How to Choose Your Parts, Part 4: RAM
How to choose your Parts: RAM
Greetings! Welcome to the Micro Center Community. By now hopefully you’ve read through the first three guides. If you haven’t, go do that! If you have, then you’re probably in the process of putting a custom build together and aren’t sure exactly what to look for. For Part 4, I’ll be going over how to choose your RAM. Like the motherboard guide, this one is going to be a little more “conceptual” without specific recommendations for a kit. Instead, I’ll go over what sorts of specs/features to look for based on your personal needs.
As always, some key questions:
- What are you using this computer for? This is the most important question when it comes to choosing your RAM. For any given task, you only need so much memory and what you’re doing will determine how much you should get.
- What kind of motherboard and processor do you have? While rare, compatibility issues with RAM do exist and that depends on your board and CPU.
- Are you overclocking your memory? If you’re a person who’s really into memory overclocking, you’re going to need to pay special attention to what RAM kits you’re going for and what type of overclocking capabilities it has.
The Basics and Some Terms to Know
RAM - stands for Random-Access Memory, also referred to simply as “memory” (I’ll use these interchangeably throughout this guide). RAM is basically used as a temporary space to read and write data for your computer for active applications and windows. CPUs are much faster than a hard drive or SSD and if it were only reading/writing directly from the drive on your computer it would be very slow. Instead, we use RAM as a high-speed access point for your CPU to use data that it needs.
DIMM - stands for Dual In-Line Memory Module and is the technical term for a stick of RAM.
Memory Channels - You may see kits labelled as single-channel, dual-channel and quad-channel. That’s just because the kits will come with one, two or four DIMMs. Memory channels are actually a feature on your motherboard, not the memory itself. The simplified explanation is that each DIMM has certain amount of bandwidth available to send data through. More channels add more bandwidth, and in certain situations this can lead to better performance (more on that later).
IC – stands for Integrated Circuit, sometimes referred to as the RAM “die.” The integrated circuits on a DIMM are the actual “memory” part of the RAM, so to speak. They’re the physical part that performs the function of storing and sending data. The important thing about ICs is that RAM manufacturers typically do not manufacture the ICs, they’re sourced from other manufacturers. This is an important note for compatibility reasons (more on this later)
How much memory do I need?
This is where question #1 comes in. What you’re using the computer for is going to determine how much memory you need.
One misconception some people may have is that more memory means your system will be faster, which isn’t really true. It would be more accurate to say “more memory will improve performance if you’re over-taxing your existing memory.”
When your RAM is fully saturated the computer starts placing some of that burden onto the disk (SSD or hard drive) in your system. This will have huge performance impacts because disks are MUCH slower than memory. Even if you have the fastest SSD in the world, if any resources that would normally be handled by RAM are swapped onto the disk they will be handled far slower.
In other words, if you don’t have enough memory, it will slow things down, and if you have enough, it won’t. Any more than that is just extra leeway.
8GB of RAM is our minimum recommendation for general use, i.e. basic web browsing and office work. If you’re just checking your email, watching Netflix, and typing up word documents, you don’t need a ton of RAM, but with how RAM hungry browsers these days can be (looking at you, Google Chrome) less than 8GB will usually not be enough.
If you’re a gamer, 16GB of RAM is the recommendation. It leaves you enough wiggle room for the game itself as well as any other potential windows or processes that may be running on the system. While you can get by with 8GB of RAM, you’ll have to be careful about running any other applications because some games are to the point where 8GB of RAM is the minimum amount recommended. 16GB is also a good starting recommendation for workstation type applications like rendering and graphic design.
More than 16GB would be overkill unless you have a specific use case for it with very memory intensive applications, such as high-resolution video and photo editing.
First, you need to match the RAM socket to the kind of motherboard you have. If your motherboard has DDR4 memory slots, get DDR4 memory. RAM slots are not backwards compatible, you can’t use a DDR3 RAM kit with a DDR4 board. They have to match exactly.
Second, even with the right slot, there can still be compatibility issues with specific RAM kits and motherboards. First and second-generation AMD Ryzen had a reputation for being picky with RAM, but third generation Ryzen has mostly rectified that issue. Intel is generally pretty reliable when it comes to RAM compatibility as well.
Every motherboard has a QVL (qualified vendor list) of memory kits that have been tested and confirmed to be compatible. These lists should be available on the motherboard’s support page on the manufacturer’s website. If you can, it’s best to try and stick to memory on that list to ensure you won’t run into a compatibility issue. However, even if the RAM isn’t on the QVL, it will probably still work, it’s just not a 100% guarantee.
