 

Check the weblinked png drawing-- you'll find it doesn't match what the screen shows-- app bug in some versions. Network rates are always given in 2^10 increments rather than the 1000 between.

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1911487907.png

 

 

 

 

 

What bug? Matches up just fine. I checked it in my history.

 

30989/1000=30.989. They just rounded to 2 decimal places for Mbps.

 

And per their site

 

By default, Speedtest.net measures your connection speed in mbps, meaning Megabits Per Second. Mbps is the ISP industry-standard, and we use it on Speedtest.net so you can easily compare your result to your broadband plan's speed.

 

However, we offer four different options on your settings page:

  • kbps or Kilobits Per Second - One kilobit is 1000 bits, and bits are the smallest possible unit of information (a little on/off switch). This was typically used by mobile connections, but as mobile carriers get faster they're switching over to megabits.
  • kBps or KiloBytes Per Second - Bytes are made up of eight bits, so one kilobyte equals eight kilobits. File-sizes on your computer are typically measured in bytes, so you'll usually see kilobytes used by download utilities. Bytes are capitalized when used in acronyms to distinguish them from bits, since both start with the letter B.
  • mbps or Megabits Per Second - The default, as we've already discussed. It takes 1000 kilobits to make a megabit.
  • mBps or MegaBytes Per Second - It takes eight megabits to make one megabyte. Most of the files on your computer are measured in megabytes, and if you have a fast connection you'll see this used in download utilities.

 

So where you are getting this 2^10 increment stuff is beyond me.

Edited by Sandman
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So where you are getting this 2^10 increment stuff is beyond me.

 

The 2^10 increment "stuff" is how the kernel network monitors actually count the bits at the software level. If they are now reporting wrong to artificially inflate the figures like the hard disk manufacturers started doing, "buyer beware". In the code, if you open a terminal emulator in android (or Linux) to look at the network interface status, it WILL count network transfers with kilobits as 1024 bits, etc. That's how computers work internally.

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For reference, Sprint tracks data usage in properly calculated kilobytes, megabytes, and gigabytes. See the Ts and Cs:

 

Data: Services are not available with all Sprint phones. The amount of data transmitted over our network is measured in kilobytes (KB), megabytes (MB) or gigabytes (GB). Unless specified otherwise. 1024KB equal 1MB. 1024MB equal 1GB.

 

AJ

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Yeah I write software and buffer size calculations are powers of 2. This makes sense when you realize there is usually a huge performance hit for "unaligned" memory access (hitting odd memory addresses not even multiples of the appropriate power of 2, eg: 4 bytes or 32 bits on a 32 bit system). So a 16K memory buffer should be 16 * 1024, not 16000.

 

The powers of 10 thing was invented by HDD manufacturers. I'm sorry to see others copying it. There has been a push to differentiate by using Xib suffixes to denote powers of two, eg 2MiB but so far hasn't caught on.

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The 2^10 increment "stuff" is how the kernel network monitors actually count the bits at the software level...In the code, if you open a terminal emulator in android (or Linux) to look at the network interface status, it WILL count network transfers with kilobits as 1024 bits, etc.

 

As they should since they have demodulated the signal received. Two different animals: modulated signal vs. demodulated signal.

 

 

That's how computers work internally.

 

I know how they work internally, usually better than some people. I use to dabble in x86 assembler back in the day, mainly 16bit. :)

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As they should since they have demodulated the signal received. Two different animals: modulated signal vs. demodulated signal.

 

 

 

 

I know how they work internally, usually better than some people. I use to dabble in x86 assembler back in the day, mainly 16bit. :)

 

Regardless of what you want to call it modulated or not, a kilobit (or kilobyte) as measured by Sprint or any ISP, is 1024 bits (or bytes) as noted above. And that is the proper unit of measure.... oh, and I did assembly and ML programming on 8-bit, 16-bit, and 32-bit processors.

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Wow the last thing I thought I would see on this site is guys getting onto a bit measuring contest.

 

Lets just all agree that regardless of how you measure your bits, there still not big enough.

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Regardless of what you want to call it modulated or not, a kilobit (or kilobyte) as measured by Sprint or any ISP, is 1024 bits (or bytes) as noted above. And that is the proper unit of measure.... oh, and I did assembly and ML programming on 8-bit, 16-bit, and 32-bit processors.

 

What Wiwavelength pointed out was how Sprint tracks data usage not how it measures data transmission.

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What Wiwavelength pointed out was how Sprint tracks data usage not how it measures data transmission.

 

Actually, the data transmission is modulated with CDMA, which means it is spread over 1.2288 mcps (far greater than the data rate). What they track is just as they state: 1KB = 1024 bytes, 1MB = 1024 KB, 1GB = 1024 MB. This is the data transmitted over the network. The same definition is used by AT&T U-verse, Verizon on their data plan usage widget, and Cox on their usage widget. As numerous people on this thread have tried to tell you, this is the proper (and billed) measurement for multiples of computer data. You're wrong.

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What Wiwavelength pointed out was how Sprint tracks data usage not how it measures data transmission.

 

Sure, for transmission, we have QPSK, which carries two bits per symbol, 8-PSK, which carries three bits per symbol, and 16-QAM, which carries four bits per symbol. Heck, with LTE now, we have 64-QAM, which carries six bits per symbol. But I fail to see how RF modulation is at all relevant to this discussion.

 

AJ

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Sure, for transmission, we have QPSK, which carries two bits per symbol, 8-PSK, which carries three bits per symbol, and 16-QAM, which carries four bits per symbol. Heck, with LTE now, we have 64-QAM, which carries six bits per symbol. But I fail to see how RF modulation is at all relevant to this discussion.

 

AJ

 

I agree-- and for the reverse link on EVDO Rev. A, we're limited to 8-PSK and 16-QAM on the forward link. The transmitted data far, far exceeds the amount actually processed and used in the device. I was merely pointing out that nitpicking the transmission rate versus the transmitted total is pointless. The ISP (Sprint in this case) like every other ISP I can think of uses the proper binary-based definition for network data transceived. I'm well aware of the IEC's introduction of the Mebi- and Kibi- SI prefixed in 2000 to try to "simplify" measurement of computer data; however, aside from hard drive manufacturers as pointed out in this thread, nobody uses this new "standard". The guy that is arguing is short-changing himself from Sprint's 300 megabyte per month data roaming limit anyway-- by my calculations, he would short-change himself by 14,572,800 bytes using his rather than Sprint's (and everyone else's) definition of KB, MB.

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I'm not trying to get this started again, I just happened upon this in another forum. From Sprint T&C:

 

The amount of data transmitted over our network is measured in kilobytes (KB), megabytes (MB) or gigabytes (GB). Unless specified otherwise 1024KB equals 1MB. 1024MB equal 1GB.[/Quote]

https://shop2.sprint.com/en/legal/os_general_terms_conditions_popup.shtml

 

Hope this helps clarify things.

 

Sent via Forum Runner on my redsn0w iOS 5.1 iPhone 4 

Edited by gopher_otis
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