Pc Memory

PC’s have become increasingly memory-hungry in recent years, and the minimum desirable memory seems to go up year by year. Now, 8 MB of memory is no longer a large amount, it is the minimum required in most situations.

Types of Memory

ROM (read only memory)

Permanent memory that cannot be reprogrammed easily or cannot be reprogrammed at all and that retains it’s contents when the system is turned off. The basic input or output system software (BIOS) for a PC is installed in ROM.

DRAM (dynamic random-access memory)

Used for the main system memory in a PC RAM is memory that can be modified easily by the computer. Each memory location in DRAM functions like a little battery that is charged and discharged to store data. The charges in DRAM fade with time, and a memory-refresh operation is required to maintain data in memory. DRAM is not as fast as SRAM, but it is considerably less expensive and generally is used for system memory for that reason.

SRAM (static random-access memory)

A type of RAM that does not require a refresh operation. Memory locations in SRAM work like switches that retain their settings as long as power is applied. SRAM is faster than DRAM, but is used sparingly because SRAM costs considerably more. High-performance systems often use SRAM caches to buffer I/O to slower DRAM memory. Much of the performance of a high-speed system relates to the way in which the designers have used SRAM.

When you add memory, it’s important to obtain memory that matches the speed requirements of your system. All memory types have a speed rating that is specified in nanoseconds (ns). Speeds range from 40 ns (fastest and most expensive) to about 100 ns (much too slow for most new PCS). Most memory you encounter will have a speed rating in the range of 70 ns. Your system will not run faster if you buy memory that is faster than it requires. You might want to purchase memory, however, that is slightly faster than the minimum. Memory performance varies, and some manufacturers hold tighter tolerances than others. Buying faster memory ensures that the memory you buy will meet or exceed your system’s requirements.

Starting with the 80386, most CPU’s have the capability of out-running most DRAM, and system designers have used a number of techniques to slow down memory access. An early approach was to use wait states–“do nothing” operations that slowed down processing to a speed that the memory could cope with. Wait states are a serious drag on system performance, you should avoid systems that require them. The need for wait states was eliminated largely by the incorporation of cache memory into the system design.

Memory Expansion

The discussion about buses makes the point that most expansion buses operate at much slower speeds than faster CPU’s can support. A Pentium processor can perform burst-data transfers rates as high as 528 Mbps and is capable of outrunning even a PCI bus, which is limited to 60-66 MHz operation. For that reason, it is not practical to install memory expansion cards with most bus types. With the exception of some proprietary memory-expansion designs, it has become common to install all memory directly on the motherboard, where it can be more directly serviced by the microprocessor. A special memory bus on the motherboard operates at CPU speeds.

Most memory sold today is packaged in single in-line memory modules (SIMM’s), which consists of memory chips that are preinstalled on small circuit boards. When you obtain SIMM’s you need to be aware of several characteristics:

* SIMM modules have a width of either 1 or 4 bytes. One-byte wide SIMM’s use a 30-pin package and 4-byte wide SIMM’s use a72-pin package.

* SIMM memory capacities typically range from 256 KB bits to 8 MB bits.

* SIMM’s can be used individually. In many cases, however, SIMM’s are used in banks of two or four SIMM’s. You must review your system specifications to see what you need. On Pentium systems, SIMM’s must be installed in matched pairs.

All SIMM’S have a bit with. Traditionally, x86 PC’s have used parity memory requiring nine bits of memory for each byte of storage. IBM designed PC’s to use the ninth bit for parity checking of each byte of data. Parity checking is an elementary method for detecting memory errors. As a result, bit widths have typically been expressed in multiples of nine for Intel PC’s. Prior to the Pentium, many x86 systems used memory packaged on 9 bit SIMM modules. These modules incorporated memory that was one byte wide, usually with 9 bits per byte to implement memory parity. A SIMM with a 1 MB capacity would be configured as a 1X9 SIMM, meaning that its size is 1 MB bits by 9 bits.

Some 80486 and all Pentium systems use 32 or 36 bit SIMM’s in a 72 pin package. A 1X36 SIMM contains 4 MB of memory because it has a width of 4 bytes. Macintoshes have always used non-parity memory, a trick that has been adopted as a cost saving measure by many manufactures of x86 PC’s. By discarding the parity chip, manufactures can make use of less expensive 32 bit SIMM’s. A 1×32 SIMM carries 4 MB of non parity memory.

It is very important to match SIMM’s to your systems specifications. Also, if your system uses multiple SIMM’s in banks, try not to mix brands or even different production runs in a bank. SIMM’s can be arranged in banks so that a performance technique known as “paging” can be used. Paging distributes data for a byte across several chips, which might be in different SIMM’s in the bank. Unless the SIMM’s closely match each other’s characteristics, bit-read errors or parity errors might occur.


