I spend a lot of hours each day on the computer. If you’re like me, you don’t just want your computer to run its best, you need it to. If you’re getting a slow response from your computer, then getting it back up to speed is top priority.

Your computer could be running slow for several reasons, and there are some quick fixes for most. But this article focuses on the one that isn’t so easy to fix, and what you can do to help. I’m talking about the registry.

First let’s list the easy ones:

1. Full Hard Drive
- Use Windows CLEANMGR to free up some space

2. Adware/Spyware/Virus
- Get some sort of virus protection – it’s cheap insurance

3. Fragmented files
- The Windows Disk Defragmenter can have your files ship shape in no time

4. Opening lots of programs at once
- You can install more memory for a few bucks
- Or, for a few bucks less you can use ReadyBoost
- Or, for free, you can just open fewer files =)

5. Your Registry could be corrupt or bloated
- Learn to use REGEDIT,
- Or get a Registry Cleaner

Let’s focus on the fifth possibility, your registry…

For those that don’t know, your registry is your computer’s frontal lobe. Everything it knows about itself is stored here. I mean everything.

If your computer has a question about how, why, when or where it should do something, it will either ask you, or ask the registry. If it asks you and you give it an answer, guess where your answer gets written down? Yup, in the registry. So basically, your computer won’t cross the street unless it gets permission from the registry.

When new programs get loaded on your computer, they write loads of information into the registry. They put things in here that your computer needs to know in order to run them. Sounds good right? But, what if they make a mistake and write something that confuses your computer? Or Worse; what if you delete the program and it leaves information in the registry instead of removing it like a good program should?

The short answer is that, over time your registry gets errors and it slowly (sometimes not so slowly) gets bigger too. When this happens everything takes longer and your computer’s response slows down.

You’ve got 2 options here; learn to use REGEDIT, or get a registry cleaner.

REGEDIT is not a very user friendly program to say the least. Many books and websites have been dedicated to how to use it to modify your registry. If you go this route, be sure to make backups of critical data and restore points before you even open it. Mistakes here can be costly.

Registry cleaners are easy to use, and they are easy to find; just search for registry cleaner and you’ll get loads of hits. The majority offer a free scan, so definitely look for one that does.

Once you settle on one you like, use it once every week to keep your computer in perfect health and make slow response a thing of the past.

source: http://ezinearticles.com/?Computer-Slow-Response—Could-the-Registry-Be-to-Blame?&id=5910167

Anybody with a computer knows that computers are unpredictable. Before we are forced to call in an expert, there are a few things we can try on our own to get that computer to behave. Assuming you are a home user, here are some Basic Computer Troubleshooting Tips To Try On Your Own. This article may not help you to solve today’s problem, but it should help you with the overall troubleshooting process.

Keep in mind that there are many types of problems. They can be hardware related, software related or even network related. The first step to solving a computer problem is to pay close attention to any messages that are displayed. It is surprising how many people close the message boxes without really reading them. This is an important key. Often, the message will indicate the source of the problem. Many times, software is the culprit to a problem. Knowing what program is producing the message can be a big help.

If you still do not understand the message, go to the internet and type the message into your search box. Even experts use this tactic. You will be surprised by the amount of results. Chances are, there are dozens of other people experiencing the exact same problem.

Solving a computer issue can be similar to the work of a detective. Sometimes there is no message. In this case, ask yourself when the problem started and what were you doing. If your screen suddenly goes black and you just moved your computer, this can be a good indication that the plug or even the video card itself came loose.

If you were busy using your photoshop and dreamweaver applications, a black screen could also mean that you had too many programs open and the memory conked out. Restarting can be a miraculous cure to many a problem. Restarting can solve a printing problem, an internet problem, a freezing problem and more. Basically, a restart stops any processes that are running, including the unwanted ones.

There are occasions when restarting the computer will not keep a computer from freezing. One of the most common reasons for an extremely slow or freezing computer is having more than one anti-virus program running. If you do not know what a particular problem is, system restore is also a good thing to try.

