1. Subject: Computer Architecture & Organization
Topic: Random Access Memory (RAM)
Guided by:
Mrs. B. Padmavathi
Group No : 06
(SCOB48) Uttam Singh
2. Introduction
• RAM is a form of computer data storage which stores
frequently used program instructions to increase the
general speed of a system.
• It is a volatile and must faster memory .
• When the computer first starts a
program it sends an address to RAM,
automatically senses the data
corresponding to that address back
to the CPU, that data is then
processed by the CPU accordingly.
3. Types of RAM
Static Random Access Memory (S-RAM)
• No need to refresh hundreds of times in a second.
• Main purpose is to decrease the processing time.
• Very much faster than D-RAM, mostly used as cache
memory and as main memory in servers.
• Much more expensive, require more space &power.
Dynamic Random Access Memory (D-RAM).
• Value must be refreshed many time in a second.
• Main purpose is to decrease the processing cost.
• Most popular RAM and mostly use.
• Slower, Cheaper, easily available & require less power.
4. Type Name Max. Clock Rate Bandwidth
FPM Fast Page Mode 25MHz 200 MBps
EDO Extended Data
Output
40MHZ 320 MBps
SDRAM Synchronous
Dynamic RAM
133MHz 1.1 GBps
DDR1 SDRAM Double data rate 1
SDRAM
266MHZ (x2) 4.2 GBps
DDR2 SDRAM Double data rate 2
SDRAM
533MHz (x2) 8.5 GBps
DDR3 SDRAM Double data rate 3
SDRAM
800MHz (x2) 12.8 GBps
DDR4 SDRAM Double data rate 4
SDRAM
1600MHz (x2) 25.6 GBps
5.
6. Channels of RAM
• The channels permit reading from and writing to memory to occur
on distinct channels.
• More the channels more is the speed of reading and writing.
• Multi-channel memory architecture is a technology that increases
the data transfer rate between the DRAM memory.
Hinweis der Redaktion
RAM (Random Access Memory) is a type of memory that computers use to store data and softwares to which it needs to access quickly.
It is a volatile memory, that is, the information stored inside vanishes when the computer is turned off; although there are also RAM memories that do retain the information, for example, flash memories.
The stored data does not only vanish when the computer is turned off, but that is also must be eliminated when the file containing data is not being modified anymore.
The computer will work faster depending on the quantity of gigabytes (or megabytes) of RAM memory it has installed in it.
Working
When the computer first starts a program it sends an address to RAM to begin retrieving that program. The RAM address just consist a series of 1’s and 0’s representing ‘ON’ and ‘OFF’ wire.
RAM does not do anything with that address until the CPU turns on the “SET” or “ENABLE” wire. If the enable wire is turned ON the RAM automatically senses the data corresponding to that address back to the CPU, that data is then processed by the CPU accordingly.
FRM DRAM (Fast Page Mode Dynamic Random Access Memory):-It was the original form of DRAM. It waits through the entire process of locating a bit of data by column and row and then reading the bit before it starts on the next bit. Maximum transfer rate to L2 cache is approximately 176 Mbps.
EDO DRAM (Extended data-out Dynamic Random Access Memory) does not wait for all of the processing of the first bit before continuing to the next one. As soon as the address of the first bit is located, EDO DRAM begins looking for the next bit. It is about five percent faster than FPM. Maximum transfer rate to L2 cache is approximately 264 Mbps.
SDRAM is a type of dynamic random access memory which is synchronized with the clock speed that the microprocessor is optimized for. SDRAM is about five percent faster than EDO RAM and is the most common form in desktops today. Maximum transfer rate to L2 cache is approximately 528 Mbps.
DDR SDRAM: Double data rate synchronous dynamic RAM is just like SDRAM except that is has higher bandwidth, meaning greater speed. It is a newer variant of SDRAM. Maximum transfer rate to L2 cache is approximately 1,064 Mbps .
The system’s RAM (Random Access Memory) prevents the PC from achieving its maximum capable performance. This occurs because the processor (CPU) is faster than the RAM, and usually it has to wait for the RAM to deliver data. During this wait time the CPU is idle, doing nothing (that’s not entirely true, but it fits our explanation). In a perfect computer, the RAM would be as fast as the CPU. Dual-, triple-, and quad-channel are techniques used to double, triple, or quadruple the communication speed between the memory controller and the RAM, thus increasing the system performance. In this tutorial, we will explain everything you need to know about these technologies: how they work, how to set them up, how to calculate transfer speeds, and more.
