Monday, April 25, 2011

Your smartphone is very powerful!

It seems that most people, especially present day young ones, have problems understanding my Apollo 11 illustration.  I will try again with another example.

When the most well-known bank in my city had a million customers, it had 50+ branches.  Almost every customer operated a savings account where each was given a savings book.  Every deposit or withdrawal transaction was printed as a one-line entry in the book with the latest balance in the second last column.  (The last column was a comments field.)

Every teller in the branch had an IBM terminal.  Customers would fill up and sign a form to withdraw money, or just present cash to deposit.  The teller would open the savings book to the page where the last entry was and insert the book into the printer next to the terminal.  She would push the book all the way in.  When she hit the key to print, the central mainframe computer would send out the exact number of line-feeds so that the latest transaction would be printed nicely just below the previous one.

Overall it was a pretty efficient system.  It even took care of transactions not conducted at the branch, for example ATM withdrawals, by printing them in the savings book the next time you presented it at the branch.

The whole system was driven by two state-of-the-art IBM System 370 mainframes.  Each had 8MB of core RAM.  I can't remember the clock speed of the mainframe.  Probably it was below 5MHz, given that most register based S/360 opcodes took one cycle each and I thought the system had a couple of MIPS.  All the hardware in the branches were terminals, that is, every keystroke by each teller had to be sent to and processed by the IBM mainframe.

What the bank had is but a small fraction of what the phone in your hand has: 8MB vs 512MB, 5MHz vs 1,000MHz. To conclude, your stock iPhone alone is grossly over-powered to run the total operations of a bank with 50 branches and a million customers.  Do you get it?  It's not an analogy.  It's not an extrapolation.  It actually happened.  Imagine a 10,000 sq-foot computer room totally empty except for an iPhone sitting in the middle and driving all functions of the bank.

What's the catch?  There is none.

This illustration is not as beautiful as the Apollo 11 one as you can argue that now there're Internet banking requirements and banks now do more than just handle deposits and withdrawals.  So please go and read the Apollo story.  The distance to the moon has not increased, and astronauts are not asking for more comfortable seats.

What all this means is that we have tremendous power to do whatever we want.  It's like the (impossible) luxury of having unlimited electricity or water.  The availability of energy and water is worse now than at the beginning of the twentieth century, and is getting worse with each passing day.  On the other hand, we have more and more computing power at our disposal.  So, it's time to get off our butts and do something useful with all this power.

1 comment:

Wang Sun said...

Who needs a smartphone? My three and a half year old and one and a half G cell phone (it has got some GPRS thingy) is still serving me fine. And I still have my five and a half year old notebook, which is still going great guns (except for a HDD change last year).