Computer Memory

Virtual memory, which is much less efficient than physical memory (RAM).

The computer contains:
Hard Drive
RAM (memory)
Processor chip
Graphic chip
Motherboard
mouse+ keyboard
Monitor/Screen


The main section would be the Motherboard and RAM. Computer would not be able to run without it.

Whenever anything is stored in the memory of your computer (RAM) it is stored at a specific place. Each specific place in your memory has its address that can be used to tell computer programs to go to those addresses to perform actions on the object stored at that address.

It is similar to how you have your house number.

DDR

dual ranked dimm. This is incorrect! Single-ranked DIMMs cost more but perform better because the controller accesses all chips at the same time. Dual and quad ranks are a method of reducing the overall price of memory in a system, but at the expense of performance.

You need 20 bits of address bus to address 1 Mb of memory.

"RAM" Random Access Memory.

Once the PC or MAC is rebooted or powered down, all memory stored in the RAM is dumped.

SD Ram is actually SDR SDRAM, and DD Ram is actually DDR SDRAM, though the former does not usually have the SDR in front of it. The letters SDR and DDR stand for Single Data Rate and Double Data Rate, and the letters SDRAM stand for Synchronous Dynamic Random Access Memory. The main difference between SDR and DDR memory is speed. There are a lot of little differences, but the main one (IMHO) that affects the user is speed: DDR can transfer data at roughly twice the speed of SDR. More speedy data rates = better performance. Just remember, the motherboard you are using must include the appropriate chipset to support the different RAM types. They are not interchangeable. SDR SDRAM comes in three main flavors: PC66, PC100 and PC133. Each successive number refers to the bus speed of the RAM in MHz, thus PC66 runs at 66 MHz, PC100 runs at 100 MHz, etc. SDR SDRAM has 168 pins at the connector.

DDR SDRAM has 184 pins at the connector, which is one reason you can't just use DDR instead of SDR, and comes in many different flavors; PC2100 which runs at 266 MHz, PC2700 which runs at 333 MHz, PC3200 which runs at 400 MHz, etc. While the numbers on SDR SDRAM referred to clock speeds, the DDR SDRAM numbers come from the theoretical maximum bandwidth in Megabytes per second (MB/s). Thus, PC2100 has a theoretical maximum bandwidth of 2100 MB/s, but runs at 133 MHz. DDR SDRAM modules are now available from PC1600 all the way up to PC4400, which has a bandwidth of 4400 MB/s and runs at 550 MHz. In order to know which type of RAM you need, you must know what your motherboard supports. I recommend searching the motherboard manufacturer's website for this info, or review sites like tomshardware.com or sharkyextreme.com. Good luck!

Yes they are definitely different as DDR stands for Double Data Ram & SDR stands for Single Data Ram and further explanation can be found here

http://en.wikipedia.org/wiki/DDR_SDRAM

RAM: Random Access Memory

duration of iconic memory for about less than one second whereas duration of Echoic memory for about Three to four second- Nilesh Gunjal ( M.A. Psychology)

Memory in a computer system is divided into segments. The logical size of these segments varies from system to system, and from operating system to operating system. Each of these segments is assigned a unique address, which is called a memory address.

Memory addresses are commonly represented in hexadecimal format on modern computer systems. Generally speaking, many recent 32-bit operating systems, such as Microsoft Windows XP, are able to assign 32-bit memory addresses, which is 2^32 unique addresses, or 4,294,967,295 different memory locations. Each memory address (also known as memory blocks) points to one byte of data (or storage space) within the memory system. Thus, most 32-bit operating systems utilizing 32-bit memory addressing are limited to 4GB of total memory, since memory capacity beyond this has no way to be assigned an address.

Newer 64-bit operating systems, such as Windows 7 x64, that use a 64-bit memory addressing scheme (2^64) are able to address up to 16 exabytes of memory. (Note that this is considered practically unlimited in the terms of current computer memory usages.)

Thus, when a program issues a command for the CPU to recover data or instructions from memory, the CPU will locate the correct data location using the memory address assigned to the requested data. In most modern operating systems, the actual physical assignment of data and / or instructions in memory is controlled by the operating system itself.

In order to take advantage of the Dual Channel option on your motherboard, you will need a matched pair of memory.

If you only install one stick of 512 MB memory, you will have to turn off the Dual Channel capabilities on your motherboard.

If you install a matched pair of 256 MB memory, you can keep Dual Channel enabled.

I would recommend buying at least 2x512 MB if not 2x1 GB of memory. Prices for 2x256 MB may be very expensive compared to 2x1 GB.

Magnetic disks offer faster access times compared to magnetic tape due to their random access nature, allowing for quicker data retrieval. Additionally, magnetic disks provide higher data transfer rates, making them more suitable for applications requiring rapid data processing. Furthermore, magnetic disks have a lower susceptibility to physical damage and data loss compared to magnetic tape, making them a more reliable storage medium for critical data.

There are 131,072 bytes in one megabite. In order to figure out how many bytes are in 25 megabites you need to multiply 131,072 by 25. Using this equasion you can figure out that 3,276,800 bytes are in 25 megabites.

No. Much, much more than that.

On average one movie is 2GB. That's two gigabytes.

A high definition (HD) movie would be around 3 or 4.5GB

Memory means the RAM of the CPU and when your computer is switched off you can't save any form of data in your memory (RAM). This is because RAM is a place in the CPU's system where data is stored temporarily and it gets removed as soon as you turn off your CPU. (RAM requires a constant voltage to retain information.) So by turning the PC off, all data in the RAM is lost.

A kilobyte (KB) is equal to 1,024 bytes. A megabyte (MB) is 1,024 kilobytes. So there are 1,024 KB * 256 = 262,144 KB in 256 MB

When a computer is first powered up it runs a "Power On Self Test" (POST). Many people call it a "POST test", but of course, that's redundant.

The POST runs through some basic systems, verifying that the computer is capable, at a very basic level, of running.

3 short beeps means that you have a problem with RAM.

RAM is VERY static sensitive. Your friend could have subjected the RAM to static electrical charges and not even known that he/she was doing it.

Remove the memory, put it in a static free container and take it to your local computer geek shop and have it tested. I'll include a link to a web site that lists the "Beep codes" and their meaning. http://www.computerhope.com/beep.htm

Operating system must be loaded first so that other applications and programs will be able to work.

1GB of DDR2 is definitely better. DDR3 is only a teeny tiny bit faster RAM. You'd barely

be able to tell in a benchmark test.

But to have double the amount, that's a huge difference.

DMA , IRQ and I/O address

DDR3 SDRAM stands for double data rate type three synchronous dynamic random access memory. It is used at the tempory memory a computer needs to operate. It is a faster version of the DDR2 RAM.