RAM" redirects here. For other uses of the acronym, see Ram.
A four-megabyte RAM card for the VAX 8600 computer (circa 1986). The RAM chips are located in the rectangular areas to the left and right.Random-access memory (usually known by its acronym, RAM) refers to data storage formats and equipment that allow the stored data to be accessed in any order — that is, at random, not just in sequence. In contrast, other types of memory devices (such as magnetic tapes, disks, and drums) can access data on the storage medium only in a predetermined order due to constraints in their mechanical design.
Generally, RAM in a computer is considered main memory (or primary storage): the working area used for displaying and manipulating data. This type of RAM is usually in the form of integrated circuits (IC). These are commonly called memory sticks or RAM sticks because they are manufactured as small circuit boards with plastic packaging and are about the size of a few sticks of gum. Most personal computers have slots for adding and replacing memory chips.
RAM is typically erased when a computer is shut down, though some RAM chips maintain data indefinitely without electrical power. Technically, RAM devices are not limited to memory chips, and random-access memory as a storage format is not limited to use as working memory. In a broad sense, modern storage devices for long-term or secondary storage, including magnetic media and laser-readable CDs and DVDs, are forms of random-access memory.
Look up RAM, random access memory in Wiktionary, the free dictionary.Most RAM can be both written to and read from, so "RAM" is often used interchangeably with "read-write memory." In this sense, RAM is the opposite of Sequential Access Memory.
Contents [hide]
1 Overview
2 The Memory Wall
3 Shadow RAM
4 RAM packaging
4.1 General RAM packaging formats
4.2 Common RAM modules
4.3 History of RAM modules used in PCs
5 RAM manufacturers
6 See also
7 External links
[edit]
Overview
Computers use RAM to hold the program code and data during computation. A defining characteristic of RAM is that all memory locations can be accessed at almost the same speed. Most other technologies have inherent delays for reading a particular bit or byte. Adding more RAM is an easy way to increase system performance.
Early main memory systems built from vacuum tubes behaved much like modern RAM, except that they failed frequently. Core memory, which used wires attached to small ferrite electromagnetic cores, also had roughly equal access time. The term “core” is still used by some programmers to describe the RAM main memory of a computer. The basic concepts of tube and core memory are used in modern RAM implemented with integrated circuits.
Samsung 512 MiB DDR-SDRAM module on motherboard.
Alternative primary storage mechanisms usually involved a non-uniform delay for memory access. Delay line memory used a sequence of sound wave pulses in mercury-filled tubes to hold a series of bits. Drum memory acted much like the modern hard disk, storing data magnetically in continuous circular bands. (See primary storage for a greater discussion of these alternatives and others.)
Many types of RAM are volatile, which means that unlike some other forms of computer storage such as disk storage and tape storage, they lose all data when the computer is powered down. Modern RAM generally stores a bit of data as either a charge in a capacitor, as in dynamic RAM, or the state of a flip-flop, as in static RAM.
Currently, there are several types of non-volatile RAM under development, which will preserve data while powered down. The technologies used include carbon nanotubes and magnetic tunnel effect.
In summer 2003, a 128 KB Magnetic RAM chip was introduced, which was manufactured with 0.18 µm technology. The core technology of MRAM is based on the magnetic tunnel effect. In June of 2004, Infineon Technologies unveiled a 16 MB prototype based on 0.18 µm technology once again.
As for carbon nanotube memory, a high-tech startup Nantero built a functioning prototype 10 GB array in 2004.
Software can "partition" a portion of a computer's RAM, allowing it to act as a much-faster hard drive, which is referred to as a RAM disk. Unless the memory used is non-volatile, a RAM disk does not maintain the stored data if the computer is shut down.
Some types of RAM can detect or correct random unintentional faults called memory errors in the stored data (see RAM parity).
[edit]
The Memory Wall
The term "memory wall", first officially coined in Hitting the Memory Wall: Implications of the Obvious (PDF), refers to the growing disparity between CPU and memory speed. From 1986 to 2000, CPU speed improved at an annual rate of 55% while memory speed only improved at 10%. Given these trends, it was expected that memory latency would become an overwhelming bottleneck in computer performance.