One last thing when it comes to compatibility: when putting RAM in your system we always recommend matching DIMMs exactly if possible. If you run faster memory with slower memory, the faster DIMMs will be adjusted to match the slower ones and you lose performance. Even if RAM lists the same clock speeds, RAM manufacturers use different ICs for their various of kits of RAM available on the market. If the ICs don’t match, things like latency and timings will not match either. Mismatches on any specs with RAM can lead to performance loss and stability issues.
What kind of RAM should I get?
This is… kind of complicated. Before we talk about what RAM you should get, we need to have a little discussion about memory overclocking. A lot of people don’t realize how much of an impact memory can have on your experience, especially in gaming, and in order to take full advantage of your memory, you have to overclock it.
By default, memory is going to run at a certain base clock speed when it’s installed into a motherboard. If you want it to run at faster speeds (or the speed it’s actually rated for) you have to overclock it. In order to overclock your memory, you have to enable a setting in your BIOS. For Intel boards the setting is called XMP (eXtreme Memory Profile). For AMD boards it can be labelled something else, such as DOCP, EOCP, and more, depending on brand.
This is going to be a pretty basic overview. Memory overclocking can get very complex depending on how deep you want to go down that rabbit hole and a really in-depth guide would be better reserved for its own post or series of posts. At the end of the day, most people don’t want to put in hours and hours of work tweaking individual timings for their memory and would rather just set it and forget it. I’m going to assume that you’re a person who would like to install your memory, turn on XMP and then call it a day.
Let’s use this kit of memory as an example:
This is a set of G.Skill Ripjaws V DDR4-3200 CL16 memory. DDR4 is the socket/pin layout, 3200MHz is the frequency, and CL16 is the CAS Latency. In a very general sense, higher frequency and lower CAS Latency is better. Higher frequency means the RAM can read/write more data in a clock cycle. Latency is the time it takes for a memory operation to take place.
Platforms respond to frequency in different ways. AMD’s third generation Ryzen processors scale very well with high speed memory, the sweet spot being 3600MHz. AMD CPUs are also a little more sensitive to lower-speed memory. Intel on the other hand doesn’t scale as well, and after 3200MHz you generally get diminishing returns, but will have less performance loss if using lower speed memory. This isn’t a good or bad thing, just reflective of their different designs.
Latency in particular can have a big effect on frame-times in games. Where this is really important is for very high-refresh rate gaming: if the latency on your RAM is slow it can cause stuttering and FPS issues. CAS Latency goes hand-in-hand with the clock speed, and there’s a simple formula you can use to figure out the relative performance: CAS L/Clock Speed x 2000 = effective latency. For our 3200 CL16 kit, that would be 16/3200 x 2000 = 10ns (nanoseconds). Generally speaking, the lower that effective latency number is, the better. 3200 CL16 memory is a good general standard to go by for mid and high-end gaming systems.
The frequency/CAS Latency listed on RAM specs is a pre-set XMP/overclocking profile that was tested by the manufacturer that will be stable on a wide variety of systems. When XMP is turned on, you can use it to automatically load that default overclocking profile and gain a lot of speed on your RAM without any work. That said, your CPU and motherboard are both very important for XMP/memory overclocking and the default XMP settings may not be stable in your configuration. Most of the time that’s not a problem, but it can happen.
Single vs Dual vs Quad Channel memory
As mentioned earlier, you’ll see memory kits labelled single or dual or quad channel, but memory channels are handled by your motherboard. Most every modern motherboard will support dual channel. High-end boards may support quad channel.
If you were to do research online, you’ll probably come across a lot of conflicting information. Some people would say it doesn’t make a difference for the average user and some would say you’re unnecessarily gimping your system if you don’t go dual channel.
More channels mean more bandwidth for data to pass through. In some situations, it won’t matter. In other situations, it can actually have a very large effect on performance especially in certain games. With how RAM is currently priced, you don’t really pay extra for having one DIMM vs two. Unless you already have a plan to do add more memory to your system later on, I would say there is no reason to not go with a dual-channel configuration.
Quad-channel will only make a difference in certain very memory intensive professional applications, the average user or gamer will probably not get any benefit from it.
And that concludes part 4! Hopefully you learned something new about RAM that helps you figure out what works best for you, and as always, feel free to comment below or make a post if you have any questions (and make sure you go read Part 5)!