#How Stuff Works Feature Articles HowStuffWorks ICRA labels Video Center Maps Consumer Guide: * Auto Reviews | * Product Reviews * Make HSW your homepage | * Get Newsletter | * RSS | * Random Article Random Article HowStuffWorks Search HowStuffWorks and the web ____________________ Search A Discovery Company * Home * * Adventure * * Animals * * Auto * * Communication * * Computer * * Electronics * * Entertainment * * Food * * Geography * * Health * * History * * Home & Garden * * Money * * People * * Science * Computer Hardware * * Computer Peripherals * * Computer Security * * Computer Software * * Internet * Home > * Computer > * Computer Hardware > * Memory Next Page How RAM Works by Jeff Tyson and Dave Coustan * Print Email Cite Feedback Share * Digg This * Yahoo! Buzz * StumbleUpon * del.icio.us * Reddit Cite This! Close [icon_close.gif] Please copy/paste the following text to properly cite this HowStuffWorks article: Tyson, Jeff, and Dave Coustan. "How RAM Works." 25 August 2000. HowStuffWorks.com. 02 January 2009. Inside this Article 1. Introduction to How RAM Works 2. Memory Cells and DRAM 3. Static RAM 4. Types of RAM 5. Memory Modules 6. How Much RAM Do You Need? 7. See more » 7. How to Install RAM 8. Lots More Information 9. See all Memory articles How to Install RAM to a Desktop Computer How to Install RAM to a Desktop Computer Play Video * More Computer Videos » Computer Hardware Image Gallery RAM RAM is the best known form of computer memory and easy to upgrade. See more computer hardware pictures. Random access memory (RAM) is the best known form of computer memory. RAM is considered "random access" because you can access any memory cell directly if you know the row and column that intersect at that cell. The opposite of RAM is serial access memory (SAM). SAM stores data as a series of memory cells that can only be accessed sequentially (like a cassette tape). If the data is not in the current location, each memory cell is checked until the needed data is found. SAM works very well for memory buffers, where the data is normally stored in the order in which it will be used (a good example is the texture buffer memory on a video card). RAM data, on the other hand, can be accessed in any order. Similar to a microprocessor, a memory chip is an integrated circuit (IC) made of millions of transistors and capacitors. In the most common form of computer memory, dynamic random access memory (DRAM), a transistor and a capacitor are paired to create a memory cell, which represents a single bit of data. The capacitor holds the bit of information -- a 0 or a 1 (see How Bits and Bytes Work for information on bits). The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state. Power Up with RAM * RAM Quiz * Static vs. Dynamic RAM * Does adding RAM make your computer faster? A capacitor is like a small bucket that is able to store electrons. To store a 1 in the memory cell, the bu Save Changes cket is filled with electrons. To store a 0, it is emptied. The problem with the capacitor's bucket is that it has a leak. In a matter of a few milliseconds a full bucket becomes empty. Therefore, for dynamic memory to work, either the CPU or the memory controller has to come along and recharge all of the capacitors holding a 1 before they discharge. To do this, the memory controller reads the memory and then writes it right back. This refresh operation happens automatically thousands of times per second.­ Your browser does not support JavaScript or it is disabled. The capacitor in a dynamic RAM memory cell is like a leaky bucket. It needs to be refreshed periodically or it will discharge to 0. This refresh operation is where dynamic RAM gets its name. Dynamic RAM has to be dynamically refreshed all of the time or it forgets what it is holding. The downside of all of this refreshing is that it takes time and slows down the memory. In this article, you'll learn all about what RAM is, what kind you should buy and how to install it. See the next page to learn more about dynamic RAM and memory cells.­ Next Page Inside this Article 1. Introduction to How RAM Works 2. Memory Cells and DRAM 3. Static RAM 4. Types of RAM 5. Memory Modules 6. How Much RAM Do You Need? 7. How to Install RAM 8. Lots More Information 9. See all Memory articles * digg more * Yahoo! Buzz buzz more * Related Ad Categories Related Ad Links Related Content Explanations How Computer Memory Works How ROM Works How Flash Memory Works Expert Reviews Desktop Computer Reviews Laptop Reviews Prices: Ram [34528162-100x100-0-0.jpg] Hewlett Packard SDRAM 2 GB (397411B21) 2 x 1 GB, ECC Fully Buffered DDR RAM, 667 MHz, FB-DIMM, 2 Modules $80 - $215 See It [36820457-100x100-0-0.jpg] Hewlett Packard 2 2 GB DDR RAM (408853B21) 2 x 1 GB, Registered DDR RAM, 667 MHz, DIMM 240-pin, 2 Modules $144 - $398 See It [43024582-100x100-0-0.jpg] Kingston 2 GB PC2100 DDR RAM (KTS76022G) 2 x 1 GB, Registered PC2100 DDR RAM, 266 MHz, DIMM 184-pin, 2 Modules $528 - $758 See It Search HowStuffWorks and the web ____________________ Search * Home| * Adventure| * Animals| * Auto| * Communication| * Computer| * Electronics| * Entertainment| * Food| * Geography| * Health| * History| * Home & Garden| * Money| * People| * Science * Company Info | * Advertise With Us | * Newsletter | * Careers | * Privacy | * Contact Us | * Help | * Visitor Agreement | * RSS * HowStuffWorks | * HSW Brazil | * HSW China HowStuffWorks China © 1998-2009 HowStuffWorks, Inc. * Discovery Communications, LLC | * Discovery Channel | * TLC | * Animal Planet | * Discovery Health | * Science Channel | * Planet Green | * Discovery Kids * Petfinder | * TreeHugger | * Military Channel | * Investigation Discovery | * HD Theater | * FitTV | * Turbo * ATTENTION! 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