Currently, CPU speed improvements have slowed significantly partly due to major physical barriers and partly because we have already hit the memory wall in some sense. Intel summarized these causes in their Platform 2015 documentation (PDF): "First of all, as chip geometries shrink and clock frequencies rise, the transistor leakage current increases, leading to excess power consumption and heat (more on power consumption below). Intel's new Tri-Gate could solve this problem. Secondly, the advantages of higher clock speeds are in part negated by memory latency, since memory access times have not been able to keep pace with increasing clock frequencies. Third, for certain applications, traditional serial architectures are becoming less efficient as processors get faster (due to the so-called Von Neumann bottleneck), further undercutting any gains that frequency increases might otherwise buy. In addition, resistance-capacitance (RC) delays in signal transmission are growing as feature sizes shrink, imposing an additional bottleneck that frequency increases don't address."
The RC delays in signal transmission were also noted in Clock Rate versus IPC: The End of the Road for Conventional Microarchitectures which projects a maximum of 12.5% average annual CPU performance improvement between 2000 and 2014. The data on Intel Processors clearly shows a slowdown in performance improvements in recent processors. However Intel's new processors, Core 2 (codenamed Conroe) shows a significant improvement over previous Pentium 4 processors.
[edit]
Shadow RAM
Shadow RAM is RAM whose contents are copied from read-only memory (ROM) to allow shorter access times [1], as ROM is in general slower than RAM. The original ROM is disabled and the new location on the RAM is write-protected. This process is called shadowing.
This section is a stub. You can help by adding to it.
[edit]
RAM packaging
Common RAM packages[edit]
General RAM packaging formats
Semiconductor RAM is produced as integrated circuits (ICs) or commonly RAM chips. RAM chips (ICs) are often assembled into plug-in modules. Some standard module types are:
RAM chip (Integrated Circuit or IC)
Dual in-line Package (DIP)
RAM (memory) modules
Single In-line Pin Package (SIPP)
Single in-line memory module (SIMM)
Dual in-line memory module (DIMM)
Rambus modules are technically DIMMs, but are usually referred to as RIMMs due to their proprietary slot.
Small outline DIMM (SO-DIMM). Smaller version of the DIMM, used in laptops. Comes in versions with:
72 pins (32-bit)
144 pins (64-bit)
200 pins (72-bit)
Small outline RIMM (SO-RIMM). Smaller version of the RIMM, used in laptops.
Stacked v. non-stacked RAM modules
Stacked RAM chips use two RAM wafers that are stacked on top of each other. This allows large module (like a 512mb or 1Gig SO-DIMM) to be manufactured using cheaper low density wafers. Stacked chip modules draw more power.
[edit]
Common RAM modules
Common RAM packages as illustrated to the right, from top to bottom:
DIP 16-pin (RAM chip, usually pre-FPRAM)
SIPP (usually FPRAM)
SIMM 30-pin (usually FPRAM)
SIMM 72-pin (so-called "PS/2 SIMM", usually EDO RAM)
DIMM 168-pin (SDRAM)
DIMM 184-pin (DDR SDRAM)
DIMM 240-pin (DDR2 SDRAM)
[edit]
History of RAM modules used in PCs
This section is a stub. You can help by adding to it.
[edit]
RAM manufacturers
Major manufacturers of semiconductor RAM as of 2006:
Company name Website
Corsair Memory http://www.corsairmemory.com/
Crucial Technology http://www.crucial.com/
EDGE Memory http://www.edgememory.com/
GEIL http://www.geilusa.com/
G.Skill http://www.gskill.com/
Hynix http://www.hynix.com/
Infineon Technologies now http://www.qimonda.com/
Kingston Technology http://www.kingston.com/
Legend http://www.legendmemory.com/
Micron Technology http://www.micron.com/
Mushkin http://www.mushkin.com/
OCZ Technology http://www.ocztechnology.com
Samsung http://www.samsung.com/
SimpleTech http://www.simpletech.com/
Ultra Products http://www.ultraproducts.com/
[edit]
See also
Registered/Buffered memory
Compact Flash
PCMCIA
Static RAM (SRAM)
Non-Volatile RAM (NVRAM)
Dynamic RAM (DRAM)
Fast Page Mode DRAM
EDO RAM or Extended Data Out DRAM
XDR DRAM
SDRAM or Synchronous DRAM
DDR SDRAM or Double Data Rate Synchronous DRAM; now being replaced by DDR2 SDRAM
RDRAM or Rambus DRAM
[edit]
External links
A definition of RAM – From searchMobileComputing.com
What kind of RAM do I have? – From Darrell's Computer Help and Information
"How RAM Works" – Article by Jeff Tyson and Dave Coustan
Memory Basics (Flash) – From RAM
How to Install PC Memory Guides
Memory Installation FAQ's
Ultimate Memory Guide – From Kingston
Retrieved from "http://en.wikipedia.org/wiki/Random_access_memory"
RAM" redirects here. For other uses of the acronym, see Ram.
