1. CSE 102 Introduction to Computer Engineering
Unit Conversion

2. Clock Speed Clock cycle 1 Hz means 1cycle/second
1 cycle takes 1 second
1 MHz means 1million cycles/second (106 cycles/second)
1 cycle takes 1/106 seconds (1ms)
1 GHz = 1000 MHz
1 cycle

3. Time 1 hour = 60 minutes 1 minute = 60 seconds
1 second = 1000 milliseconds (ms)
1 millisecond = 1000 microseconds (ms)
1 microsecond = 1000 nanoseconds (ηs)

4. Capacity 1 byte = 8 bits 1 Kilobyte (KB) = 1000 bytes = 103 bytes
1 Megabyte (MB) = 1000 KB = 106 bytes
1 Gigabyte (GB) = 1000 MB = 109 bytes
1 Terabyte (TB) = 1000 GB = 1012 bytes
1 Petabyte (TB) = 1000 TB = 1015 bytes

5. Speed
Flop/s: is a unit that shows how many floating-point operations can be done in one second.
1 Mflop/s = flop/s
1 Gflop/s = 1000 Mflop/s
1 Tflop/s = 1000 Gflop/s
1 Pflop/s (Petaflop/s) = 1000 Tflop/s = 1015 flop/s

6. Example
A program having instructions is run on a 5MHz machine. Execution of an instruction takes 3 cycles. How long does it take to execute this program?
1 cycle takes: 1/(5x106) seconds = 0.2 ms
For one instruction: 3x0.2 = 0.6ms
For the program: x0.6 = ms
= 0.24 seconds