1. YouTube Tuesday

2. RAM

3. Overview In this chapter, you will learn how to
Identify the different types of RAM packaging
Explain the varieties of DRAM
Install RAM properly
Instructor Tip
When gaining attention and establishing common ground, ask questions such as, “What is RAM?” or “Who here has ever installed RAM?”
For a positive statement, tell the class, “In this lesson, we are going to learn how to recognize various forms of RAM, how it works, and how to install it properly.”

4. DRAM

5. Program Execution
Program code is copied from your hard disk into RAM before it is executed…

6. DRAM
DRAM (Dynamic Random Access Memory) is the most popular type of electronic memory
Special type of semiconductor that stores individual 1’s and 0’s using microscopic capacitors and transistors
Note: We tend to interchange the terms RAM and DRAM. Just be aware that DRAM is really a type of RAM. Most PCs use DRAM, so when we refer to the RAM we are usually talking about DRAM. When we refer to DRAM, we are talking about RAM.

7. Organizing DRAM
DRAM is considered as the standard RAM due to its low cost, high speed, and ability to store data in a relatively small package
The RAM stores programs and data in 8-bit (1-byte) chunks of memory
DRAM chips are always referenced with respect to their depth and width
1 Meg x 4
256 K x 1

8. Organizing DRAM The depth and width are measured in units of bits
They can only be differentiated using the information printed on the chip itself
The physical size and the internal organization of the chip are not directly correlated

9. RAM Sticks

10. DIMM (Dual Inline Memory Module)
The 168-pin DIMM is the most popular DRAM package in use today
Extra pins to handle functions such as buffering and ECC
144-pin SO-DIMMs (Small Outline) are used in laptops

11. SDRAM
SDRAM (Synchronous Dynamic Random Access RAM) are tied to the system clocks
Faster than DRAMs
Only available on DIMMs
Use clock speed instead of access speed
SDRAM is always a DIMM, but a DIMM isn’t always SDRAM
What makes SDRAM faster?
Before SDRAM the system had to send the signal to DRAM, wait a certain number of clicks (this number was rounded up just to be sure the data would be ready), and then access the RAM for the data. Using the system clock, the chipset now knows exactly when the data is ready – speeding up the process

12. RDRAM RDRAM (Rambus DRAM) is a new type of RAM Speeds of up to 800 MHz
Comes on sticks called RIMMs
184-pin for desktops and 160-pin SO-RIMM for laptops
Terminology
RDRAM, or Rambus DRAM, is also called RIMM sticks.
RDRAM speeds start with “PC” followed by the speed, so 800 MHz RDRAM is known as PC800 and 1066 MHz RDRAM is known as PC1066.

13. DDR SDRAM (Double Data Rate)
DDR SDRAM (Double Data Rate SDRAM) doubles the throughput of SDRAM
184-pin DIMM packages
Speed of 200 or 266 MH.
Used in lower-end systems

14. Dual-Channel Architecture
Dual-channel architectures use two sticks of RAM together to increase throughput
Double-sided SIMMs/DIMMs
Double-side sticks have chips on both sides
DUAL DDR has a few quirks such as this one:
Motherboards that use NVIDIA’s nForce2 chipset have three DDR SDRAM slots, but dual channel only works if you populate the two blue dual slots and leave the third black slot empty
While every PC uses DRAM in one of its many variations for their RAM, other forms of RAM are found in PCs with names like VRAM and SGRAM.

15. Do You Need RAM? Two symptoms point to needing more RAM
General system sluggishness
Disk thrashing or excessive hard drive accessing
How do know if your disk is thrashing?
Observe the LED at work
Use FreeMeter (

16. Installing DIMMs Swing the side tabs away from upright
Push the DIMM down somewhat hard – the two tabs should move back into place
Tech Tip
Mixing PC100 and PC133
Although in theory it should work to add a PC133 stick to a system running at 100 MHz that already has a stick or two of PC100, such a move can greatly destabilize a PC. The frustrating part about this is that mixing destabilizes some systems, but not others. Worse, it doesn’t seem to matter which chipset or processor type the systems have. A motherboard from one manufacturer supporting a Pentium III with a VIA chipset will have no problems, for example, but a motherboard from another manufacturer with an identical chipset and CPU combination will crash from here to Tuesday. About the best advice I can offer is don’t mix at all and thus avoid all the fuss.

17. Check the RAM
A halt before the RAM check could indicate improperly installed RAM