Parity is a primitive error checking technique that can determine when most errors occur but can’t correct errors. With the philosophy that no data is better than bad data, IBM designed the original PC to lock up when a parity error was detected. Parity errors are now relatively rare, and nearly all vendors have abandoned use of parity memory. Better than parity is error correcting (ECC) memory. ECC is a technique that not only detects errors but can correct errors that affect a single bit. ECC is a feature of a few elite super servers. The Pentium Pro has features that enable it to support ECC memory.

Memory and Windows NT Server

Windows NT Server, like most servers, is designed to take full advantage of any memory that is available. So that it’s not dependent on the performance limits of hard disks often the slowest things on a server-a network operating system makes heavy use of memory in order to cache data. This is one of the most important techniques for improving server OS performance.

Although Windows NT Server will run with 16 Mbps of RAM, you almost certainly want to add more. Windows NT attempts to keep the programs and data it is using in memory. When memory is exhausted, Windows NT uses disk-based virtual memory as adjunct storage. Although virtual memory enables Windows NT to keep more tasks in operation, the necessity of swapping code and data between memory and disk slows down processing considerably. Windows NT will perform much better if the programs and data it needs fit entirely into RAM.

Workstation Memory Requirements

The memory required for a workstation depends on the operating system. Software vendors will state minimum requirements for marketing purposes, but you usually will be rewarded by adding memory. As with servers, extra RAM enables workstations to reduce reliance on hard drives.

Here are some suggestions for memory with various operating systems:

*Microsoft Windows 3.1

Although it will run with 4 MB of RAM, Windows will spend an exorbitant amount of time swapping data to disk unless you have a minimum of 8 MB.

*Windows NT Workstation

The specifications say 12 MB, but more will improve performance. Besides, it’s easier to configure most systems with 16 MB of memory, so go for the extra 4 MB. Power users should have 24 MB or more for best performance.


Ignore the stated minimum of 4 MB and install at least 8 MB.


Install 16 MB or more.

DOS can’t directly access more than 1 MB of memory, but can use expanded memory to increase the memory available to applications. Expanded memory consists of extra memory, installed outside the DOS range, that is swapped into DOS memory in 4 KB to 16 KB chunks by a memory manager. An application can access one memory chunk and then request another. That method is not as good as directly accessing several megabytes of memory, but it’s better than being stuck with a 1 MB limit.

PC’s equipped with 80386 and later processors can simulate expanded memory without the need for special expanded memory hardware. This is accomplished by using an extended memory manager to make memory above 1 MB available to an expanded memory manager, which then performs the memory swaps.a

Memory Cards Complete Guide

Ever wondered what are these tiny chips? Confused by the names?
We are here to help you.

This article is about the various memory components available in the market for mobile phones.

Memory Stick

MS Memory Stick is a removable flash memory card format, launched by Sony in October 1998, and is also used in general to describe the whole family of Memory Sticks. This family includes the Memory Stick Pro, a revision that allows greater maximum storage capacity and faster file transfer speeds, and Memory Stick Duo, a small-form-factor version of the Memory Stick.

50.0 × 21.5 × 2.8 mm

Memory Stick Duo

MS Duo

31.0 × 20.0 × 1.6 mm

The Memory Stick Duo, which is slightly smaller than the competing Secure Digital format, was developed in response to Sony’s need for a smaller flash memory card for pocket-sized digital cameras and cell phones, as well as Sony’s PSP. Memory Stick Duos are available in all the same variants as their larger cousins (normal ones limited to 128 MB, larger Pro Sticks, with and without High Speed mode, with and without MagicGate support), and a simple adapter (often sold along with the Memory Stick Duo) allows a Duo to be used in any device that can accept their larger cousins.

Memory Stick Micro M2

15.0 × 12.5 × 1.2 mm

In a joint venture with SanDisk, Sony announced a new Memory Stick format on 30 September 2005. The new Memory Stick M2 (“micro”) measures 15 × 12.5 × 1.2 mm and could theoretically have 32GB in the future. Maximum transfer speed is 160MB/s. It will come with an adaptor, much like the Duo Sticks, to ensure compatibility with current Pro devices.

Multi Media Card


32 × 24 × 1.5 mm

The MMC card or MultiMediaCard was introduced in 1997 by SanDisk Corporation and Siemens AG. At that point the MMC card was the smallest memory card, about the size of a postage stamp, in the market based on flash memory technology. The MMC card is very similar to the Secure Digital Memory Card, actually the SD Memory Card is based on the MMC card. They have almost the same form factor the only differences are that the SD Memory Cards are slightly thicker and they have a write protection switch.