Sometimes a problem can be of a completely different nature. Perhaps the current issue is an annoying toolbar or trying to find a lost document. Again, use the internet for answers. Type in your question and keep it simple and specific. You might type something like: How to remove zango toolbar. Or you might try something like: Locate lost word document.

Because of the myriad amount of possible problems, it would be quite an impossible feat to cover even a vague amount of remedies here in one short article. Knowing how to read and understand messages is the first step. Knowing when to reboot is another. When all else fails, there will always be someone to call. Do not ever allow yourself to become too frustrated.

source: http://ezinearticles.com/?Basic-Computer-Troubleshooting-Tips-to-Try-on-Your-Own&id=4550412

The term overclocking is thrown around a lot, for better or worse. If you’re one of the many who has never overclocked, this guide will explain what it is and how to do it to the computers’ processor, motherboard and memory.

The prospect of overclocking a computer system can be intimidating for a computer newcomer, to say the least. The idea is simple enough; make the computer’s processor run faster than its stock speed to gain more performance without paying for it. The execution of this idea though, can be anything but simple.

Successful overclocking is as often a matter of ‘what you know’ as ‘what you have’. Understanding the maze of hardware dependencies and tweaks that can make the difference between a successful overclock and total failure is a demanding practice.

In this Beginners Guide, we will explore the process of overclocking processors, motherboards and memory to achieve a faster yet still stable computer. The article will guide readers step-by-step through understanding overclocking concepts, how to discover their hardware’s overclocking options and the actual process of overclocking. If you consider yourself an expert already, read on – there are a few tips and tricks packed into this guide that you may not know… or have a look at our recent experiment with underclocking. For insight into videocard overclocking, please see our companion guide on that subject right here.

What Does Overclocking Do?

Overclocking a computer’s processor or memory causes it to go faster than its factory rated speed. A processor rated at 2.4GHz might be overclocked to 2.5GHz or 2.6GHz, while memory rated at 200MHz might be pushed to 220MHz or higher. The extra speed results in more work being done by the processor and/or memory in a given time period, increasing the overall computing performance of the PC.

Can Overclocking Damage Computer Hardware?

Yes, but it’s typically unlikely. Generally speaking, when computer hardware is pushed beyond its limits, it will lock up, crash or show other obvious errors long before it gets to the point where the processor or memory might be permanently damaged. The exception to this is if extreme voltages are used when attempting to overclock, but since most motherboards do not support extremely high voltages, and neither does this guide, it’s not likely to be an issue.

For older processors, heat is also a factor worth keeping a close eye on. Modern processors have thermal sensors which will slow down or shut off the PC, but older CPUs do not necessarily feature these safety devices. The best know example of this is the AMD AthlonXP (socket A/462), which was famous for burning itself up in less than 5 seconds if the heatsink was not installed properly (or at all).

The Purpose of Overclocking

The most obvious reason to overclock a computer system is to squeeze some additional performance out of it at little or no cost. Overclocking the processor and system memory can significantly boost game performance, benchmark scores and even simple desktop tasks. Since almost every modern processor and memory module is overclockable to at least a slight degree, there are few reasons not to attempt it.

Important Overclocking Concepts

The following terms will be used throughout this guide, so it’s important to get a good grasp on them now.

FSB (FrontSide Bus): The data bus that carries information from the processor to the main memory and the rest of the system. A processor’s internal multiplier multiplied the FSB speed of the system = that processor’s speed in MHz or GHz.

Increasing the clock speed of the FSB (and thus the speed of the memory and the processor as well) is the most common and effective way of overclocking a modern computer.

AMD Athlon 64-based systems do not use a conventional FSB since the memory controller is built right onto the processor’s core instead of being located in the motherboard’s core logic chipset. Instead, a value called motherboard clock speed is used to determine the speed of data transfer between the processor and the memory. For the purposes of this article, FSB and motherboard clock speed are interchangeable terms.

Internal Multiplier: The ratio of a given processor’s speed (in MHz or GHz) as compared to the FSB (Frontside Bus) speed of the computer system it is installed in. A processor with an internal multiplier of 16x installed in a system with a FSB of 200MHz would run at 3.2GHz internally, since 16 x 200MHz = 3.2GHz. Most modern processors are ‘multiplier locked’ to some degree, meaning that their internal multiplier cannot be changed (or at least increased). This in turn means that increasing the FSB speed of a system is the only way to overclock the processor.

