When it comes to the performance of your processors, usually you’ll think about only the clock speed and the core count. However, IPC or Instructions Per Clock is another metric that determines how fast your processor is. All CPUs have a set amount of IPC, but it seems like this specification is often hidden from us, but we can notice their effects
In this post, we’re going to go over exactly what is IPC and how it works, what is the clock speed, and compare the two biggest manufacturers, Intel and AMD. By the end of this post, you should have a general idea of how the IPC influences your processor’s performance.
Answer: Without knowing the IPC of your processor, you may be fooled into purchasing a very old processor with a high clock speed thinking you’ve found a bargain. Over the years, processors have made massive IPC improvements but the clock speeds have mostly stayed the same, this is where the additional performance is coming from, newer processors are basically more efficient.
What Is IPC?
IPC(Instructions Per Cycle/Clock) refers to how many instructions a core can execute per clock cycle, so the more instructions your processor can do per clock cycle, the faster the processor will be. Compared to two processors clocked at 5GHz, the processor with a higher IPC will be the fastest out of the two. This is why older processors will mostly lose to newer processors clocked at the same speed.
The IPC of the processor is a product of its architecture, a processor with a superior architecture will ultimately have the highest IPC, but this is a heavily simplified explanation. Architecture improvements are a result of implementing small differences and techniques to make a more efficient CPU, CPU companies such as Intel and AMD will use the tricks to improve upon their CPUs performance whilst keeping the clock speeds the same.
Instructions flow through a processor in stages, and the goal is to improve the effectiveness of each stage consequently improving the architecture. Methods such as implementing a more effective pipeline will increase IPC, this is due to improving upon how instructions flow through a CPU. The pipeline usually consists of a few stages, Fetch, Decode, and Execute, instead of waiting for a single instruction to go through the pipeline, you can have multiple in different stages in the pipeline. You can have one instruction in the fetch stage, and another in the decoding stage.
What Is Clock Speed?
Clock speed refers to how many clock cycles are achieved per second, a 4GHz CPU will cycle 4 billion times a second. When purchasing a processor, it’s easy to say that the processor with the highest clock speed is the superior processor, this is because it’s marketed to be this way. Processors with a 5GHz clock speed that cycles 5 billion times a second sounds more attractive than knowing the IPC. But as we know already, the clock speed doesn’t tell the full story when it comes to performance.
During each clock speed, instructions are being executed which are usually arithmetic instructions, so it’s a really large amount of instructions being calculated per second. You can see why clock speed shouldn’t be the determining factor when you purchase a CPU because it really only tells half the story. The reason why clock speed is arguably the most important aspect of the CPU is that back in the day, processors only had a single core, therefore the main determining factor to the speed was the clock speed.
Nowadays, you have core count and clock speeds which are the main determining factors of speed. If you have a 10 core processor clocked at 4GHz, then all 10 of those cores will run at 4GHz individually, clock speed isn’t divided between the cores. There are also methods of increasing the clock speed, this is called overclocking and it can be done through the BIOS usually. So the clock speed is more attractive, can be modified by the user depending on the chip, and directly correlates to how fast the CPU runs.
Also Read: What Is A Good CPU Clock Speed?
Ryzen Vs Intel – What Processors Are Faster?
Usually, Intel is winning when it comes to the IPC race, but with the Ryzen 5000 series, the IPC improvements have been substantial, even surpassing the Intel 10th generation CPUs. The Ryzen 5000 series has a 15% IPC increase compared to Intels 10th gen or Comet lake processors. But with the release of the Intel 12th series, the IPC increases have been massive, and Intel has taken back its crown for single-core performance.
This is the reason why Intel is the popular choice with gamers, and Ryzen is the popular choice with budget seekers and users looking for massive multicore processors. Intel usually offers higher IPC and higher clock speeds which is all you need for single-core performance. With single-core performance, it allows gamers to reach higher frame rates due to the majority of games being single-core optimized.
Ryzen on the other hand usually offers more cores which means Ryzen is more optimized for multithreaded applications. The Ryzen Threadripper CPUs can come with up to 32 Cores which can be used for professional multithreaded tasks such as video editing, x264 encoding, and streaming. So Ryzen is more of a multi-core option whereas Intel is more of a single-core option.
Conclusion
The verdict is we will say that IPC is important because it directly shows how efficient the CPUs architecture is, without improving the architecture, we’d recommend more on clock speed which hasn’t really been improving over the years. IPC is just another way of improving performance but isn’t as popular as the clock speed or core count.
Only focusing on clock speed is a good way to fool yourself into purchasing an old-generation processor with a high clock speed. A new generation processor clocked at 4GHz will probably be faster than an old generation processor clocked at 5GHz, this is due to the IPC increases being achieved over the years.
Typically, Ryzen processors have more cores, and more budget options and Intel is more of a premium option for users looking for high clock speeds, high IPC, and usually high core counts, but it usually comes at a premium price. This is why Intel processors are best for gaming machines.
