Readers like you help support MUO. When you make a purchase using links on our site, we may earn an affiliate commission. Read More.
The processor is the brain of a computer, but understanding the difference between processors requires a lot of brainpower of your own. Unfortunately, Intel has a confusing naming scheme, and the question we get asked most often is: What's the difference between an i3, i5, or i7 processor? Which CPU should I buy?
It's time to demystify that. Read on to learn about the difference between an Intel Core i5 and a Core i7, if a Core i3 is any good, and whether you should buy an Intel Core i9.
The Differences Between Core i7, Core i5, and Core i3
An Intel Core i7 is better than a Core i5, which in turn is better than a Core i3. The trouble is knowing what to expect within each tier. Things go a little deeper.
First, Core i7 does not mean a seven-core processor! These are just names to indicate relative performance.
Older Intel Core i3 series had only dual-core processors, but more recent generations have a mixture of dual- and quad-core CPUs.
It is a similar story for older Intel Core i5 CPUs. Older generations of Intel Core i5 processors had a mixture of dual- and quad-core processors, but the later generations typically feature a quad- or even hexa-core (six) configuration, along with faster overclock speeds than the Core i3. The latest i5 generation includes 10-core CPUs.
The latest Intel Core i7 CPU generations include quad-core, hexa-core, and octa-core, and 12-core configurations. Again, the Intel Core i7 CPUs outperform their Core i5 counterparts and are much faster than the entry-level Core i3 CPUs.
Quad-cores are usually better than dual-cores and hexa-cores better than quad-cores, and so on, but it isn't always accurate depending on the CPU generation—more on these differences in a moment.
Intel releases "families" of chipsets, called generations. At the time of writing, Intel has launched its 12th-generation CPUs, named Alder Lake. Each family, in turn, has its own line of Core i3, Core i5, and Core i7 series of processors. The latest CPU generations have another tier above Core i7, the Intel Core i9.
The Intel Core i9 series is Intel's extreme performance line. Most Core i9 CPUs are now 16-core beasts (doubling the octa-configuration of the previous generation) and come with a very high clock speed, enabling them to perform to a very high standard for prolonged periods. They may also come with a larger CPU memory cache than their counterparts, enabling faster overall performance.
Intel's 12th Gen CPUs added another consideration for would-be users: Hybrid Cores.
However, with the 12th generation Intel Core, we now get different Performance and Efficiency cores.What this does is that the processor uses Performance Cores (P-Cores) for priority apps running in the foreground while the Efficiency Cores (E-Cores) are used for background tasks. For example, when you're gaming, the P-Cores will handle your game while the E-Cores will work on background tasks, like your streaming app.Similarly, P-Cores are best used for single-thread and lightly-threaded tasks, like games and productivity apps, while it designates highly-threaded apps to the E-Cores. This ensures that your computer makes efficient use of the available processor power.
Now while this doesn't make a huge amount of difference when you're choosing between an i3, i5, or i7 CPU, each of these CPU types comes with a different Hybrid Core configuration.
How to Tell Which Intel CPU Generation Is Which?
You can spot which generation a processor belongs to by the first digits in its four or five-digit model name. For example, the Intel Core i7-11700K belongs to the 11th generation.
For a long time, a useful rule of thumb for Intel CPU model names was that the other three digits were Intel's assessment of how the processor compares to others in its own line. For example, an Intel Core i3-8145U is superior to the Core i3-8109U because 145 is higher than 109.
That rule is still in place, but it isn't always as easy to follow as it once was as there are several other product line modifiers you can find in the model number. However, "A higher SKU within otherwise-identical processor brands and generations will generally have more features," as per Intel's naming convention guide.
Furthermore, this change is another reason why comparing CPUs across generations using their model number alone is advisable, as Intel tweaks things.
What Intel's Model Letter Suffixes Mean: U vs. HQ vs. H vs. K
As you can see, the model number will typically be followed by one or a combination of the following letters: U, Y, T, Q, H, G, and K. Here's what they mean:
- U: Mobile power efficient. The U rating is only for mobile processors. These draw less power and are better for battery life.
- Y: Extremely Low Power. Processors designed for devices with extremely low power requirements, such as Internet of Things devices or other embedded hardware.
- T: Power Optimized for desktop processors.
- H: High-Performance Mobile. These CPUs are high-performance models optimized for mobile hardware.
- HK: High-Performance Mobile, but also has an unlocked CPU which allows for overclocking.
- HQ: High-Performance Mobile. Optimized for mobile hardware, with a quad-core processor.
- G: Includes Discrete Graphics. Typically found on laptops, this means there is a dedicated GPU with the processor.
- G1-G7: The level of integrated graphics performance you can expect.
- K: Unlocked. This means you can overclock the processor above its rating.
