RAM Memory
In a computer, the memory called RAM is short for SD-RAM, meaning Synchronous Dynamic Random Access Memory. This is the short-term memory of your computer. Before and after data is passed to the CPU, this information is stored in the RAM. It holds the information currently being worked on before it is committed to a hard drive or disk or other data storage device.
In fact, if your computer shuts down with open documents, the information you will lose is what was in the RAM memory. Indeed, unsaved changes are stored in the current working memory of the computer, for as long as it is powered. Before shut down, this memory has to be transferred from the RAM to the hard drives for you to keep your data.
Before you start building your computer, make sure that you first choose the CPU and motherboard. This is especially important because they will determine the speed, voltage and type of RAM you need.
Here are are the important aspects to consider to find the best possible RAM for your board.
What Specs are Important for RAM?
RAM Capacity (Gb)
The capacity is the quantity of memory that each stick can hold in Gigabytes (Gb). You should currently aim for 8 Gb or 16 Gb memory sticks. A common mistake is to buy a lot of lower sizes because it's cheaper. But when it comes time to upgrade, they will all need to be replaced with bigger sizes. The common formats are the following:
- 4x 4Gb (Obsolete)
- 2x 8Gb (Recommended)
- 1x 16Gb (Recommended)
DDR Memory Type
The first thing to consider when buying RAM is the DDR type. DDR means 'Double Data Rate', and each iteration adds new levels of speed, so the higher the better. The next DDR standard to follow is the DDR4 memory and this is what you should look for to maximize your investment in time. DDR influences the speed of your memory considerably, so it is not to be overlooked. You can find more about DDR types in this article at www.pcmag.com.
- DDR1 (Obsolete)
- DDR2 (Obsolete)
- DDR3 (Current)
- DDR4 (Recommended)
RAM Clock Speed
The clock speed (in the thousands of Mhz) is synced with the speed of your CPU and motherboard. The listed speed is the speed at which the memory was tested and at which it is recommended. It will determine the maximum speed of the transfer between the processor and the memory and the overall speed of the motherboard. Use the highest speed you can find, as specified in the motherboard specifications. And unless you are already experienced with overclocking, try to find a speed that is not listed as overclocked. This is often marked as 'OC' of 'factory overclocked' in the technical specifications or the name of the product.
Compatibility List
You can also consult the list of compatible memory, provided with every motherboard. You can also find such 'motherboard compatibility lists' on the board manufacturer website to see which specific memory sticks and brands are compatible with your board and make sure that your purchase will be compatible. This list will save you the time of making sure the voltage and speeds of the CPU and RAM are compatible.
CAS Latency Timings
The other factor is the CAS latency Timings (ex. 8-8-8-24). The CAS latency is comparable to the response time, so a lower timing is better. You will see a better performance improvement in lowering the timings, than to buy RAM that has a higher clock speed. The bigger the memory, the lower the latency. You can find more information on CAS latency timings at www.hardwaresecrets.com if you'd like more technical details.
RAM Voltage (V)
The voltage for the RAM must be provided with extreme accuracy by the motherboard, so make sure it is on the compatibility list.
However, this voltage is mainly determined by the type of processor you are using. Every generation of CPU has different maximum voltages requirements. This voltage usually goes down with each generation of CPU. Make sure to check the voltage requirements for the RAM, on the technical specifications for your CPU to ensure compatibility.
- 1.65V (DDR3) - Obsolete
- 1.5V (DDR3) - Older
- 1.35V (DDR3) - Older
- 1.2V (DDR4) - Current / Recommended
Form Factor
Most rams have similar sizes, however laptops use a different kind of memory, that is smaller, but incompatible with desktop computer memory.
You should preferably find RAM sticks that come with heatsinks to dissipate heat better. This will improve durability and efficiency on your RAM during heavy use. However, try to favor low-profile heatsinks to allow the RAM sticks to fit under bigger CPU fans. We recommend this, otherwise you risk being unable to use 2 or more slots of RAM on your motherboard. If you have a very small computer case, then you may opt for sticks without heatsinks. However,
Grouped RAM Kits
Depending on your motherboard, your system may require to use multiple identical RAM sticks at the same time. For example, dual-channel systems will use 2, while quad-channel boards will use 4. This determines the number of RAM sticks you need to buy in grouped kits/packs.
In every case, it is always preferable to buy groups of identical RAM sticks right away. They are usually sold in packs of 2 or 4, and these are not just for upsell. These are components that have been tested to function properly together. To maximize your system stability, you should always have only RAM of the same type, speed, brand, voltage and latency. Incompatible RAM will lead to crashes or prevent boot altogether.
In case you plan on upgrading your memory a year or two down the line, it might be difficult to find exactly the same model numbers and specifications. Models tend to change stats quickly and evolve in availability during their lifecycle. Sometimes, very old RAM can even become more expensive than faster RAM, after a while. So go ahead and fill up that motherboard right away. Otherwise, you'll need to buy RAM that has exactly the same specs, and still on the compatibility list of the motherboard.
Error Correction (ECC) Memory
ECC or 'Error-Correcting Memory' is a type of memory that corrects itself of the most common RAM errors. Even in RAM errors seem unnoticeable to the user, it requires repeat operations, and it can create file corruptions. Self-correcting memory avoids those repeat operations and possible corruptions, for better efficiency and reliability.
It is only used for server computers and Xeon processors that need a very high level of optimization. Of course, ECC memory is more expensive for the same speed, because of the fact that server hardware always come with better longevity and extended support. If you are absolutely intent on building a dual-processor system, then this will be what you need.
However, this type of memory will not be compatible with usual mainstream processors, so we do not advise you to use ECC memory for your home computer builds. Instead, look for the term 'non-ECC' memory instead. You can usually find this information in the title or specifications of the product. You can find out more about ECC memory on this page.
RAM Brands
Here are good brands of RAM:
- Corsair
- G. Skill
- Mushkin
- Kingston
- OCZ
Price
You can expect to pay between 75$ and 150$ for each stick of good quality, fast and reliable RAM memory.
Summary Chart
Connected Components
Go to the 'computer hardware' table of contents:
Guide on Finding the Optimal Computer Components
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