Closeup of a microprocessor with clearly visible silicon core and cache chip.
rawcapPhoto/Shutterstock.com
The amount of cache you need depends on what you plan to do with your computer. Use benchmarks to find a CPU with the right mix of cache, cores, and clocks to run the applications you need.

Buying a new CPU is already hard enough when you only have to worry about cores and clock speed. So what are these “cache memory” specifications all about, and how much of this stuff should you get in your next CPU?

What Is CPU Cache Memory?

CPU cache is small, fast memory that stores frequently-used data and instructions. This allows the CPU to access this information quickly without waiting for (relatively) slow RAM.

CPU cache memory is divided into different levels, with each level providing faster access to data and instructions. The smallest and fastest level of cache is called L1 cache, followed by L2 cache and L3 cache. L1 cache is typically built into the CPU itself, while L2 and L3 cache are usually located elsewhere nearby.

Why Does CPU Cache Memory Matter?

CPU cache memory matters because it directly affects the performance of a CPU. The more cache memory a CPU has, the less time it spends waiting for data, leading to lost performance. However, cache memory is also a limited resource, and adding more cache memory to a CPU can also significantly increase both its power consumption and its cost.

Different Tasks Require Different Amounts of Cache Memory

The amount of cache memory that different CPU tasks require can vary, and it’s not really possible to offer specific cache sizes to aim for. This is especially true when moving from one generation of CPU to the next, since newer CPUs may have faster cache memory allowing them to do more with less. In general, tasks that require frequent access to large amounts of data, such as gaming, video editing, and scientific simulations, can benefit from having more cache memory.

On the other hand, tasks that don’t need frequent access to large amounts of data, such as basic web browsing and word processing, may not benefit as much from having more cache memory. Consider what you’ll use your computer for before making a purchase decision so you don’t overbuy.

How to Choose the Right Cache Size

Once you’ve determined which applications you want to run and you know cache size will affect performance in those applications, how can you strike the right balance between core count, processor speed, and cache size?

The most practical way is to look up benchmark results for the CPUs you’re considering in applications or games you’ll actually run on your new CPU. CPUBenchmark.net is one place you can get that information. Use your CPU budget as the guiding factor and see whether a CPU with more cache for that budget has a bigger impact on performance than one with faster clocks or more cores.

For example, the AMD 5800X3D offers fantastic gaming performance thanks to its massive cache allocation, but it falls short in applications such as video editing compared to similarly-priced CPUs with more cores.

AMD Ryzen 7 5800X3D

The king of gaming performanc CPUs got its crown thanks to heaps of advanced 3D-stacked cache memory, although it you also want to do tasks that benefit from more than 8 cores, it may not be as fast as the competition.

You might also consider how sensitive your intended applications are to RAM bandwidth and speed. In some cases you may benefit more from diverting some of your budget to faster RAM than to more cache on your CPU. The most important rule is not to get bogged down in how many megabytes or levels of cache a CPU has. The only thing that matters is real-world performance!

Profile Photo for Sydney Butler Sydney Butler
Sydney Butler has over 20 years of experience as a freelance PC technician and system builder. He's worked for more than a decade in user education and spends his time explaining technology to professional, educational, and mainstream audiences. His interests include VR, PC, Mac, gaming, 3D printing, consumer electronics, the web, and privacy. He holds a Master of Arts degree in Research Psychology with a focus on Cyberpsychology in particular.
Read Full Bio »