GPU Memory Clock vs Core Clock: What's the Difference?

Lindsay Hayes

Your graphics card has a graphics processing unit (GPU) and RAM. Just like a CPU, the GPU has a core clock speed that indicates how many calculations it can do per second. Just like regular RAM, the video RAM also has a memory clock speed that tells you how quickly the GPU can access the data stored on the memory. One determines how fast data can be processed, and the other, how fast it can be accessed.

If you're planning to buy a graphics card, you absolutely need to understand the specs to make the best choice between multiple models. My cousin complained that he wanted to get a new graphics card for his desktop but he couldn't tell the difference between the two clock speeds. Fortunately, I was there to set him straight.

So, if you want to know what makes GPU memory clock speed and core clock speed different from one another, this article will show you. Let's get into it.


What is the Difference Between the Memory Clock and the Core Clock of a GPU?

Your graphics card works the way it does through a combination of components. Two of the most important of these are the actual GPU chip and your video RAM (VRAM).

Each of these has its own unique set of specifications, but clock speeds are one that they share in common. There's a GPU memory clock speed and a GPU core clock speed.

Let's get into how these are different from each other. The first step to doing that is to talk about each one in detail.

Graphics Card on a Black Table

What is GPU Memory Clock Speed?

Your graphics card has video RAM which is memory specifically dedicated to your graphics card. It can't be used by the rest of your computer in the same way that regular RAM is.

It is very similar to regular computer memory. When you load an application that is going to use the GPU, assets and other data are stored in the memory so that they can be loaded from there, quicker than they could be loaded straight off of your hard drive.

So, your GPU memory can store data and then send it for processing faster than your hard drive can. But how do you measure how fast that is exactly?

That's where your GPU memory clock speed comes in. This is usually measured in MHz and directly represents how fast your GPU can access data stored on the VRAM.

For instance, the Nvidia GeForce 1650 has a memory clock speed of 8000 MHz.

What is GPU Core Clock Speed?

Now, your GPU core clock speed is an important factor to consider when trying to assess what your graphics card is capable of.

Although "GPU" is frequently used interchangeably with "graphics card", the GPU is the actual chip on the board of your GPU that is responsible for all the graphical calculations and processing.

Similar to a CPU, your GPU has a core clock speed which refers to how many calculations it can do in a single second. This is typically measured in MHz or GHz.

The faster your GPU's core clock speed, the more graphical calculations it can make at a time.

The Nvidia GeForce 1650 has a GPU core clock speed of 1485 MHz.

What is GPU Boost Clock Speed?

Once again, just like a CPU, modern GPUs have the ability to push up to a higher core clock speed when it is needed during operation. The limit to how high the core clock speed can go is what is referred to as the boost clock speed.

An example is the Nvidia GeForce 1650 which has a base clock speed of 1485 MHz but if there's extra power needed when gaming or working, it can push to a higher core clock speed of at most 1665 MHz.

What is the Difference Between Memory Clock and Core Clock Speeds?

While your GPU and your GPU memory work in close connection to each other, and while their clock speeds might use the same unit, you should understand how different they are from each other now.

Your GPU does the heavy lifting and your GPU clock speed is a good indication of how quickly it can do that work.

Your VRAM serves as a place to store information that is about to be processed or was just processed. When your GPU needs to access any of this information, the GPU memory clock speed determines how fast it can be retrieved from there.

To summarize, one speed is all about the actual processing and the other is about the speed of access.

Gaming GPU MSI Nvidia Geforce GTX 780 Twin Frozr

Which Should I Focus on More When Buying a Graphics Card?

Now that you fully understand your GPU memory clock speed and core clock speed specifications, you might be wondering which of the two is the most important factor when trying to assess a GPU's performance.

Let's talk about that a little then.

Between a higher memory clock speed and a higher core clock speed, there are unique instances where either one should be prioritized.

A higher memory clock speed will improve your GPU's performance when it comes to tasks where a large amount of data is stored in your VRAM. For instance, if you're working with several gigabytes of 3D models or attempting to play 4K or 8K video footage.

However, if you do things that require the graphics card to do a lot of calculations quickly, then a higher core clock speed is what you should be looking for. This can benefit you in cases where you're playing intensive games or editing and rendering video.

What Does GPU Overclocking Do?

Just like you can overclock a computer's central processing unit to squeeze more juice out of it, the same can be done to a graphics card to increase the GPU's performance.

GPU overclocking gives you the opportunity to push up your GPU memory clock speed and core clock speed to get more performance out of your system — perfect for a gaming PC.

However, this can only be done if both your graphics card and motherboard support overclocking.

