When we talk about the performance of a CPU, the clock speed and the core count are the main things to come to mind. This isn’t smart as these factors are misleading, and don’t account for IPC.
IPC is often neglected as it isn’t a popular metric that is used to show performance, but this doesn’t mean it isn’t important. In fact, the IPC is probably more important than the clock speed for very specific reasons.
IPC stands for Instructions per clock, and it defines how much work your processor can do per clock cycle. So, IPC is pretty crucial when you want to understand how fast your CPU is in terms of single-core performance.
For More On Single-Core Performance: Check Out What Is Single Core Performance?
How Does IPC Affect Performance (Benchmarks & Specs)
So, the IPC defines how much work your processor can do per clock cycle, imagine two processors with the same clock speed (5GHz).
If one of the processors has a 10% IPC improvement, then it will outperform the other processor despite the clock speeds being identical.
You’re probably wondering how we can determine the IPC of a CPU, well it’s not easy as it’s not a metric CPU manufacturers typically show; nonetheless you can still measure it.
You typically find the IPC by running benchmarks, typically single core performance benchmarks, and find which processors are performing exceptionally well despite having similar clock speeds.
IPC improvements are a product of the architecture of a CPU, so a better CPU architecture will increase the single-core performance without changing the clock speed.
If we compare the I9 12900K running on the Alder lake architecture to the I9 10900K running on the Comet Lake architecture, we find that the I9 12900K is faster even though the I9 10900K has a 100MHz clock advantage.
So an easier and a pretty obvious way of finding out whether a CPU has a higher IPC is to check the CPU generation. The 12th generation Intel processors outperform the 10th generation Intel processors.
As you can see from the table above, the previous generation is always outperformed by the latest generation despite the clock speeds being the same, or even superior.
This is why it’s recommended to never look at clock speeds when buying a CPU as it’s extremely misleading, this could cause you to purchase an older CPU with high clock speeds.
Intel Vs Ryzen For IPC
With IPC, you are able to compare completely different architectures to find out what architecture is better single-core wise.
This really does work if you know what to look for, and you can end up purchasing a CPU with lower clock speeds, but superior single-core performance.
An example of an architecture being superior and providing better results in terms of single core performance is the Ryzen 5000 chips with the Intel 10th gen chips.
The Ryzen 5000 chips were able to outperform their Intel competitors in single-core tasks, and this is pretty rare as Intel is known for being the best CPUs single-core wise.
The Ryzen 5 5600X clocked at 4.60GHz boost was able to outperform the I5 10600K clocked at 4.80GHz boost in most games.
But as always, check out single-core benchmarks to get a better idea on a CPUs IPC compared to a processor of a different generation.
Nowadays, Ryzen is known for being more multi-core friendly which makes Ryzen a better choice if you’re looking to stream or video edit.
And Intel is better for raw performance offering huge clock speeds and plenty of cores, so Intel is more of a premium option.
How Does Clock Speed Affect Performance?
Despite the CPU clock speed being misleading, it’s actually pretty important, and you shouldn’t forget it especially when building a gaming PC.
The clock speed only makes sense when you’re comparing CPUs from the same architecture, so that means 12th gen processors with 12th gen processors.
The same applies with Ryzen processors, so 7000th gen Ryzen chips with other 7000th gen Ryzen chips.
This pretty much removes any effect the IPC has on the processor, this allows you to make better choices when picking a CPU for single-core performance.
So, the clock speed is pretty important overall, but especially important for gamers. This is because most games are coded in such a way that they benefit from the clock speed mostly; there are some exceptions.
So, comparing the I9 12900K to the I5 12600K, the I9 12900K will win because it can reach a boost clock speed of 5.20GHz, whereas the I5 12600K can only reach 4.90GHz.
You will notice higher frame rates in games as the CPU acts as a bottleneck to the GPU. But an easier way to visualise this is to look at the numbers.
| Processor | Clock Speed | PassMark Single-Thread |
|---|---|---|
| I9 12900K | 5.20GHz(boost) | 4,375 |
| I7 12700K | 5.00GHz(boost) | 3,974 |
| I5 12600K | 4.90GHz(boost) | 3,973 |
| Ryzen 9 5900X | 4.80GHz(boost) | 3,469 |
| Ryzen 7 5800X | 4.70GHz(boost) | 3,452 |
| Ryzen 5 5600X | 4.60GHz(boost) | 3,359 |
As you can see from the table above, the processors of the same generation but higher clock speeds produce higher single-core results. You can expect this to reflect the same way in video games.
What About Overclocking?
Overclocking is when you push your CPU’s clock speed past its stock values, so in a sense, the clock speed is better than IPC since you can modify it depending on the processor.
But with Intel, if the CPU has a “K” suffix, this means the CPU is unlocked and ready to overclock, and AMD CPUs are mostly overclockable.
You usually overclock by modifying the clock speed modifier within the BIOS, and you will need to have a motherboard that allows for overclocking; this mostly depends on the chipset.
Overclocking can be quite risky if you don’t know what you’re doing, and you don’t have sufficient cooling. You can end up ruining a chip messing with the voltages too much.
But yes, the clock speed of your processor can be modified without purchasing a new CPU whereas the IPC is unchangeable and completely dependent on the CPU’s architecture.
Boost clock speeds are a form of automatic overclocking, and requires no user input. This is a great way to get extra performance out of your processor in CPU intensive situations.
For boost clock speeds to activate, you need to meet certain TDP and thermal conditions, so you will need a decent power supply and CPU cooler.
It’s worth noting that boost clock speeds don’t last forever, for example, your CPU won’t boost if you’re just browsing the web as that’s a massive waste of resources.
Conclusion
In conclusion, the clock speed is pretty irrelevant if you’re comparing processors of two completely different architectures and generations due to IPC differences.
Once you compare CPUs of similar generations, for example the Ryzen 5 5600x with the Ryzen 7 5800x, comparing the clock speeds will make more sense, and the IPC becomes irrelevant.
