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Does CPU Limit RAM Speed In Modern Computers In 2022?

Does CPU limit RAM? Yes, the CPU can limit RAM because CPU architecture affects the number of address bus bits.

Integrated circuitry places physical limits on the pins available for the memory bus. This is known as a CPU addressing limit. 

Other factors can also limit RAM. Older operating systems are 32-bit, and all have a fixed RAM limit of 4GB. This is because the physical addresses are 32-bit, and every byte requires one.

So 2^32 bytes is equal to 4GB. Economic concerns also influence RAM limits, which is why manufacturers only install as much RAM as necessary. 

In this article, we’ll dive deeper into the relationship between the CPU and RAM limits. We’ve divided it into a set of popular topics and answered some frequently asked questions at the end.


What Does RAM Speed Do?

RAM speed has several elements. The primary ones are the RAM frequency and the CAS latency. The frequency is in megahertz, which derive from cycles.

One read and one write form a cycle. The more cycles your RAM can do in 1 second, the faster it is. As an example, 2400Mhz is 2.4 billion cycles per second.

CAS latency measures the delay between receiving an instruction and executing it. It features 4 timings measuring different RAM operations.

We’ve observed that RAM with a low frequency but high latency can outperform RAM with a higher frequency.

How Does RAM Speed Affect Performance? 

We’ve seen that the faster the RAM speed, the quicker a computer processes operations. Faster RAM transfers data to other components at higher speeds. This can make your computer operate smoother. 

Computer ram memory on white background

If your CPU (check out the best ones for programming here) and RAM are both fast, this will ensure better performance. If one is slower, the extra speed of the other component will be less effective. And tasks such as rendering will suffer.

To address this, we recommend upgrading the RAM. It will be easier to upgrade unless you’re already at maximum capacity.

Does CPU Limit RAM?

The CPU in your computer will limit RAM speed because it has a maximum RAM frequency limit. If the CPU has a limit (check out some budget CPUs under $200 here) of 1600MHz and your memory operates at 2400MHz, the extra speed will not be used.

The memory controller built into modern CPUs enforces this limit. But I’ve found that you can enable XMP profiles for some systems to overclock the RAM.

If you do this, be careful not to go beyond hardware limitations for the CPU or motherboard.

Does CPU Limit Max RAM Speed?

Despite XMP profiles, there are hardware limits for RAM speed based on the CPU. Older CPUs will have lower RAM limits, and newer CPUs will have higher RAM limits. 

If you buy faster RAM than your CPU can support, the extra RAM speed will remain unused. This is why I think it’s better to buy RAM sticks that matches your CPU capacity.

This is especially relevant if you’re not comfortable with overclocking.

Does The Capacity Of RAM Depend On The Processor?

If you’re wondering does CPU limit RAM, then you might also wonder if it limits the capacity as well as the frequency. Depending on how old it is, it can, but other factors are more important. 

Does The Capacity Of RAM Depend On The Processor

We’ve noticed that if a computer runs out of RAM, it has to read and write from the hard disk. This vastly reduces the smoothness and speed of operations on the system.

The effect of this outweighs a slower CPU.

Does CPU Frequency Affect RAM Speed? 

The frequency of the CPU and the speed of the RAM are two different factors. They do not influence each other directly.

But there is an indirect relationship. If you have a very old CPU, the motherboard will likely be of similar age. This means the maximum supported RAM speeds will be lower.

Does More RAM Affect The CPU?

If installing extra RAM, ensure you don’t exceed the CPU, operating system or motherboard limits. The CPU won’t affect the amount of RAM you can put into your system.

But it can impact the frequency limit, as we’ve mentioned. 

As for whether the RAM itself affects the CPU, it’s unlikely unless there isn’t enough RAM available. This won’t be an issue if you’re adding RAM.

Is The RAM Or The Processor More Important? 

We believe neither of these components is more important than the other. If your computer lacks RAM, it won’t function. The same is true if it lacks a CPU.

Is The RAM Or The Processor More Important 

Both of these components complement each other and additional components in your computer. This includes the hard drive and motherboard.


Does The Motherboard Limit RAM?

Yes, it can. When you buy a new computer, you should be able to find a specification chart. It will include information about RAM slots, plus their maximum capacities and frequencies.
New computers will have a preinstalled CPU, RAM, and other components. CPUs are difficult to replace, but any new CPU will still be subject to the motherboard RAM limit. This is why we recommend prioritizing the motherboard RAM limit.

Does RAM Speed Really Matter?

The speed of your RAM determines the speed at which your computer completes calculations. This means it affects how productive you can be in the time that you have. So I think it does matter because it impacts how much time you’ll need to spend on the computer to complete tasks. For more information, we’ve found a good video discussing RAM speed.

What Happens If I Use RAM Faster Than The CPU?

If you insert faster RAM than your CPU supports, it will operate within the CPU limit. This means it’s worth selecting RAM for an upgrade only once you know this information. If you’re buying a new computer, it will come with RAM within the CPU’s frequency limit.

Can My Computer Use Newer And Faster Memory?

If you’re considering an upgrade for your RAM, consider a few points upfront. First, you should factor in the CPU, operating system and motherboard RAM limits we’ve discussed. Then, you should ensure the memory sticks share module types and frequencies. This way, you’ll minimize complications when upgrading the memory.