Memory Divider: Most modern Intel Pentium 4 and AMD Athlon motherboards allow a memory divider to be set. This divider allows the system memory to run slower than the actual FSB speed. By default, FSB speed and memory are usually set to a 1:1 ratio, meaning that increasing FSB speed (by overclocking) increases memory speed by the same amount. Most ‘generic’ system memory is not built for overclocking and thus may not be able to take the level of overclocking that the processor or motherboard can achieve.

The memory divider allows users to mitigate this problem by reducing the speed increase of the memory relative to that of the FSB and the processor. Setting a 5:4 memory divider would mean that memory speed increases at 4/5th the rate of the FSB, for example.

Reducing the relative speed of the memory does result in a slight decrease in performance as compared to the default 1:1 ratio between FSB and memory speed, but it may help users with generic memory achieve a higher overclock.

Stock Speed: The default or factory speed settings of computer hardware like the processor, memory and motherboard. With the processor, stock speed refers to the clock speed in MHz or GHz of the processor. With the memory, stock speed refers to the highest standard memory speed that the memory module is rated for (PC3200 DDR memory has a stock speed of 200MHz, for example). In the case of the motherboard, stock speed refers to the default speed at which the processor and memory work together, the FSB speed.

To tie this all together, say a motherboard has an Athlon XP 3000+ processor installed (stock speed 2.1GHz) which uses a FSB speed of 166MHz. A PC3200 DDR memory module (stock speed 200MHz) is installed. Since the processor requires a 166MHz FSB, the motherboard will set the memory speed to 166MHz which becomes its stock speed with the current configuration.

Core/Memory/Chipset Voltage: These three voltage values represent the amount of electrical power being fed to the respective components. When a processor, memory or motherboard is made to run faster due to overclocking, more voltage may be required in order for that component to run stably. With this in mind, voltage adjustment is one of the most important principles of overclocking.

If an overclocked computer becomes unstable, increasing one or more of these voltage settings by a very small amount (0.05V to 0.1V) can often mean the difference between an unbootable system and a stable overclocked one. That being said, it is important to make some distinctions with respect to voltage adjustments; more voltage does not necessarily mean faster speeds, rather minor increases can help improve stability. Computer circuits are designed to operate within very specific electrical ranges, and drastically increasing the electricity being supplied to a chipset will raise temperatures, and potentially damage it.

The role of the CPU, motherboard and memory in overclocking

When overclocking a computer, the processor, system memory and motherboard all have a different and important part to play in the process. The abilities and overclockability of each component has a significant effect on how successful the whole experiment will be. Let’s take a closer look at each component:

The Processor (CPU): As readers might know, two important variables govern how fast a modern processor goes. Its internal multiplier and the FSB (Front Side Bus) setting of the motherboard and memory. The FSB is the effective speed of data transfer between the processor and the main memory (it’s also the base speed that the system’s memory runs at), while the multiplier is an internal indicator of the speed of the processor.

A processor’s speed equals its multiplier (x) the FSB in MHz. Therefore, an Intel processor with a multiplier of 16 working with a FSB speed of 200MHz would run at 3.2GHz. There are two ways a processor can be made to run faster; increasing the multiplier, or increasing FSB speed.

Many modern processors have ‘multiplier locks’ which prevent users from changing the internal multiplier settings partially or completely, so increasing FSB speed tends to be the most common and effective method of overclocking.

The Memory: A system’s main memory speed determines the speed of data transfer between the processor, memory and the rest of the system. As you can imagine, this is the most important variable for computing performance in some systems. In all modern Intel and AMD systems, the FSB speed is directly linked to the speed of the memory by default, so the faster the memory is clocked, the faster the processor goes, since processor speed = (internal multiplier (x) FSB speed). This can be changed, but the 1:1 ratio between FSB and memory speed is the most desirable for overclocking.

