DDR5 vs DDR4 Memory, Differences & Should You Wait?
DDR5 RAM is coming, and if you have been thinking about building a new PC anytime soon, then you’re going to have to make a decision! Should you wait and hold out for DDR5 or go with DDR4, you will have to decide because they are not backward compatible.
In this article, I will try and give you all the information you will possibly need about making a decision, including the differences between DDR5 vs. DDR4 and when you can expect DDR5 to come out.
Let’s get into all the significant differences between DDR5 and DDR4.
Memory Bandwidth is basically how fast data can be retrieved from or put onto the memory stick. With the maximum standard specifications, DDR4 has a maximum bandwidth of up to 3.2 gigabits per second per pin.
But DDR5, with the maximum specifications, has up to 6.4 gigabits per second per pin. However, at first, it will probably be around 4.8 gigabits per second. It is still a 50% increase, but eventually, as RAM improves, it will get up to 6.4 gigabits per second, double the DDR4.
DDR4 and DDR5 both have the same number of data pins, so that’s not going to make a difference here. However, the frequency of the memory is going to make a major difference. That’s the reason for the difference in memory bandwidth between the two.
The standard DDR4 has a frequency range of between 1600 megahertz and 3200 megahertz, whereas the DDR5 is double that. The frequency ranges from 3200 megahertz to 6400 megahertz, but the eventual maximum number will probably be even higher than that.
Because with DDR4, the maximum spec is just up to 3200 megahertz, but if you visit Newegg or Amazon, you may see RAMs up to 5000 megahertz. That’s probably down to overclocking. So, technically 3.2 gigahertz is the max standard spec for DDR4, but of course, it is higher.
So we’ll probably see much higher than the 6.4 per pin on DDR5. I’ve seen people saying about up to 8400 megahertz for DDR5. But the main takeaway from all this is DDR5 will be capable of higher frequencies and, therefore, higher memory bandwidth overall.
Power Management Structure
With DDR4, all the power management of the RAM slot is done on the motherboard itself. Whereas on DDR5, it’s going to have an actual chip called a PMIC (power management integrated circuit) on the chip itself. Each chip will be able to manage its power.
So, theoretically, this should mean that the RAM is going to be more power-efficient. For example, if an individual RAM dim module requires more power at a certain moment, it will get that power without increasing the power to all the RAM at once.
At least that is my understanding of it, and also, I’m not 100% sure how this will affect overclocking. You can do that right now through your bios on your motherboard. I’m not sure if you will be able to do that or not. We’ll see.
Now you may know that you can get dual-channel RAM, quad or channel RAM with different slots in the motherboard. This means that the CPU can go out and access different pieces of data within each channel.
If there’s just one channel, the CPU can only get one piece of data at a time. It’s kind of like having multiple cores in a CPU, where you can do multiple stuff at once as opposed to just one at a time.
Each DDR4 module has just one channel per stick, and it’s made up of 72 bits (64 data bits and 8 bits for error-correcting). However, with DDR5, each RAM module or stick has two channels, and each of those channels is a 40-bit bus meaning it’s going to have 32 bits of data pins and eight for error-correcting pins.
So, both DDR4 and DDR5 have the same amount of data pins. However, with DDR5, you’re going to have two channels instead of just one. As I said, DDR4 already does support multiple channels, but with DDR5, you can have two channels on each stick.
This means if there are two different pieces of data, one in each channel that the CPU wants to access in different parts, it can do both of those without having to wait for one or the other. So each RAM stick should be a lot more efficient.
I assume that we will get a lot more potential channels in DDR5.
This is a little bit technical, but I will try and explain it as best and simple as I can because it is pretty important. DDR4 has a burst length of 8, whereas DDR5 has a burst length of 16. But what does that mean?
This did take a little bit of research on my part, and I’m not a super expert on this. I could be a little bit off in some parts, but this is my understanding, and hopefully, it will be helpful.
The data on RAM is stored in arrays which are just groups of rows and columns, with each combination of the two having a bit. When a certain piece of data in the form of a bit needs to be retrieved from the RAM, it will first activate a row that prepares it to be read.
After a specific row is activated or opened, then one bit from each row can be read from all the arrays simultaneously and then all of that data gets put into the output buffer to be sent to the CPU. However, this process of opening and activating a row is relatively slow.
So, if you’ve ever looked at RAM timings, the Trcd is actually how long it takes to open a row. You’ve seen that number before, and if there’s a different row already open, it’s going to take even longer because that row must be closed first, and that amount of time is the Trp.
So, instead of doing this every single time, you have to read one single bit. The row is already activated for a short amount of time, so the RAM will go ahead and read multiple columns within that row back to back.
So, if there is more data in that row that needs to be read, it will be way faster and way more efficient. The maximum number of bits the RAM can read from a row while it’s open before needing to reopen is called the burst length because it takes a burst of data at once instead of just getting each bit one at a time.
