Getting your RAM (random access memory) right is a crucial part of any PC build. But how much do you need and what are the things to look for? Let's find out.This guide will focus on desktop memory rather than laptop.

What does RAM do?

RAM is essentially a storage device, but unlike a hard drive, the data is only held within the device for short periods of time. It is the fastest storage medium in a computer and its purpose is to enable you system to multitask more efficiently. If your CPU had to store data on slower mediums like HDDs and SSDs, your whole system would take much longer to perform what you ask it to do.

How much do I need?

This question, as with many others where computer are concerned, is answered simply with "it depends".If you are building a computer from scratch, nowadays, the minimum I would recommend is 8GB and only then if you are on a very tight budget. If your system is going to be used for gaming then you would want to up that to 16GB, or even 32GB if you want future-proof your system for a few years. For workstations that deal with heavy workloads, 32GB should be your minimum.

How many modules should I get?

If you want 16GB of RAM, you could be tempted to buy one 16GB module. Makes sense, right?

Well, if you did that, you would be sacrificing something called dual-channel mode (or quad-channel if you went for 4 x 4GB). Buy buying two 8GB modules, you get the same amount of memory but the bandwidth is doubled. Rather than only having access to one stick, your processor can now access two simultaneously. This offers some advantages, such as reduced CPU usage and some frame rate improvements

Choosing the right type.

Unless you are dealing with an old system, DDR4 (Double Data Rate 4) is the current standard for RAM. It is the 4th generation of the DDR family and offers greater data transfer rates and capacity per module, as well as running on a lower voltage, making them more energy efficient.If you have an older motherboard, it may use DDR3 modules. You cannot use DDR4 on these boards as they simply won't fit.

What speed should I buy?

When choosing RAM, you should look out for its speed rating, in Megahertz (Mhz). A module of 2400Mhz RAM will be slower than a stick rated at 3200Mhz, for example. You must make sure that your motherboard supports the frequency of the RAM you choose. You can do the buy checking the specifications of your motherboard before buying.

Anything else?

Actually, yes! The final thing to consider when it comes to performance is the CAS (Column Access Strobe) latency. It is the delay between the CPU making a request and the RAM responding.

To find the CAS of your RAM, look for a string of 4 numbers listed in the name, in this format:


The first number is you CAS. What you want is the lowest number possible. DDR4 has a range of 15 to 19. The lower the CAS, the higher the price.

As an example of what CAS means, let's take a look at the formula needed to show you the latency of your RAM:

(CAS latency/RAM clock speed) x 2000 = latency in nanoseconds

If you have a CAS of 16 and a speed of 3200Mhz, your latency would be:

(16/3200) x 2000 = 10 nanoseconds.

Compare that to a CAS of 19 x 3600Mhz:

(19/3600) x 2000 = 10.5 nanoseconds.

Despite having a faster clock speed, the 3600Mhz, module is slower than the 3200Mhz module, all thanks to the CAS. Hopefully this demonstrates why it is an important consideration.

Do you like bling?

RAM modules come in all sorts of shapes and colours. If you like RGB lighting, you can get some really nice sticks that are controllable by your motherboard. This comes at a small premium, but not too much.

And finally...

The final consideration is the height of the modules. You need to make sure that you have enough room for the modules you choose, especially if your system has a chunky CPU air cooler. If you are tight on space, you can buy low profile modules that will fit in the tightest of spaces.

Can I upgrade my RAM?

So there you have it, our RAM guide is complete. You may now be itching for a RAM upgrade...

RAM upgrades are simplest thing to do and can offer huge boosts in performance.

Hopefully, the guide will give you the confidence to go out and buy exactly what you need, but if not, feel free to get in touch and we will help you out.