A four-megabyte RAM card for the VAX 8600 computer (circa 1986). The RAM chips are located in the rectangular areas to the left and right.Random-access memory (usually known by its acronym, RAM) refers to data storage formats and equipment that allow the stored data to be accessed in any order — that is, at random, not just in sequence. In contrast, other types of memory devices (such as magnetic tapes, disks, and drums) can access data on the storage medium only in a predetermined order due to constraints in their mechanical design.
Generally, RAM in a computer is considered main memory (or primary storage): the working area used for displaying and manipulating data. This type of RAM is usually in the form of integrated circuits (IC). These are commonly called memory sticks or RAM sticks because they are manufactured as small circuit boards with plastic packaging and are about the size of a few sticks of gum. Most personal computers have slots for adding and replacing memory chips.
RAM is typically erased when a computer is shut down, though some RAM chips maintain data indefinitely without electrical power. Technically, RAM devices are not limited to memory chips, and random-access memory as a storage format is not limited to use as working memory. In a broad sense, modern storage devices for long-term or secondary storage, including magnetic media and laser-readable CDs and DVDs, are forms of random-access memory.
Look up RAM, random access memory in Wiktionary, the free dictionary.Most RAM can be both written to and read from, so "RAM" is often used interchangeably with "read-write memory." In this sense, RAM is the opposite of Sequential Access Memory.
Contents [hide]
1 Overview
2 The Memory Wall
3 Shadow RAM
4 RAM packaging
4.1 General RAM packaging formats
4.2 Common RAM modules
4.3 History of RAM modules used in PCs
5 RAM manufacturers
6 See also
7 External links
[edit]
Overview
Computers use RAM to hold the program code and data during computation. A defining characteristic of RAM is that all memory locations can be accessed at almost the same speed. Most other technologies have inherent delays for reading a particular bit or byte. Adding more RAM is an easy way to increase system performance.
Early main memory systems built from vacuum tubes behaved much like modern RAM, except that they failed frequently. Core memory, which used wires attached to small ferrite electromagnetic cores, also had roughly equal access time. The term “core” is still used by some programmers to describe the RAM main memory of a computer. The basic concepts of tube and core memory are used in modern RAM implemented with integrated circuits.
Samsung 512 MiB DDR-SDRAM module on motherboard.
Alternative primary storage mechanisms usually involved a non-uniform delay for memory access. Delay line memory used a sequence of sound wave pulses in mercury-filled tubes to hold a series of bits. Drum memory acted much like the modern hard disk, storing data magnetically in continuous circular bands. (See primary storage for a greater discussion of these alternatives and others.)
Many types of RAM are volatile, which means that unlike some other forms of computer storage such as disk storage and tape storage, they lose all data when the computer is powered down. Modern RAM generally stores a bit of data as either a charge in a capacitor, as in dynamic RAM, or the state of a flip-flop, as in static RAM.
Currently, there are several types of non-volatile RAM under development, which will preserve data while powered down. The technologies used include carbon nanotubes and magnetic tunnel effect.
In summer 2003, a 128 KB Magnetic RAM chip was introduced, which was manufactured with 0.18 µm technology. The core technology of MRAM is based on the magnetic tunnel effect. In June of 2004, Infineon Technologies unveiled a 16 MB prototype based on 0.18 µm technology once again.
As for carbon nanotube memory, a high-tech startup Nantero built a functioning prototype 10 GB array in 2004.
Software can "partition" a portion of a computer's RAM, allowing it to act as a much-faster hard drive, which is referred to as a RAM disk. Unless the memory used is non-volatile, a RAM disk does not maintain the stored data if the computer is shut down.