So, while DDR5 is going to have very similar timings and latency numbers as DDR4 because it’s going to have a longer burst length in this case, it means that in more situations, it’ll be able to read more data without having to have those delays happen as frequently meaning that overall it’s just going to be able to access faster speed.
The final major difference between DDR4 and DDR5 is the maximum capacity. This is a pretty fun one because DDR5 has up to four times the maximum density of data as DDR4 specifically.
The DDR4 has up to 16 gigabits of data per die, an individual tiny memory chip on the memory stick. However, the RAM manufacturers can put multiple of these dies on each side of the RAM stick.
This is called stacking, and typically, manufacturers can put about eight of these on each side, which is called a dual-rank. When you multiply all these together, you get a total of 256 gigabits which is 32 gigabytes as the maximum amount of RAM you’re going to be able to fit on one stick of RAM for DDR4.
With DDR5, you can have up to 64 gigabits of data perdie. Multiply the capacity of all the chips on both sides, and you get 128 gigabytes maximum per stick. However, keep in mind that it will take time for the manufacturing process to build up to that maximum density.
In the beginning, when DDR5 first comes out, you’re probably going still to see a maximum individual stick at about 32 gigabytes, then it will grow over time.
FAQ & Guide
When is DDR5 coming?
Now that you know the differences between the two generations, you might be wondering, when can I get this?
The DDR5 already exists, but right now, you can see it in high-end smartphones like Samsung Galaxy S20. Samsung is also making their own RAM to integrate it into their phones, and they’re making the chips too.
The RAM that’s for actual computers and servers is expected to roll out in the third quarter of 2021. But just because RAM manufacturers start making DDR5 RAM doesn’t mean you’re going to be able to use it on your PC.
That’s because we need to wait for AMD and Intel to make CPUs, chipsets and motherboards that support DDR5. With AMD, some leaked internal memos reportedly suggest planning to support DDR5 and USB 4.0 in 2022. That’s apparently when their next-gen Zen 4 microarchitecture is released.
That is a long way off because Zen 3 architecture was just released a few months ago. And with Intel, some reported leaks show that it’s likely that their 12th generation Alder Lake CPUs will support DDR5.
But again, this could take a while because even the 11th gen rocket lake CPUs are not even out yet at the time of writing this article. It is likely to be released on March 30, 2021. So it’s possible that Alder Lake will be around the second half of 2021.
Looking at these scenarios, it seems like the earliest you could get a DDR5 computer is around the end of 2021 or with AMD in 2022.
DDR5 vs DDR4: Should You Wait?
Now it’s the decision time, whether you should get a new PC or wait for DDR5. Well, there are a few things you need to consider. First of all, when DDR5 first comes out, the difference between DDR4 and DDR5 is not going to be as significant.
That’s because RAM manufacturers get better at producing better RAM over time. Just like DDR4 right now is way better than it used to be when it first came out. Yes, DDR5 will still be significantly better than DDR4, but the price will be much higher at first with minor differences than down the line where DDR5 becomes more affordable and improves.
The next thing you need to consider is how often you intend to upgrade to a new PC. If you’re like me, I prefer to go all out, get the best specs, and then keep it for a long time. My computer right now is about five years old, which for a computer is pretty darn old. Plus, I also changed my laptop after seven long years and bought Acer Predator Helios 300.
Over time, I upgrade a little bit of the components inside, like the GPU or RAM, when better stuff comes out. So I would probably prefer to get something that’s more future proof that I can upgrade for longer.
If you build a DDR4 computer: Well, DDR4 is closer to getting as good as it’s going to get. At this point, not much will be able to be upgraded down the line, whereas DDR5 it’s going to improve.
The third big thing you need to consider is how badly you want or need to upgrade your computer right now. If you have been planning and want to build a computer right now, you’re probably fine doing just that.
DDR5 is at least a year out from writing this article, and it’s going to be even longer before it comes down in price and reaches its full potential. On the other hand, if you’re someone who’s been thinking about upgrading your PC in the next year, then it would be better for you just to wait.
You can use all the extra time to potentially budget and save up a bunch more money and then buy a bigger and better one anyway when you are ready to get it. I am probably just going to wait for DDR5.
I did say that my computer is getting pretty old, but I recently bought a gaming laptop, which makes up for the heavy tasks.
The difference between DDR4 and DDR5 will not be noticeable for most people, even if you’re a gamer. Most of the time, the bottleneck is going to be in the CPU and the GPU. The RAM is probably not going to be the bottleneck on your computer, so it’s not going to make a difference.
It’s probably better for you to just get a good GPU, good CPU and decent RAM. The cheaper DDR4 RAM will give you more money to put on other components.
Hopefully, with all that information, you can now make a better decision on whether you want to wait for a new computer with DDR5 or get one now with DDR4.