Computer Memory Buyers Guide
What is RAM / Memory ?
System memory, or more accurately RAM (Random Access Memory) is used by PCs to temporarily store data before it is permanently stored on a storage drive. The more memory your system has the more applications it can run at once and the faster those applications will run.
With hundreds of models of memory available at any one time, it is important that you choose memory that is compatible with your system. It is also worth considering what you are planning to use your PC for, as different games and applications will benefit from varying amounts of memory.
While there are dozens of different memory manufacturers, Scan recommends CORSAIR MEMORY as it is extremely reliable and available in a wide range of models.
Which type of memory is right for my system?
While there are various types of memory available, the vast majority of PCs sold in the last few years support only one type of memory – DDR4. This stands for Double Data Rate, with the ‘4’ meaning this is the fourth generation of DDR memory. Don’t panic though, if you have an older system that isn’t compatible with DDR4, Scan still stocks a wide range of DDR, DDR2 and DDR3 memory.
Things to Consider with Memory
|Size||The next thing to consider is what size memory you should be looking at. Most desktop PCs require memory sticks, known as DIMMs, each with 288-pins on them. However, if you’re trying to upgrade a laptop it will require SODIMMs, these are a bit stubbier than standard DIMMs, and have 240-pins.|
|Channels||The second decision you need to make is selecting a pack of memory with the optimum number of channels. All modern CPUs are capable of running multiple DIMMs together to boost performance. Most CPUs support dual-channel memory, so will perform best when you install the memory in pairs; however, some high-end CPUs support quad-channel memory, so will perform best when you install the memory in multiples of four. Although you can buy multiple individual DIMMs, it is better to buy a dual-channel or quad-channel kit, as the individual DIMMs in the pack will have been tested together by Corsair.|
|Speed||The final consideration is the speed of the memory. While there are a number of factors that determine memory performance the most important spec to look out is the speed, which is displayed as the frequency in MHz. A word of caution, you won’t get the full benefit of high frequency RAM unless you go into the motherboard BIOS and do some tweaking. This is because not all CPUs support super-fast memory, so MOTHERBOARDS set the memory to run at a safe neutral speed out of the box. Think of it liking starting a car engine in neutral rather than first gear. For most CPUs, this neutral speed is 2133MHz, so if you’re intending on buying much faster memory, don’t forgot to configure the BIOS according once you’ve installed your new RAM.|
|Aesthetics||Now that you know which type of memory is right for your system its worth quickly pointing out that you also have a choice of the appearance of the DIMMs, including the latest fad, memory with built-in RGB lighting.|
How much memory do I need ?
Installing more memory in your PC or laptop is an easy way to boost its performance, however, not all applications and games will benefit from having lots of memory. The following tables shows several examples of different uses for a PC, giving examples of how much memory will give you the best bang per buck. You can of course install more memory, but the aim of this guide is to show you the optimum configuration so you don’t spend more than is necessary.
Home & Office
Web browsing, email, Youtube etc
Run several applications at once
Edit photos in Adobe Photshop
Games like Minecraft and DOTA 2
Games like ARK and GTA V
Live streaming games
Simulations, visualisation with large models and textures
Small sound libraries
Mid-size sound libraries
Large sound libraries
Working with FullHD video
Working with 4K video
Working with 4K or higher video
Memory is also critical to the performance of a server, but because these computer systems are normally active 24\7 they don’t use standard DDR4 memory. What most people normally refer to as standard DDR4 is technically known as unbuffered or unregistered memory, in which the memory controller in the CPU talks directly to the memory chips on the DIMMs.
In contrast, most servers require what is known as ECC memory. ECC stands for Error Correcting Code, and means that the memory can detect and fix data corruption on the fly. This does have a very small performance penalty, but the data stored on most servers is so important it is generally considered not worth the risk of losing anything through corruption. ECC DIMMs are normally very easy to spot as they have an extra chip in the middle of the DIMM.
To make things more complex there are two types of ECC DIMM, regular unbuffered/unregistered DIMMs and a more advanced type known as buffered or registered DIMMs. ECC unbuffered DIMMs are most commonly used by entry-level servers with a single CPU and four DIMM slots on the motherboard. ECC registered DIMMs are normally required for servers with more than one CPU, and have extra circuitry known as a register which reduces electrical load, enabling large numbers of DIMMs to be connected to the memory controller.
At the top is ECC unbuffered DIMM, pictured above an ECC registered DIMM, with the extra register chip clearly visibly in the middle of the module.
Standard unbuffered memory won’t work in servers and similarly neither type of ECC memory will work in most DESKTOP PCs, so we list server memory in a separate category on the Scan website.