AMD Athlon 64 systems do things a bit differently, since the memory controller is part of the CPU itself, so there is no conventional FSB carrying data from the processor to the rest of the system. Overclocking the memory still works essentially the same way, though the technology/terminology has changed. More on this in our AMD overclocking section below.

The Motherboard: Just as the motherboard is the heart of every computer system, it is also central to your overclocking efforts. The motherboard’s circuitry connects the processor and memory together and its BIOS options determine in what ways and by how much they can be overclocked. Even the highest quality memory and most overclockable processor can accomplish nothing if placed in a motherboard with no or limited overclocking options in its BIOS, or a board equipped with a new, poorly implemented or unstable core logic chipset.

Again, each component above depends on the other two when it comes to overclocking.

Hardware considerations for overclocking: Heat and cooling

The faster a computer goes, the more heat it produces. This is especially true when the voltage being fed to certain components is increased, a standard overclocking method. Excess heat in the processor, motherboard chipset or memory can cause crashes and system instability, and may be one of the limiting factors in determining the maximum overclock for a system.

The stock heatsinks included with most processors are perfectly adequate for cooling them at their stock speeds, but may not handle the additional heat generated by overclocking very well, especially if the computer chassis is not suitably ventilated. Readers may be better off investing in one of the many custom cooling solutions on the market, or at least buying some case fans to ensure an adequate flow of fresh air through their case. Take a look here for some cooling ideas. The same goes for the chipset and to a limited degree, the memory.

Hardware Considerations for Overclocking

It’s also important to keep an eye on the amount of heat the processor is putting out because of the ‘thermal throttling’ safety systems built into both AMD Athlon 64 and Intel Pentium 4 processors. If either of these CPUs gets too hot, they will slow themselves down drastically in order to keep from burning out. Users will notice this in terms of massively reduced system and benchmark speed, which should clue them into the fact that additional cooling is needed if they wish to continue overclocking. Thermal throttling should never occur in the regular use of a processor, but overclocking is NOT regular use.

To monitor the processor’s temperature, look for the ‘system health settings’ or similar entry in the BIOS screen.

Though some CPUs run hotter than others (Pentium processors tend to displace slightly more heat than their AMD siblings), all modern processors are happiest in the area between 35°C -65°C. If the processor is showing temperatures over 70°C in the BIOS, chances are that heat is going to be a limiting factor in the computer’s stability and overclocking potential. Time to consider a new heatsink and/or better case ventilation.

Power Supply Requirements

Overclocking a computer system also increases the amount of power it draws, and this may lead to system instability if its old 300Watt power supply is not up to the task. If overclocking a modern Pentium 4 or Athlon 64 system, plan on upgrading the power supply to at least 400Watts.

Spontaneous reboots while under load are usually a sign of insufficient power. When that happens, it’s definitely time to pick up a new power supply. On that note, while flashy powersupplies full of lights may be good to look at, they do not always indicate the best power quality, or power efficiency. In our experience, powersupplies which support PFC or Active PFC are the best choices.

Principals of Overclocking

Before we (finally) get to the practical part of the guide, here’s a brief word to prepare readers for the almost inevitable periods of frustration to follow. Overclocking is a very imprecise science; the processor depends on the stability of the motherboard and memory in order to achieve overclocking, and vice versa. If one of these components cannot stand the stress of overclocking, it will limit the other two also.

Heat, voltage and power supply stability are also relevant to overclocking success. Excess heat, not enough or too much voltage and unstable power can all cause the premature failure of an overclocking adventure, and it’s next to impossible to pinpoint what is causing the problem.

To avoid frustration as much as possible, be patient. Follow the directions below and take overclocking one small step at a time, so that when trouble occurs you will have a smaller set of potential issues to troubleshoot.

Preparing for Overclocking

In order to get the best out of current hardware, the most recent drivers and BIOS version for the motherboard need to be acquired. System benchmarks should be run pre-overclocking to establish a performance ‘baseline’.

Readers should visit their motherboard manufacturer’s website to obtain the most recent set of drivers for their motherboard, as well as the most recent BIOS version. For instructions on finding the current BIOS version and overwriting it with a newer edition. Newer BIOS versions may add overclocking options and stability, so this is always a good first step.