Since the MMC card had slow transfer speed, 2.5 MB/sec, in comparison to other memory cards, mostly compared to SD Memory Card, a new high performance version of the MMC card was introduced in 2005 by the name MMCplus. The MMCplus has today the highest, up to 52 MB/sec, theoretical data transfer speed in the whole memory card industry.

The MultiMediaCard Association announced that by the end of 2005 the secureMMC application will be available only for the MMCplus and MMCmobile memory cards. The secureMMC is a copyright protection application that features DRM, Digital Rights Management, and VPN, Virtual Private Network, capabilities.

Reduced Size Multi Media Card


16 × 24 × 1.5 mm

MMCmobile (RS-MMC)

RS-MMC, Reduced Size MultiMediaCard, was introduced in 2003 by the MultiMediaCard Association (MMCA) as the second form factor memory card in the MultiMediaCard family. The RS-MMC is a smaller version of the standard MMC card, approximately half in size, and was specifically designed to be used by mobile phones and other small portable devices.

Dual Voltage Reduced Size Multi Media Card


16 × 24 × 1.5 mm

In 2005 the Dual Voltage (DV) RS-MMC was introduced. It is basically the same card like the standard RS-MMC but operates with dual voltage, 1.8V and 3.3V, leading to lower power consumption which contributes to longer lasting battery life for the host devices. The DV RS-MMC and the RS-MMC are completely compatible with each other but since some mobile phones, mostly from Nokia, only operate with 1.8V cards the regular RS-MMC will not work. We recommend to always buy the Dual Voltage RS-MMC for being sure your memory card will function with the electronic device.

MMCmicro Card


12 × 14 × 1.1 mm

The MMCmicro, formerly known as S-CARD introduced by Samsung, was adopted and introduced in 2005 by the MultiMediaCard Association (MMCA) as the third form factor memory card in the MultiMediaCard family. MMCmicro is the smallest, about the size of a fingernail, memory card in the MultiMediaCard family and among the smallest in the world. It was specifically designed for being used in mobile phones and other small portable devices.

The MMCmicro memory card is available with an adaptor, MMCplus. This makes it not only compatible to all MMC and MMCplus slots but also to all SD Memory Card slots. It is important to keep in mind that music stored on MultiMediaCards my not be able to play back when inserted into a SD Memory Card slot due to the copyright protection features supported by the SD slots.

Since the MMCmicro is the latest memory card to be developed and introduced to the market it is not that compatible to many mobile phones and electronic devices yet. Still it is expected to be one of the memory card formats that will dominate in the mobile phone industry among the frontrunner microSD and the under development Memory Stick Micro.

Secure Digital Card


32 × 24 × 2.1 mm

The SD Memory Card or Secure Digital was introduced in 2001 by SanDisk Corporation, Matsushita (Panasonic) and Toshiba. The SD Memory Card was based on the MultiMediaCard, MMC, memory card standard and has almost the same form factor, the size of a postage stamp, the only differences are that the SD memory card is slightly thicker and has a write protection switch. Since MMC cards are thinner than SD Memory Cards they can be used in all SD Memory Card slots but not vice versa.

The SD Memory Card is today the most common used memory card. It can be found in most digital cameras, PDAs and in many other electronic devices. The SD Memory Card slots can be used for more than flash memory cards. The SDIO, Secure Digital In & Out, is the general name for the many expansion modules that can be found in the SD Memory Card’s form factor. SDIO modules can be inserted in the slot and be used for other functions like Bluetooth adapters, GPS receivers, digital cameras, TV tuners, etc

miniSD Card


21.5 × 20 × 1.4 mm

The miniSD was introduced in 2003 by SanDisk Corporation in cooperation with Matsushita (Panasonic) and Toshiba. Later in that year the miniSD format was adapted by the SD Card Association as the second form factor memory card in the Secure Digital family. MiniSD is a smaller version of the SD memory Card format, about 60% smaller in volume, and offers the same benefits as the SD Memory Card expect of the writing protection switch.

MiniSD was designed specifically to be used in small portable electronic devices like digital cameras and mobile phones. But since all miniSD memory cards always come with a SD Memory Card adaptor, they are compatible to all SD Memory Card slots and thereby provide compatibility with the rapidly growing number of SD Memory Card compatible devices in the market.