Some types of RAM can detect or correct random unintentional faults called memory errors in the stored data (see RAM parity).
[edit]
The Memory Wall
The term "memory wall", first officially coined in Hitting the Memory Wall: Implications of the Obvious (PDF), refers to the growing disparity between CPU and memory speed. From 1986 to 2000, CPU speed improved at an annual rate of 55% while memory speed only improved at 10%. Given these trends, it was expected that memory latency would become an overwhelming bottleneck in computer performance.
Currently, CPU speed improvements have slowed significantly partly due to major physical barriers and partly because we have already hit the memory wall in some sense. Intel summarized these causes in their Platform 2015 documentation (PDF): "First of all, as chip geometries shrink and clock frequencies rise, the transistor leakage current increases, leading to excess power consumption and heat (more on power consumption below). Intel's new Tri-Gate could solve this problem. Secondly, the advantages of higher clock speeds are in part negated by memory latency, since memory access times have not been able to keep pace with increasing clock frequencies. Third, for certain applications, traditional serial architectures are becoming less efficient as processors get faster (due to the so-called Von Neumann bottleneck), further undercutting any gains that frequency increases might otherwise buy. In addition, resistance-capacitance (RC) delays in signal transmission are growing as feature sizes shrink, imposing an additional bottleneck that frequency increases don't address."
The RC delays in signal transmission were also noted in Clock Rate versus IPC: The End of the Road for Conventional Microarchitectures which projects a maximum of 12.5% average annual CPU performance improvement between 2000 and 2014. The data on Intel Processors clearly shows a slowdown in performance improvements in recent processors. However Intel's new processors, Core 2 (codenamed Conroe) shows a significant improvement over previous Pentium 4 processors.
[edit]
Shadow RAM
Shadow RAM is RAM whose contents are copied from read-only memory (ROM) to allow shorter access times [1], as ROM is in general slower than RAM. The original ROM is disabled and the new location on the RAM is write-protected. This process is called shadowing.
This section is a stub. You can help by adding to it.
[edit]
RAM packaging
Common RAM packages[edit]
General RAM packaging formats
Semiconductor RAM is produced as integrated circuits (ICs) or commonly RAM chips. RAM chips (ICs) are often assembled into plug-in modules. Some standard module types are:
RAM chip (Integrated Circuit or IC)
Dual in-line Package (DIP)
RAM (memory) modules
Single In-line Pin Package (SIPP)
Single in-line memory module (SIMM)
Dual in-line memory module (DIMM)
Rambus modules are technically DIMMs, but are usually referred to as RIMMs due to their proprietary slot.
Small outline DIMM (SO-DIMM). Smaller version of the DIMM, used in laptops. Comes in versions with:
72 pins (32-bit)
144 pins (64-bit)
200 pins (72-bit)
Small outline RIMM (SO-RIMM). Smaller version of the RIMM, used in laptops.
Stacked v. non-stacked RAM modules
Stacked RAM chips use two RAM wafers that are stacked on top of each other. This allows large module (like a 512mb or 1Gig SO-DIMM) to be manufactured using cheaper low density wafers. Stacked chip modules draw more power.
[edit]
Common RAM modules
Common RAM packages as illustrated to the right, from top to bottom:
DIP 16-pin (RAM chip, usually pre-FPRAM)
SIPP (usually FPRAM)
SIMM 30-pin (usually FPRAM)
SIMM 72-pin (so-called "PS/2 SIMM", usually EDO RAM)
DIMM 168-pin (SDRAM)
DIMM 184-pin (DDR SDRAM)
DIMM 240-pin (DDR2 SDRAM)
[edit]
History of RAM modules used in PCs
This section is a stub. You can help by adding to it.