Establish a Performance Baseline

In order to get a good idea of how overclocking increases the performance of a computer, it’s important to take benchmarks and establish a performance baseline for the system.

Download, install and run the following benchmarks:

* 3Dmark2001SE
* X2: The Threat (download the demo and use the ‘run as a benchmark’ checkbox when loading it.)
* PCMark04
* Sandra 2005 (CPU, multimedia and memory benchmarks)

Record the results of each test. This will be the performance baseline, a level to measure the soon-to-be overclocked computer system against.

Readers should also consider downloading the Prime95 burn-in program, since it is extremely useful for stress testing an overclocked PC to ensure stability.

Examining BIOS Options

Since the motherboard controls what options you have for overclocking, it’s essential to take a look at the BIOS (Basic I/O System) pages of the board to examine the options available.

Reboot the computer and go to the BIOS screen by pressing the DEL key repeatedly during startup.

Note that some motherboards respond to different key commands to bring up the BIOS. Dell computers for example often rely on F2 or F8, while other manufacturers may opt for F10 to bring up the BIOS.

When the BIOS comes up on the screen you will be greeted with a blue menu with about a dozen headings. Navigate through the list by using the arrow keys, and press ‘enter’ to select a menu. When you’re done press the ESC key to exit, and either save or discard any changes you’ve made to the BIOS settings.

The first features to look for are CPU and FSB speed adjustment controls. Generally, these will be in a section of the BIOS called ‘frequency/voltage control’.

As seen in the screenshots below, this page will contain the FSB adjustment controls and voltage adjustment controls.

Increasing the FSB or ‘CPU host frequency’ or (Motherboard Clock or FSB or a host of other terms for the same thing) will increase the FSB speed of the motherboard, overclocking the processor and memory at the same time.

Increasing the voltage to the CPU core, memory or chipset will feed more power to those components to aid in stability while increasing heat.

This page may also contain memory divider options depending on the motherboard.

Everything needed to overclock the system should be on this one BIOS page.

Different motherboard’s BIOS screens will look different and use different names for the various menus and options, but the options themselves should be grouped together in one menu as seen above. If the memory timings options are not visible, try hitting CTRL+ALT+F1 when entering the BIOS.

The second BIOS page that should be identified now is the ‘PC health status’ page, or similar.

This page contains the readouts from the motherboard’s temperature monitors, allowing users to check how hot the processor is running.

In Case of Disaster

Though it’s less common with modern hardware, it’s quite possible that during this overclocking adventure the computer system may be (over)driven to a point where it simply refuses to even POST, never mind boot into Windows. If this happens, don’t panic.

To restore a system in this condition, power down the computer, unplug it and restore the BIOS to its default settings. This can be accomplished in one of two ways:

Set the BIOS (CMOS) reset jumper on the motherboard into the reset configuration and leave for 20 seconds (consult your manual for its location), then reset the jumper to the default position and power the system on again. The BIOS should now be reset to its default settings.

Or – Remove the CMOS battery (the flat silver disk) from the motherboard using a pencil or similar implement. Leave it out for a minute or two, then replace it and power on the system. The BIOS settings should have been reset, allowing the computer to boot.

Or – While turning on the PC, hold down the Insert key until the POST screen is displayed, enter into the BIOS and select default settings, save and reboot.

Memory Performance (latency vs. speed)

Memory latency is another important consideration when overclocking a computer system. The latency settings of the memory determine how long it waits for certain states to clear before performing new read or write actions. The lower the latency, the faster the memory will perform. Lower latency settings put more stress on the memory and increase the chance of error though, so many lower-end memory modules cannot handle fast latency settings, especially when overclocked. Raising the memory’s latency settings may enable a higher overclock to be achieved at the cost of some performance.

Memory latency settings can generally be found in the ‘advanced chipset features’ section of the BIOS.

source: http://www.pcstats.com/articleview.cfm?articleid=1804&page=1

Other than the CPU and motherboard, the RAM (Random Access Memory is the next most important hardware in your system.

