When it comes to improving the performance of your PC, purchasing additional RAM is despite the least expensive yet most effective route a person can take. While the solution appears simple, the dizzying array of memory available for purchase today can make the actual decision process problematic for all but the tech-savvy individuals. A very wide selection of differenting RAM types are available for purchase today, SDRAM, EDO, RDRAM, and DRAM to name a few. Knowing how to determine what RAM types are compatible with your current PC setup and what RAM choice will give you the greatest performance are key to making the correct decision.
The purpose of this guide is to give the reader a general understanding of what RAM is, what types of RAM exist, and how to decide what RAM would make the best purchase choice.
What is RAM?
The acronym RAM stands for Random Access Memory. RAM is where data is stored within your PC so that said data can be accessed by your PC's processor, or CPU. RAM should be considered as temporary memory within your PC, in order for RAM to maintain its data storage it must receive a continuous pulse of electricity. Any data that exists solely within a PC's RAM will be deleted when the PC is shut off or loses power.
PC's utilize several common technologies to store data internally on a more permanent level than RAM. These storage mediums include ROM – Read Only Memory, Hard Drives – which store data magnetically in a permanent – or depending on your usage – semi-permanent fashion, CDRWs, DVDRWs, Floppy Disks and Tapes. All of these data storage methods can be considered more reliable than RAM data storage, although none of them offer the speed of data access that RAM does.
RAM stores data that is essential for a PCs immediate operation and does so in an extremely fast and reliable way. RAM allows for a PC to operate at speeds that would be unachievable if it were replaced by more permanent data storage mediums. Think of RAM as a "fast lane" on an expressway. RAM allows for a function or application's most important data to have the fastest possible access to the processor. RAM exists as a "fast lane" for data that needs immediate attention by your PCs CPU. As such, the more RAM your PC has accesses to, the more "fast lanes" that are available for your PC's functions and applications to access your PC's CPU, the faster your PC will perform.
Types of RAM
SDRAM, DDR-SDRAM and RAMBUS are the three major types of RAM, or PC memory, in use today.
Before the introduction of SDRAM, PC memory is operated asynchronously from a PC's Clock Speed. This asynchronous operation would create data bottlenecks within a PC itself and slow overall performance. Clock speed is the speed at which a microprocessor executes instructions; Every computer contains an internal clock that regulates the rate at which data is processed and synchronizes a PC's individual components. As it stands to reason, the faster a PC's clock speed, the faster a PC's CPU can process data. Before RAM was synchronized to operate at the same speed as the rest of a PC's components, a PC's CPU would be would be forced into the occasional delay while waiting for the RAM to be available to accept data. In theory, as long as SDRAM operated at the same speed as the system clock, it would be available to the system on a regular and consistent basis – thus eliminating data bottlenecks. By regulating RAM and tying its performance to the system clock, memory manufacturers have been forced to increase memory performance to match PC clock speeds.
SDRAM – Synchronous Dynamic Random Access Memory – was the natural result of the PC industries search for better RAM and PC performance.
SDRAM is available 66, 100 and 133MHz speeds, known as PC66, PC100 and PC133 respectively. 66MHz RAM, in theory, would perform 66.6 million cycles per second and would be compatible with a 66MHz clock speed. Generally memory is considered to be backward compatible, so a pc with a clock speed of 100MHz could accept a memory module with a clock speed of 100MHz. The drawback being that the memory will only operate at the 100MHz speed.
SDRAM is no longer the memory of choice for modern PC's, however, due to the many PCs still on the market that utilize SDRAM, it is certain that memory manufacturers will continue to produce this memory for some time. SDRAM has been in the marketplace for some time and as such is widely available for purchase as a used yet guaranteed product. This used availability offers the buyer the opportunity to save a great deal of money on its purchase, yet sacrifice a bare minimum with regard to reliability as RAM has no moving parts and is generally very durable and long lasting.
DDR and DDR2 – Double Data Rate SDRAM – was again a natural result of the PC Industries search for better RAM and PC Performance. DDR memory has been available since the late 1990's and is a great leap forward in RAM performance. Essentially, DDR RAM achieves its improved performance by transferring data to the processor twice, instead of once in the case of SDRAM, per clock cycle. Theoretically, a RAM module that refreshes the processor twice per clock cycle should equate to twice the performance offered by SDRAM. In reality DDR does not really offer twice the performance of SDRAM, however it is a signaling improvement over the older standard.