MiniSD was the second, after SD Memory Card, memory card to be adapted by the SD Card Association, which today consists of three members. In 2005 the microSD was introduced as the third, and smallest, member of the Secure Digital family.

microSD Card also known as Transflash


11 × 15 × 1 mm

rashFlash, formerly known as T-Flash, was introduced by SanDisk Corporation in 2004 as the world’s smallest memory card, approximately the size of a fingernail. TransFlash was specifically designed for being used in mobile phones. Motorola was the first mobile phone manufacturer to adapt the TransFlash memory card standard.

In the 3rd quarter of 2005 TransFlash was adapted by the SD Card Association as the third form factor memory card in the Secure Digital family, after SD Memory Card and miniSD. After the adoption, TransFlash changed name to microSD. The microSD has exactly the same dimensions and specifications as the TransFlash and therefore both memory cards are completely compatible to each other.

Today the microSD is the most common used memory card in mobile phones and the SD Card Association’s objective is to make microSD a de facto memory card standard for all mobile phones. All TransFlash and microSD cards always come with a SD Memory Card adaptor, which makes them compatible to all SD Memory Card slots. The microSD is about 10% in size compared to SD Memory Card and about 30% compared to miniSD.

xD-Picture Card


20 × 25 × 1.7 mm

The xD-Picture Card was introduced in 2002 by Fuji Film and Olympus as a replacement to the older SmartMedia Card. It is produced exclusively by Toshiba and can be found branded only under the name of Fuji Film and Olympus.

The xD-Picture Card format was developed to be used in digital cameras and is more or less only used in Fuji Film and Olympus digital cameras. Like SmartMedia Card, the xD-Picture Card does not incorporate a controller chip which allows it to have a small form factor but at the same time making it dependable to the host device’s controller chip.

Grab The Best HP Memory

HP Memory and Compaq memory are compatible and flexible digital storage devices exclusively designed for the HP and Compaq computers. The storage devices show best performance and above all it is a complete value for your money. If you want to go for HP memory upgrades, you have plenty of options to secure, and moreover you can also avail quick and real discounts without the hassles of spending too much of your precious time out there on internet. HP and memory cards are not only a good match for only HP and Compaq computers, but the memory also gives value added performance for printers, laptops, palmtops, scanners etc manufactured by many other reputed digital services brands. When you buy HP Memory or Compaq Memory for that matter, you get peace of mind as you are paying for the internationally renowned memory cards and storage devices that are known for their quality and high performance.

As against the other memory and storage devices manufacturers competing out there in the digital storage market, HP and Compaq are known for their very own niche and quality computer memory and digital storage devices. You just don’t have to worry about the performance and quality when you go for storage devices from HP and Compaq. The best thing when you buy HP memory and Compaq memory is that you can avail easy discounts, and not to speak of the quality, integration, reliability and confidence that will make you go for the smart storage devices.

The Compaq memory and HP Memory cards or rather flash memory cards are utility purpose digital storage devices that allow the users to write and re-write the data that can be used over and over again for the various official and generic use. Further, HP and Compaq memory comes in variable sizes. With the innovative and next generation nano technology you can buy the micro size flash memory cards and memory cards from HP and Compaq. It is the use of nano technology that HP and Compaq memory devices are the best fit for the portable consumer electronic devices that will give the electronic equipment the advantage of high efficiency and perfect output.

HP and Compaq are manufacturing advanced memory and flash memory cards that can be easily integrated with any digital device which demands use of high performance memory. The new PCs from HP and Compaq make use of Compaq memory that did fast processing speed, besides efficiency in offering seamless output. HP and Compaq memory have become popular digital devices that will turn your computing into a high speed activity and you will enjoy the performance as the digital processing reach the highest echelons.

The best part is that HP memory as well as Compaq memory storage devices is also a perfect match for Handycams and digital cameras. The storage devices from HP and Compaq are checked on various parameters, and it is the application of stringent quality procedures that ultimately give your digital devices the lead from the range of sub standard digital devices.

If you are serious about installing HP memory or Compaq memory in your computer or any other digital device, just don’t think for a second, as the memory storage devices are just fabulous and efficient to give computing the best and smart performance.

Computer Memory – Upgrade for High Speed

Computer memory is the soul of your computer. Basically, it is of three types -RAM or the random access memory, ROM or the read only memory, and the hard drive memory. RAM computer memory is used by the computer processor for processing the information. It is a temporary memory, and the moment computer is shut down, every piece of data in the RAM is lost. It is at this point of time that computer flash memory comes into the picture. RAM is further classified into different types such as extended data out (EDO); fast page mode (FPM); single data rate (SDR); Synchronous Dynamic RAM (SDRAM); double data rate -first generation (DDR1); and the double data rate -second generation (DDR2) respectively.

