1. RAM
Chapter 5

2. Understanding DRAM Organizing RAM Practical DRAM DRAM Sticks
64K x 1, 256K x 1 -> 8 bit
Practical DRAM
Intel 8088 had 1 byte frontside bus. Required two reads or writes.
Cost issues
DRAM Sticks
X4, x8, x16 memory chips
Single Inline Memory Module
Consumer RAM
Capacity organization’s most important concept

3. Types of RAM SDRAM – Synchronous Dynamic Random Access Memory
Synched to the system clock
DIMM
Mostly 64-bit
Banks of memory
RDRAM – Rambus DRAM
Dual channel architecture. Must be installed in pairs. MCC alternated between RIMMs
CRIMM – continuity RIMM
Proprietary. Expensive. Intel only.

4. Types of RAM DDR SDRAM – Double Data Rate SDRAM DDR2 DDR3
Read/write twice per clock cycle
Table 5-1
DDR2
Clock doubled I/O circuits
Cache on the module
Table 5-2
DDR3
Table 5-3
Doubles buffer size
Can overclock RAM
Triple-channel memory

5. Types of RAM DDR3L/DDR3U DDR4 Low voltage Higher densities
Lower voltages

6. RAM Variations Double-sided DIMM Latency Parity and ECC
Chips on both sides of the module
Physical space may be an issue
Latency
There is a time lag between when the MCC requests and the module returns data
There is a time lag between possible requests
CL2 or CL3 wait 2 or 3 clock cycles between actions
Parity and ECC
Stores extra bits to detect memory errors
Registered and Buffered Memory
A register is added to the module to act as a buffer between the module and the memory controller

7. Working with RAM Do you need more RAM? Getting the right RAM
Virtual Memory
Disk thrashing
Pagefile.sys
System RAM Recommendations
32-bit Windows: 2GB; 4 GB better
64-bit Windows: 4GB; 8GB better; 16+GB for processor intensive programs
Control Panel
ReadyBoost
Can use flash device as virtual memory
Getting the right RAM