When a computer first boots up, the system loads data from the hard drive into the RAM. At any point of time when the CPU needs any information, it will access the RAM to retrieve the data it needs. Since the RAM transfer data at a speed faster than any other storage media (such as the hard drive, CD-ROM and floppy disk), the retrieval process is shorter, work gets done faster and hence the computer performs better.

How does the RAM affects the performance of your gaming computer?

The amount of RAM you have in your gaming computer affects the speed at which the game reacts. To process the huge amount of computation involve in a 3D game, there must be enough RAM to store all the information. For systems with a small amount of RAM, the memory space will be filled up easily and all overflow data is then written or page to the hard drive. When such situation arises, the CPU will have to travel a longer path to retrieve the data from the hard drive. This results in sluggish game performance and intermittently ‘hanging‘ of the game. To increase the performance of the game, the foolproof way is to increase the amount of RAM in the system. The more RAM you have, the better the game performance.

The chipset and the RAM

The performance of the RAM is also dependent on the type of chipset used. This is because both Intel and AMD handle the RAM differently.

How does Intel Manages your RAM?

In computers that are using Intel chipset, the processor accesses the RAM via two buses. The first bus is a controller (known as memory controller) that stores the data address in the RAM while the second bus is the data bus that performs the actual transferring of data. (known as the Front Side Bus, or in short, FSB) Whenever the processor needs to retrieve data from the RAM, it will first go to the memory controller to request for the data address, then head to the RAM to retrieve the data. The instruction is then sent via the FSB to the CPU.

How The AMD Chipset Does It?

In AMD, data are retrieved from the RAM in a slightly different way. Since Athlon 64, AMD reinvented the wheel and changed the whole design architecture. They removed the memory controller from the motherboard and integrated it into the CPU. The CPU now has instant access to the data address and is able to retrieve data at a faster rate. This resulted in an improvement of the system performance.

Factors that affect the RAM performance

There are two main factors that affect the RAM performance: its operating frequency and memory space.

Operating frequency

The frequency determines how fast the information can be written to or read from the RAM. The higher the frequency, the faster the information travels between the CPU and the RAM and the better the performance of the system. A point to note, every motherboard has a certain range of frequency that it supports. You can’t simply grab any memory and assume that it will work in your motherboard. You will have to make sure the frequency match up with the bus’s bandwidth as determined by your motherboard.

Memory space

The amount of memory space determines how much information the RAM can store. It is desirable to have as much memory space as possible. In the event that all the memory space are filled up, the overflow data will be written to the hard drive. When such situation happens, you will see that your computer comes to a sudden halt and/or your application suddenly become very sluggish and unresponsive. To increase the performance of the computer, it is advisable to install the maximum amount of RAM that your motherboard can support.

Understanding The Various Type Of RAM

SDRAM (Synchronous DRAM)

In the age of Pentium II or Pentium III computer, SDRAM is the most common type of RAM and almost all systems were shipped with it. Today, the SDRAM has become obsolete and taken over by faster and newer generation of RAMs.

DDR SDRAM (Double Data Rate SDRAM)

DDR memory, or double data rate synchronous DRAM (SDRAM), is a memory technology that does exactly as its name implies – double the rate of standard SDRAM.

DDR differs from SDRAM in that it:

* Can operate twice as fast as standard SDRAM.
* Can lead to significant performance improvements over systems with SDRAM.

Even though DDR modules have the same physical dimension as SDRAM modules, they have different number of pins and notches. Therefore, DDR modules will not fit nor work in an SDRAM system. DDR memory can only be used in systems designed specifically for DDR memory technology.

DDR2 RAM

Both DDR and DDR2 RAM are the improved version of the SDRAM. They are able to transmit data on the rising and falling edge of the clock cycle. The conventional SDRAM can only transmit data on the rising edge. For a certain clock frequency, say 100MHz, both DDR and DDR2 RAM can operate at double the clock frequency, i.e. 200MHz. The difference of DDR2 to DDR is a doubled bus frequency for the same physical clock rate. What this means is that for a 100MHz clock frequency, a DDR2 RAM can achieve a speed of 400MHz while DDR RAM only achieves 200MHz.