ROM is the memory that is stored on the computer’s motherboard. The memory has all the data which is required by the computer for starting it smoothly. Since it is a read only memory, ROM can only be used for reading purposes and not for writing. Hard drive memory on the computer is the memory located on the physical drive and which can be used for storing huge amounts of data at any given point of time. The data can be easily recovered from this computer memory after the computer is switched on. Hard drive memory is a computer memory that can be used for longer duration of time.

Whether it is Dell or Apple memory or for that matter memory of any other assembled computer system, the central role of the memory remains the same, which is to store high quantity of data and make it available for use for information purposes. With increase in the resources, the requirement for computer memory upgrade becomes a necessary aspect. Upgrading the memory of computer system is very easy and not a cumbersome task and it takes only few minutes of your time. When you go for upgrade of computer memory, there’s substantial increase in the performance of your computer system as it now takes much less processing time.

Computer memory upgrade for Apple requires different procedures altogether than the procedures that are other wise required by the PC. There can be many reasons for the shift in procedures when considering memory upgrade and apple memory. The primary reasons that are otherwise responsible are differences in the configuration of RAM, Motherboards, and Graphics Cards etc. Therefore, the computer memory specifications, in case you are thinking of memory upgrade, are directly related to the hardware compatibility of the resources.

If you are not aware about the configuration of your PC, then it might not be possible for you to easily do the task of upgrade. In such a situation it’d be a good idea that you go for hardware professional that will give you the service and change the computer memory of your system for good performance and fast response time. It is important to note here that computer memory, irrespective of the fact, whether it is RAM, ROM or Hard disk, is meant to give efficiency, only if it is compatible with other hardware resources.

If memory is not compatible then there are possibilities of hardware and software conflicts occurring; and this will completely deteriorate the performance of the computer system sooner or later. Make sure that you keep the point in your mind.

Apple Mac Memory – Powering Your Mac Machine

Memory is one of the most important equipments of a computer machine. It actually powers the computer and allows it to process and perform its functions further. However, just like other machines and spares have a specific life time so the computer memory has. Every computer machine, be it a desktop, server, laptop, notebook or a net-book, needs a memory upgrade. You will need to upgrade your computer memory to ensure its optimum performance and your experience of happy and uninterrupted computing. Computers of all makes need updating memory and Apple memory upgrade is not an exception.

Enhancing memory of your computer becomes essential when your computing needs increases. That means, when you start using your machine for running heavy software programs, playing the latest and hottest games or due to any other reason. If your Apple Mac PC has become slow then you need not dump it or buy a new one. Simply consider Apple memory upgrade will do and give you the performance that you deserve. Having optimum memory is crucial for all computer machines and when you provide them with that, you can be assured that you will get your hands on the performance of your computer that it use to give you when it was brand new.

What you need to do –

You need not worry a lot for the slow speed of your computer. Upgrading your computer memory with the right memory make will simplify your problems and optimize the processing of your system. What you need to do is identify or estimate your computing needs. This may include analyzing the consumption of computer memory that your software programs of video games do. Now check for the memory available and how much memory you will need to run your heavy programs on your existing computer architecture. Once analyzed, you may go for a completely new memory for your machine or upgrade it with an add-on memory to optimize its performance.

You may do the analysis easily by yourself or may contact your vendor. If you have Apple Mac computer with you then upgrading it with Apple memory becomes easier. This is because of the fact that Mac computers are different from computers of other brands like IBM, Dell, HP, etc, and so are the memory modules. However, having proper knowledge of your Mac machine and the memory it uses is very important. If you know which memory module does your Apple computer uses then you can easily get memory upgrade of your computer. You can simply visit market and get a relevant memory for your Mac or research online for web stores that are selling memory online.

You need not worry if you do not know much about your Mac PC. Just click on the web to get full information about your system and memory that it uses. You may also get the same information from the online retail stores. In fact these retail stores will also give you information about the compatible memory for your machine. Once you find the right memory for your system, place your order and your shipment will be delivered right at your doorstep within specified business days.

Time to enjoy optimum performance of your computer –

Once you get your computer memory for upgrade, you may install it into your computer by yourself. However, you must do this if you are friendly with the hardware architecture of your system. If you are not savvy with the hardware then calling your vendor is a better option. And if it is Apple memory then it is important that you get it installed by a professional if you yourself do not know much about your Mac PC. As mentioned above, Apple computers are different and so is the memory. Finding memory is easy but installing may not be, if you are not friendly with Apple technology.

Leave a Reply

Your email address will not be published. Required fields are marked *