Case Sensetivity in Speed Ratings? Yup, They Matter

You buy computer stuff.  Even if you hate it, it’s a part of your job.  Every manufacturer wants you to think their product is the best, so they’re constantly showing you the biggest number they can.  Bigger is better, right?  Sometimes.  (My girlfriend assures me it doesn’t matter.)

For the moment, consider these speed ratings:

  1. 60MB/s
  2. 100Mb/s
  3. 480Mb/s
  4. 9600 b/s

Which is the fastest?  The first thing to recognize is that the size of the “b” matters – a lot.  Like, to a factor of eight.  Each prefix multiplier is 1,000x it’s previous.  (The order is  single-bytes, Kilo, Mega, Giga, Tera, Peta, Exa, Zetta, Yotta.)  Let’s convert them all into the same units so we can compare actual speeds.  In order:

  1. 60MB/s
  2. 12.5MB/s
  3. 60MB/s
  4. 0.0012MB/s

I threw in 1 and 2 to trick you.  Look at number 4, whoa!  That was the speed of my first modem, and consequently my first internet connection.  Compared to today’s 20Mb/s line, this was the equivalent of 0.0096Mb/s.  Yikes!

Your broadband provider sells you service in bits per second (little b).  If they use a big B in their literature, they’re either mistaken or liars.  So if you have a 50 megabit internet connection, that’s considered quite fast, but how does it compare to a 400x CF card?  Take a look.

  • Internet: 50mb/s = 6.25MB/s
  • 400x CF card: 400 * 150KB/s = 60,000KB/s = 60MB/s

No contest.  That simple little CF card is nearly ten times faster.

The correct way to read these differences is xBytes/second or xbits/second.  Big B is bytes, little b is bits.  There are eight bits in a Byte, so when the b is little it’s important to recognize that it’s 1/8th the speed of something with a capital B in the same prefix multiplier.

Keep this in mind, and it will help you to decipher some of the smoke that marketing departments attempt to blow up your ass.  Have you been tricked by a manufacturer who tried to make their numbers look bigger than they really are?  Tell us in the comments!

Be cautious around both big B’s and little b’s when photographing flowers.  They both sting.

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