Types of DDR and DDR2 memory that are available include PC1600 – 200MHz, PC2200 – 533MHz, PC4200 – 533MHz, PC4200 – 533MHz, PC3500 – 400MHz, PC3500 – The first number represents the maximum memory bandwidth, in megabytes, that a RAM module can provide per second. The second number, MHz, is the clock speed that the module is compatible with. As with SDRAM, the memory is backward compatible, a PC2100 chip with a 266MHz clock speed with work with a PC with a clock speed of both 266MHz and 200MHz.
DDR and DDR2 memory are the current standard in the PC industry and will continue to be manufactured for some time. As with SDRAM, DDR and DDR2 types have been in the market for some time and are available as used or refurbished. Both used and refurbished DDR memory can offer substantial savings when purchased while giving the user similar reliability to new product.
RAMBUS – RDRAM – was developed by the RAMBUS Corporation and can be considered to be a proprietary version of RAM as only the RAMBUS company manufacturers it. RAMBUS is a high-performance version of RAM generally found in high-end business class PCs. Today very few manufacturers use the RAMBUS standard as DDR and DDR2 memory offers similar, and in some cases better performance. RAMBUS memory can be found in speeds of PC800, PC1066 and PC1200. Usually you can purchase RAMBUS PC800- () the () will contain a number that references the chips speed in nano-seconds, ie PC800-45.
Memory and Performance:
While adding more memory does not ensure faster performance, not enough memory will guarantee slow downs. Having plenty of memory installed on your PC helps to ensure that your PC operates at its peak speeds and efficiency. Adding memory almost always results in a performance boost, especially if you run larger applications or multiple applications simultaniously. It is important to note that if you triple your current installed memory you will not see a three-fold boost in performance. You will almost always see some gain in performance, but you will go a long way in eliminating slow downs.
It will always be my contention and a good rule of thumb that you can never have too much memory. Maxing out you configuration with memory will help to guarantee the peak performance of your PC.
How to Choose Memory:
Choosing memory is dependent on several factors. First is the consideration of compatibility. Whether you are building a new PC or simply adding memory to an existing system, it is of key importance that the memory you purchase is compatible with your motherboard. Most motherboards accept a specific standard of memory, SDRAM, DDR, DDR2 or RAMBUS. To determine what type of memory that your PC will accept, you can either consult your motherboards owners' manual, or, if this is not available, inspecting the motherboard for brand and model number will allow you to go online and determine the compatible memory type .
Generally a motherboard that accepts SDRAM will accept memory modules that have a higher rated speed in MHz than what is specified by the board's manufacturer. For example, if your current motherboard has a clock speed of 66MHz and accepts PC66 SDRAM, you can install either PC100 or PC133 RAM chips. The board will only utilize the memory at its maximum speed however, so a PC133 SDRAM module will only operate at 66MHz speed. It is important to determine what RAM speeds – MHz – that your board is compatible with before making a purchase.
You should also consult either you owners manual or online documentation to determine the maximum memory that your board will support and physically inspect the board to determine how many available memory slots there are. Usually you will want to use the largest and fastest RAM chips that your board will support and fill all available slots with matching memory speeds. For example, your board has three available slots and currently one is in use by a DDR PC2100 266MHz RAM module. You discover that your board will accept DDR RAM up to PC2700 333MHz speeds. If you were to fill the remaining to slots with PC2700 memory, your memory would only function at the speed of the slowest RAM module, in this case 266 MHz.
New vs. Used:
Due to the sheer amount of memory manufactured within the last years, you will find an abundance of used memory for sale. When it comes to getting the most for your money, it should be noted that purchasing used memory is a great way to save money while getting similar reliability and performance as compared to new. RAM has no moving parts to speak of and as such is highly durable and reliable.
Spend some time researching prices between new and used memory modules. If you can purchase used or refurbished modules from sellers who will offer warranties, you may be making a major mistake spending that extra money on new RAM.
A little research on your part can help you to not only ensure that you see the maximum performance out of your PC set up, but also go a long way toward saving you money both in the short and long term.
Copyright 2006 www.hcditrading.com , Brad Calli