[edit]
RAM manufacturers
Major manufacturers of semiconductor RAM as of 2006:
Company name Website
Corsair Memory http://www.corsairmemory.com/
Crucial Technology http://www.crucial.com/
EDGE Memory http://www.edgememory.com/
GEIL http://www.geilusa.com/
G.Skill http://www.gskill.com/
Hynix http://www.hynix.com/
Infineon Technologies now http://www.qimonda.com/
Kingston Technology http://www.kingston.com/
Legend http://www.legendmemory.com/
Micron Technology http://www.micron.com/
Mushkin http://www.mushkin.com/
OCZ Technology http://www.ocztechnology.com
Samsung http://www.samsung.com/
SimpleTech http://www.simpletech.com/
Ultra Products http://www.ultraproducts.com/
[edit]
See also
Registered/Buffered memory
Compact Flash
PCMCIA
Static RAM (SRAM)
Non-Volatile RAM (NVRAM)
Dynamic RAM (DRAM)
Fast Page Mode DRAM
EDO RAM or Extended Data Out DRAM
XDR DRAM
SDRAM or Synchronous DRAM
DDR SDRAM or Double Data Rate Synchronous DRAM; now being replaced by DDR2 SDRAM
RDRAM or Rambus DRAM
[edit]
External links
A definition of RAM – From searchMobileComputing.com
What kind of RAM do I have? – From Darrell's Computer Help and Information
"How RAM Works" – Article by Jeff Tyson and Dave Coustan
Memory Basics (Flash) – From RAM
How to Install PC Memory Guides
Memory Installation FAQ's
Ultimate Memory Guide – From Kingston
Retrieved from "http://en.wikipedia.org/wiki/Random_access_memory"
Stands for "Random Access Memory," and is pronounced like the male sheep. RAM is made up of small memory chips that are connected to the motherboard of your computer. Every time you open a program, it gets loaded from the hard drive into the RAM. This is because reading data from the RAM is much faster than reading data from the hard drive.
Running programs from the RAM of the computer allows them to function without any lag time. The more RAM your computer has, the more data can be loaded from the hard drive into the RAM, which can help speed up your computer. In fact, adding RAM can be more beneficial to your computer's performance than upgrading the CPU
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Langa Letter: Speed And Security Via A RAM Drive
While it's not a panacea, judicious use of a RAM drive can make your PC faster and safer, Fred Langa says.
By Fred Langa
InformationWeek
Jan 31, 2005 12:00 AM
It was one of those small questions that opens up a huge topic:
Fred: Can you help me in my quest to learn how to load and run programs in a RAM drive using Win2000/XP?
-- Chas. Preston
It's an intriguing idea because some RAM operations are literally about a million times faster (that's six orders of magnitude) than a hard drive's. Therefore, any operations you can keep in RAM will typically complete much, much faster than those that involve reads/writes using a mechanical hard drive.
But (you knew there had to be a "but," right?) there's more to this than may meet the eye. You see, setting up and using a RAM drive for the wrong reasons can have the opposite effect--it can actually make your system slower. So before we get to the how-to, let's work through the strengths and weaknesses of RAM drives, so you can understand and avoid the bad outcomes.
What's a RAM Drive?
A "RAM drive" (also called a "RAM disk") is a section of your normal system RAM that's set aside and controlled by special software to emulate a standard hard drive: The software fools the operating system into thinking it's dealing with an ordinary physical hard drive that operates in a completely normal fashion, except that it's extremely fast.
Just as with any other drive, a RAM drive must be formatted before it can be used (although some RAM drive software does this for you automatically). Once in operation, a RAM drive can be written to or read from using all the normal file commands. As far as your PC knows, the RAM drive is just another normal storage device. But you'll see the difference in literally lightning-fast operation: A Format command, for example, may complete in a flash instead of slogging along for many minutes; copying a file may seem to be almost instantaneous.
What's A RAM Drive Best For?
Any software that's "disk intensive," with many read/write operations to a hard drive, can benefit enormously from using a RAM drive for temporary, working data storage. This can include large databases, large spreadsheets, and large word-processing documents, especially if the work you're doing involves many sorts, searches, finds/replaces, merges or similar operations. In fact, if any work you're doing requires moving or digging through large amounts of data, a RAM drive may really help speed things up.
Conversely, software that's not disk-intensive will gain little or no benefit from using a RAM drive. While you may gain some modest operational speed while things are running, your net benefit is likely to be small because of the time you'll lose setting up the RAM drive and copying the files you want to work on into the RAM drive.