DDR2 RAM has 240 pins (compared to DDR RAM 184 pins) and it is not backward compatible with DDR RAM. Generally, DDR2 RAM process much faster than DDR RAM

DDR3 SDRAM

The difference between the latest DDR3 and the DDR2 is the faster processing speed and lower power consumption. The DDR3 RAM can process at a maximum speed of 1600Mbps while DDR2 can only achieve 800Mbps. In addition, DDR3 runs at 1.5V as compared to 1.8V of DDR2.

DDR3 RAM is not backward compatibility with DDR2 RAM. While both of them have the same number of pins, the key notch is placed in a different position to avoid the confusion between a DDR3 and DDR2 RAM.

ECC Versus Non-ECC Memory

ECC (Error Checking and Correction) is an algorithm for checking the integrity of data stored in DRAM memory. If it detect or sees an error passing through the memory, it will do its best to fix it on the fly. For this to happen, special circuitry and an additional memory chip is put onto the memory module. This allows the algorithm to run so that it can test the accuracy of data as it passes through the memory.

Memory that has ECC technology looks for errors in data traveling through the memory. For gaming this is really not necessary because today’s memory is pretty reliable, and few errors are generated in normal use. ECC is designed more for mission-critical business servers or architectural modeling where extreme reliability counts.

Non-ECC doesn’t note or correct any errors. It is the same memory but without the error checking and correction technology. The reason they make both is because the majority of the computers running don’t need to be that exact or precise. In word processing, for example, any small error in memory has no real effect.

ECC memory is also more expensive than non-ECC memory. There is no need to spend extra money on buying ECC memory because you gain no real results in the PC game world. It is a common opinion that when building your own machine that you buy non-ECC memory because otherwise you are just wasting money.

How to Choose a Gaming RAM?

Here are some things that you need to take note of when choosing a gaming RAM.

Motherboard

As mentioned earlies, different type of RAM uses different type of slot. Your motherboard won’t be able to support DDR/DDR2/DDR3 concurrently. Before you buy/upgrade your RAM, it is important to find out which type of RAM your motherboard supports, how many slots are there and what is the maximum memory space that it supports.

Memory Size

Of course, the bigger the memory, the better it is. Most motherboard nowadays allow you to add RAM up to 4GB in size. For a gaming computer, we recommend no less than 1GB of RAM, perhaps even going up to 2GB if your budget allows. If cost is a factor, it’s fine to stop at 512MB, but that really is the minimum you should go to. When you have enough cash, grab another 512MB for your system.

Single or Dual Channel?

Dual-channel memory is a term that’s used to describe a matching pair of memory modules installed in a dual-channel computer system.

The term, however, can be a little misleading because the memory modules themselves are no different than the memory used in any other computer. Rather, it’s the motherboard that’s different.

In a dual-channel system, the computer motherboard is designed to work with two memory channels instead of one. This allows the system to handle memory processing more efficiently by using the theoretical bandwidth of two memory modules at a time, reducing system latency time and making the whole system faster.

The key to taking full advantage of dual-channel memory operation is installing a pair of matching memory modules (i.e., same size, speed, etc.) at a time. The modules must be identical to each other for dual-channel operation to perform correctly.
When Getting Two Or More RAM Modules…

Brand

If you are getting two or more RAM modules for you PC, ensure that all your memory is of the same brand. Mixing and matching does not always yield the best results. Sometimes they won’t even boot up together, or they cause continual system crashes. Memory is very specific; the slightest difference in the memory chips can cause you problems. Although this is not always the case, it is not recommended. The potential hassle aren’t worth it.

Speed

Try to keep all the memory the same frequency. Don’t buy one chip of PC4200 and another of PC5400. If you do this, the data transfer speed will be limit at PC4200 and you are wasting your money. In the worst scenario, the system might crash since the slower RAM is not able to catch up with the faster RAM.

source: http://www.build-gaming-computer-guide.com/the-complete-guide-to-choose-a-gaming-memoryram.html/1