1. The Triplets – ROM & RAM & Cache
Primary Storage
The Triplets – ROM & RAM & Cache

2. Intro
History
Travel
Cache
ROM
RAM

3. History Vacuum Tube Transistor SRAM – Static RAM DRAM – Dynamic RAM
1-bit per cell
No refresh - fast
DRAM – Dynamic RAM
More compact
Need refresh – slows speed

4. History
Vacuum Tubes to Transitors
Original Memory modules

5. History SDR SDRAM – Now obsolete PC 100 & PC-133
Computes on 16Bit per clock cycle

6. History
DDR - Old
Double clock speed
100, 133, 166 and 200 MHz

7. History DDR2 – Still Used Double clock speed;about 2-5% gain over DDR
400, 533, 667, 800, & 1066 MHz

8. History DDR3 – 2008 and beyond More Speed
1066, 1333, 1600, 1800, & 2000 MHz

9. History SIMM DIMM Single In-Line Memory Module
30-pin
72-pin
DIMM
Dual In-Line Memory Module
72-pin to 288-pin
DDR – DDR4

10. Travel

11. Cache On CPU Different from registers FAST!!!! Expensive Limited space
Between 5% and 100% of CPU speed
Expensive
Limited space
Different from registers
Not connected to CU or A/LU

12. ROM
Boot
Constant instructions

13. RAM Main memory Slower than cache Cheaper than cache Easy to expand
Approx 1% of CPU speed
Cheaper than cache
Easy to expand
CPU can change
Addressed