Shutdowns take longer, too, because RAM drives are only good for temporary storage. Information in RAM is said to be "volatile:" When a PC shuts down, all the information in RAM--including any RAM drives--goes away. Unless you've copied the data out of the RAM drive to a real hard drive or backed it up to some other non-volatile media, you'll lose everything that was in RAM. This means that shutdowns have to take longer when you're using a RAM drive because you have to allow for extra steps to preserve the data stored there prior to killing the power or rebooting.
Thus, for non-disk-intensive operations, whatever time savings you may gain from the RAM drive will probably be negated by the time and hassle required to get things properly set up and shut down.
Because of this, a RAM drive isn't a panacea for slow disk accesses: It really helps in some very specific circumstances, mostly involving the manipulation of large files, or large numbers of files.
"Running Programs In RAM?"
Win2K and XP do a pretty good job of keeping actively used and needed data in normal system RAM; and the more RAM you give these systems, the more code and data they'll be able to keep there, ready for near-instant access. But when you assign system RAM to a RAM disk, that RAM is no longer available for general system use.
As the system tries to cope with the lowered amount of RAM, it may have to rely more on the pagefile/swapfile of the virtual memory system on the hard drive, which operates much, much more slowly than RAM. (Anything the operating system can't fit in RAM, it writes to the virtual memory pagefile/swapfile on the hard drive.)
Thus, adding a RAM disk may speed up disk-intensive file operations, but may actually slow down your system overall because there'll be less RAM available for running your programs. This goes to the heart of Charles Preston's question: "...how to load and run programs in...RAM." Given sufficient RAM, Win2K and XP will actually do just that on their own, running the program in system RAM as much as possible.
So, if (like Charles) your interest is making sure your programs run in RAM as much as possible, a RAM drive is not--repeat, not--the answer. Instead, add more RAM to the system as a whole. (For a fuller discussion of how Windows uses RAM, "memory optimizers," and how much RAM is enough, see this item as well as this one.
But if speeding up disk/file operations is your goal, than a RAM drive may help a lot, provided you have enough RAM to start with so you won't be short-changing the system as a whole. That's what we'll look at next.
RAM Tradeoffs
The more RAM you have, the more you can assign to a RAM disk without incurring overall performance losses from extra swapfile activity. Or, to put this the other way, the less RAM you have to start with, the smaller a RAM disk you'll be able to support without affecting performance.
If your system is toward the lower end of the recommended RAM amounts for your version of Windows (e.g. 128 Mbytes for XP), then you should either avoid RAM disk use altogether, or use only very small RAM disks--a few megs at most. Anything more, and you may start to cut into the RAM requirements of the system as a whole.
On the other hand, if you have abundant RAM, you can create more sizeable RAM disks without affecting performance. For example, a system with 512 Mbytes of RAM might be able to support a 256-Mbyte RAM disk without significantly affecting pagefile/swapfile activity. A system with 2 Gbytes of RAM might easily afford a 1 Gbyte or perhaps even a 1.5-Gbyte RAM disk without any pagefile/swapfile performance issue.
Unfortunately, there's no hard and fast rule for exactly how much system RAM you can assign to a RAM disk without affecting overall performance: It depends on the exact mix of software you'll be running. Fortunately, most RAM disk software makes it relatively easy to experiment with different-sized RAM disks, so you can find a size that works for your own unique situation. (We'll provide a list of RAM disk vendors later.)
Small RAM Disk Use: Data Sorts
If your system can only handle a smaller RAM disk, you still may find it quite useful: For example, if you need to perform an intense series of sorts or other file-intensive operations on, say, a 10-Mbyte spreadsheet or database, you'd probably see a significant speed increase by copying the spreadsheet or database into a modest 12- or 15-Mbyte RAM disk, and working on the files there. When you're done, copy the files back to the original location on the hard drive, and you're done.
Medium RAM Disk Use: Browser Temp Files
Things get even more interesting with larger RAM drives. For example, with a moderately sized RAM disk, you might be able to place your browser's history, cookies, or other temp files to a RAM disk (in Internet Explorer, you'd use the Tools/Internet Options/Settings/Move Folder tool). This not only speeds access to these files, but also can increase security: When you shut down the PC (and thus kill the RAM drive) everything stored in that drive goes away, leaving no trace. This approach could obviate the need for cookie-cleaners or other kinds of browser cleanup tools because all these files, if stored in a RAM drive, would be wiped out automatically at shutdown.
