Cas Latency or Timing Definition

The simplest way to think of cas latency (or timings) is by associating it with how much delay your ram will have. Timings represent the gap between the processor sending information to the RAM and the RAM responding to it. High cas latencies will result in slower RAM.

You can expect that as memory becomes faster it will naturally have higher timings. For example, memory with a speed of 1066 Mhz will likely have a cas latency of 5-5-5-15. Whereas, memory with a speed of 2133 Mhz will possibly have a cas latency of 9-11-10-28. Aim to find RAM with a high speed first. Then focus on finding one with the lowest cas latency.

Video Card Dedicated Memory Amount

Video card dedicated memory is RAM that is embedded into the video card for its use only. Having more memory helps games with larger textures, higher resolutions and so forth to achieve better frame-rates. This memory is completely separate from the operating system's memory. Both are necessarily for smooth performance. Dedicated memory can range anywhere from 512MB's to 4GB's on a modern desktop computer.

RAM Video Tutorial

How to Find a Good Hard Drive

A hard drive is one of the easiest computer parts to learn about. In short, it's where everything is saved on the computer! Now for the longer explanation.

The amount of space that is on a hard drive can range from a several gigabytes to a few terabytes. You can learn more about these terms here. A typical size nowadays is around 250 gigabytes or higher. I usually try to aim for 500 gigabytes or more. Is space all that matters with a hard drive? Not exactly. There are other big factors to consider that affect the performance of the computer. We'll look at some of these.

Above is a hard drive I found that I would consider an excellent choice. This hard drive was made by Western Digital. This model claims to have 500 gigabytes of memory. In reality, only expect to have 465~475 gigabytes. They never give as much as they say.

A hard drives RPM speed is also very important. Hard drives have platters inside that rotate at fast speeds. The faster it rotates, the faster you will load and save things. Some standard RPM speeds are 5400, 7200, 10000 and 15000. 5400 is what you find in a lot of cheaper laptops. 7200 is the standard speed in desktop computers. 10000 and 15000 are very fast speeds that many enthusiast enjoy but they can get kind of pricey.

The example then says that it is SATA 3.0Gb/s. This is the port used to plug the hard drive into the motherboard. The most current version of SATA runs at 6.0Gb/s. 6.0 isn't needed as much for regular hard drives as it is for solid state drives. These are talked about in this article.

The cache for this hard drive is listed at 64MB. Cache is RAM specifically made for the hard drive but cache is faster then regular RAM! Because it is built into the hard drive it has less latency and runs much quicker. I try to find hard drives with 64MB of cache but 32MB is okay also.

Things to Keep in Mind
These are the most important things to know but before making the purchase, check the benchmarks previous buyers have posted in reviews. Check how many MB/s the hard drive runs at. Lots of times hard drives run around 70~130 MB/s. Don't settle for anything too low.

Although companies like Western Digital and Seagate have a good reputation for making hard drives, remember that even these companies can make lemons. Always search for hard drives based by user reviews after narrowing your search. After reading these reviews, you will know what to expect for pros and cons.

What is RAM?

RAM is an abbreviation for "random access memory". It is also referred to as "memory". RAM is where everything goes to when it is loaded. You probably noticed how long it takes for everything to start up at first. That is because the hard drive has all of this information. The hard drive is a huge pool of information that can be saved even when the computer is turned off. The problem with the hard drive is that it's slow. To deal with this slowness, the information needs to be loaded into the RAM. RAM holds a much smaller amount of space than hard drives but is many, many times faster. Once the information is loaded to RAM, everything will run smooth. RAM, however, cannot save information after the computer is turned off. This is why the computer will need to go through the start up process again after you turn it on.

When most people hear about RAM, they think about how much space it has. This is usually measured in gigabytes. Common amounts of space are anywhere from 2 GB's to 16 GB's. A good amount now days is around 2 to 8 GB's. If you have any less, you'll bottleneck your computer so it won't run well. There is little point to having more than 8 GB's because you probably won't use it anytime soon. You can buy multiple sticks of RAM depending on how many slots you have in your motherboard. Your motherboard will have limitations on what it can hold. It is important to find this out first.

Another important thing to look out for too is the speed of RAM. Most people don't think to check for this but the whole point of having RAM is that it's fast! A common type of memory is DDR or double data rate. This is currently generation of this is DDR3. The newer generations run at faster speeds. RAM speeds are measured in megahertz or MHz. Some standard speeds may be anywhere for 1066 MHz to 2000 MHz. Both the RAM and the motherboard have to support the same maximum speed. Otherwise, the speed of the RAM will run at the lowest common supported speed. An example of this is provided below.

Another thing to check is the RAM's cas latency. Latency is how many clock pulses there are between the RAM sending the information and the computer being able to use it. It is important to have as few clock pulses go by as possible. Unfortunately, the higher the frequency, the higher the latency will probably be. This is simply something you accept as you purchase faster RAM. Just remember to search for RAM with the highest frequency first and after you've identified the frequency you want find the lowest cas latency as possible.

This example came from Newegg.com. Generally when searching for RAM, I like to sort the results by rating. This puts the most popular RAM toward the top. In this particular example, there are to sticks totaling 8 GB's of space. 2 x 4GB tells us that there are two sticks and each stick has 4 GB's. The next part tells us what kind of RAM it is. 240 pins is the standard for desktop computers. DDR3 is the newest kind of RAM. 1333 is the amount of megahertz the RAM runs at. This is a very important number to know. You want as many MHz as you can get. Cas Latency and Timing tells you how much delay the RAM has. Keep this number as low as possible. It also states that it is a dual channel kit. Try to also find a motherboard that is dual channel. These are the factors to look at when choosing RAM.