Just keep in mind that while overclocking can improve your GPU's performance, you will need to make sure your PC is built to handle the increased power consumption and higher GPU temperatures that this can cause. This means you may need a power supply unit with a high enough capacity as well as a capable cooling solution.

Also, keep in mind that overclocking can damage your GPU, so only do it at your own risk. This will be a time-consuming process too, especially if you want to do it effectively.

Nvidia RTX 2080 Graphics Card

Let me give you a basic run-through of how to overclock and increase your GPU's performance if you're ready to jump into that.

  1. The first thing that you need to do is to figure out your GPU's performance before you move to overclock it. This will give you a baseline value and let you know if your changes actually help to improve performance. You can do this using 3DMark Time Spy or any other GPU benchmark test. Once you download, install, and run it. However, while running it, you want to keep an eye on your GPU's temperature and power consumption.
  2. Once the benchmark is done, you should get a score. Keep it in mind, because all your overclocking efforts will be compared to it.
  3. If your GPU temperature was going over 85°C during the benchmark, you'll want to increase your fan speed or get a better cooling solution. With overclocking your GPU, this temperature will get way higher, so you will have to have better cooling to avoid overheating.
  4. Now, you'll have to do a little research. It is very important to find what the safest maximum voltage is for the card you're trying to overclock. Going too high can actually damage your GPU, and that's the last thing you want to have happen to an expensive card. However, some cards may limit how high you can push the voltage and some will simply not have the option, which can be helpful.
  5. Now, it's time to actually download the overclocking software. There are different options, but MSI Afterburner is the most popular choice, so we'll use that. Download, install, and launch it.
  6. Now, as long as you've got a GPU and a motherboard that support overclocking, you'll be able to use Afterburner to attempt to improve your graphics card's performance.
  7. The first thing to do is to crank the "Power Limit" slider under "Fan" to the maximum.
  8. Next, move to the "Clock" section and push up "Core Clock" by a little. This will increase your GPU's core clock speed, but make sure not to increase it by more than 5% at a time.
  9. Once done, save your changes.
  10. Now, go straight back to the benchmark and run it again. You can take a look at the score, but for now, the goal is to make sure that your GPU's core clock speed is stable and doesn't cause glitches or crashes. The longer you run the benchmark without an issue, the more certain you can be of a stable overclock. 30 minutes is a good target.
  11. If your new core clock speed is stable, you can go back and increase the GPU's core clock speed by a little more. Basically, run through steps 8 to 10 again.
  12. Now, if you start seeing glitches, you can either go back to the last stable core clock speed (especially if you can't increase the voltage on your GPU) or you can try to improve stability. You can improve stability using the "Core Voltage" slider.
  13. To be safe, you should increase voltage in small increments of 25mV at a time. Save your change and then run the benchmark again. Keep in mind that with each increase in voltage, your GPU will drink more power and run hotter. Watch your GPU temps to make sure they don't go way over 85°C.
  14. If you still face glitches, go back and increase the voltage a little more and run the benchmark again, up until you get a stable overclock with no glitches.
  15. At this point, you've increased core clock speed and voltage. You've been able to improve performance, but you can actually go back to step 8 and increase your core clock again. However, after bouncing between raising voltage and GPU clock speed, you will eventually get to a point where you can't achieve stability anymore. If that's the case, just settle on the highest stable values you were able to reach.
  16. Once you've done that, you can run through steps 8 to 10 again, except using the "Memory Clock" option in MSI Afterburner.

It takes a lot of steps, but overclocking can be worth the performance increase you can squeeze out of your graphics processor.

Inside of a Gaming PC

Once you're done, you can compare your final benchmarks with the initial ones to assess the performance increase. It's also a good idea to test real-world performance, whether it is while playing a game or video rendering.

Final Words

There's a big difference between memory clock speed and core clock speed. Memory clock speed refers to how quickly data can be accessed from video RAM and passed to the GPU. Meanwhile, core clock speed refers to how fast your graphics card can do calculations and handle instructions thrown at it. Both of these are important in judging the overall performance of a graphics card.

Using programs like MSI Afterburner, you have the option to increase the memory clock speed and core clock speed of your GPU. This is a great option for people who want better gaming performance and have compatible hardware. I recommend finding stability while increasing either of the clock speeds to its fullest before touching the other.

Was this article able to tell you everything you need to know about memory clock speed and core clock speed? If so, take a look at our other articles to learn more cool things.

Lindsay Hayes

Hi, I’m Lindsay, a techie from Kansas City. That’s right; I’m a born and bred Midwesterner. I learned to take electronics apart at my dad’s GameStop way back when, and I haven’t stopped since. I spend most of my time checking out new gadgets.
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