For a specfic example of how this can work, Winsoft's RAM disk (free limited-use version; $35 for full use) ships with two small batch files that you install via the Microsoft Management Console (MMC) included with Win2K and XP. The first batch file is meant to run automatically at startup. It enables the RAM disk, formats it, and copies whatever files you want seeded into the RAM disk from a folder on your hard drive. (e.g., something like "C:\Ramdisk_files") The second file runs at shutdown. It clones the RAM disk's contents to the permanent folder (e.g., "C:\Ramdisk_files"). In this way, the starting, stopping, and basic file management of the RAM disk can be quite automatic.
With a little judicious editing, you could adapt these files for browser-file management via a RAM disk. For example, start by cleaning out all unwanted cookies, temp files, etc., from your browser's normal temp file locations; but leave useful cookies such as those containing passwords, logins, etc. Copy this cleaned, known-good, known-safe Temp folder tree to a storage folder; continuing with the previous example, you might place the Temp files in a folder called C:\Ramdisk_files. The Winsoft startup batch file example would then start the RAM disk at boot-time, format the disk, and copy the cleaned, perfect browser Temp files from C:\Ramdisk_files to the RAM disk. You'd then surf normally.
At shutdown, instead of preserving the RAM disk contents via the second Winsoft batch file, you'd simply let the RAM disk files vanish at power down, wiping out all new cookies and other remnants from your online activities. At the next restart, the RAM disk would be recreated afresh, using only the pristine, known-good Temp files and folders. This way, your browser files would never accumulate all the garbage that normally accrues with surfing activity.
If that seems too convoluted, Cenatek's RAMDisk (free for 30 uses; $49 thereafter) is somewhat slicker, with much more configurable operation, a more-complete GUI, and even some semiautomatic customizations, such as helping you to capture your browser's Temp files. What's more, it uses a form of disk imaging to back up and restore the contents of the RAM disk automatically to prevent loss at shutdown; and can even automatically image the RAM disk as you work
Large RAM Disk Use: Speedy System Files
With a larger RAM disk on a system with lots of RAM to begin with, it's also theoretically possible to put some system files or even the pagefile/swapfile on a RAM disk, so that whatever Windows swaps out of system RAM will still remain in RAM (just in a different place) instead of being written to the actual hard drive. (Yes, it's a RAM-to-RAM swap, but it's still faster than RAM-to-physical disk.)
Win2K and XP allow you to split a pagefile across several drives or partitions. You'd set up your primary partition (usually C:) with a minimal pagefile--perhaps just a few megabytes. Next, assign all or most of your RAM drive to the pagefile. If the combined total of the pagefiles on C: and the RAM drive is less than the pagefile size recommended by Windows, create a third pagefile on another physical drive or partition until the three pagefile areas total the recommended amount. (For more information on how to do this, select Help And Support from the Start menu, and do a search for "virtual memory." Be sure to check out the "related topics" delivered by the search for additional good information.)
The idea here is that Windows will initially use the vestigial hard-drive-based pagefile on C:, but then switch to the RAM disk pagefile for the bulk of its operations; and then revert to additional space on the hard drive should it need to.
This may be harder to do in practice than in theory, however, because the operating system looks for its pagefile/swapfile early in the boot process, and if the RAM disk hasn't yet initialized, it won't be accessible for use. There can be other problems, too, depending on how the system identifies the RAM disk. This can vary from disk to disk, depending on what features the software vendor built into a particular RAM disk implementation. The only way to know if one will work on your system is to give it a try!
In any case, once you've seen several Ram Disk tools in operation, you'll come to know what they can do and how you might best be able to adapt them to your needs. Whether you have a honking big system with a ton of RAM, or a modest PC with not much RAM to spare, there may be a RAM disk solution for you among these pages:
RAM disks (meta list)
Sample RAM drive from Microsoft
RAMDisk For Windows
AR RAM Disk
WinSoft RamDisk (free trial, $35)
Many more
And when you're done, please tell us what worked and what didn't. Which RAM drives did you find best/easiest? What did you use them for? Did you notice an improvement in speed? Security? Join in the discussion!
To discuss this column with other readers, please visit Fred Langa's forum on the Listening Post.
To find out more about Fred Langa, please visit his page on the Listening Post