- KF: Unlocked, no integrated graphics. These high-performance CPUs can be overclocked, but they do not come with onboard graphics.
- S: Special Edition processors, usually featuring very high-performance hardware.
Understanding these letters and the numbering system above will help you know what a processor offers just by looking at the model number without needing to read the actual specifications.
Intel Core i7 vs. i5 vs. i3: Hyper-Threading
The physical cores largely determine the speed of a processor. But with how modern CPUs work, you can get a boost in speed with virtual cores, activated through hyper-threading.
In layman's terms, hyper-threading allows a single physical core to act as two virtual cores, thus performing multiple tasks simultaneously without activating the second physical core (which would require more power from the system).
If both processors are active and using hyper-threading, those four virtual cores will compute faster. However, do note that physical cores are faster than virtual cores. A quad-core CPU will perform much better than a dual-core CPU with hyper-threading!
The difficulty is that there is no blanket approach from Intel regarding hyper-threading on its CPUs. For a long time, only Intel i7 CPUs featured hyper-threading, with a few Intel Core i3 CPUs but no Intel Core i5 CPUs. That situation changed with Intel's 10th Gen CPUs, with some Core i5 processors launching with hyper-threading, but prior to this, Intel disabled hyper-threading on some of its Intel Core i7 9th Gen CPUs in response to security risks.
In short, you'll have to check the individual CPU for its hyper-threading potential, as Intel appears to chop and change with each processor generation.
One thing is for sure: the fastest Core i9 series does support hyper-threading.
Intel Core i7 vs. i5 vs. i3: Turbo Boost
All of the latest Intel Core processors now support Turbo Boost frequencies. Previously, Intel Core i3 owners were left out in the dark, forced to suffer with their regular CPU speeds. However, as of the Intel Core i3-8130U, the CPU manufacturer began adding higher frequency modes to the entry-level CPU series.
Of course, Core i5, Core i7, and Core i9 CPUs all feature Turbo Boost, too.
Turbo Boost is Intel's proprietary technology to intelligently increase a processor's clock speed if the application demands it. So, for example, if you are playing a game and your system requires some extra horsepower, Turbo Boost will kick in to compensate.
Turbo Boost is useful for those who run resource-intensive software like video editors or video games, but it doesn't have much of an effect if you're just browsing the web and using Microsoft Office.
Intel Core i7 vs. i5 vs. i3: Cache Size
Apart from Hyper-Threading and Turbo Boost, the one other major difference in the Core lineup is Cache Size. The cache is the processor's own memory and acts like its private RAM. Upgrading to a newer CPU with a larger memory cache is one of the upgrades that will benefit your PC the most.
Just like with RAM, more cache size is better. So if the processor is performing one task repeatedly, it will keep that task in its cache. If a processor can store more tasks in its private memory, it can do them faster if they come up again.
The latest generations of Core i3 CPUs typically come with between 4-12MB of Intel Smart Cache memory. The Core i5 series has between 6MB and 20MB of Intel Smart Cache memory, and the Core i7 series has between 12MB and 25MB of cache. The Intel Core i9 series tops the list, with each CPU coming with between 16MB and 30MB Intel Smart Cache memory.
Intel Graphics: Xe, HD, UHD, Iris, Iris Pro, or Plus
Ever since graphics were integrated into the processor chip, integrated graphics have become an important decision point in buying CPUs. But as with everything else, Intel has made the system a little confusing.
Intel Graphics Technology is the umbrella term covering all Intel integrated graphics. Within that, there are different generations of Intel integrated graphics technology, confusingly referred to by both series names and generational names. Still following?
- Intel HD Graphics was first introduced in 2010 as the first series under this umbrella but is actually Gen5 (5th generation) in terms of development.
- Intel Iris Graphics and Intel Iris Pro Graphics were introduced in 2013 and are Gen7 integrated graphics units. The Iris Pro Graphics units were pretty big news at the time as they integrated DRAM into the module, giving the graphics performance an extra boost.
- Intel UHD Graphics launched with Intel's 10th Generation mobile CPUs and is only available on certain laptop model processors.
- Intel Xe (known as Gen12 integrated graphic) was a massive step forwards for integrated graphics, using a new architecture to deliver much higher integrated graphics performance than previous generations. Adding to the confusion, some of the Intel UHD Graphics models use Intel Xe architecture, further muddying the water.
The best advice for how to interpret these? Just don't. Instead, rely on Intel's naming system. If the processor's model ends with HK, you know it's a model with high graphics performance and an unlocked CPU. If it ends with a G, that means there is a dedicated GPU, not one of Intel's chips.
Choosing Between Intel Cores i3 vs. i5 vs. i7 vs. i9
Generally speaking, here's who each processor type is best for:
- Intel Core i3: Basic users. Economic choice. Good for browsing the web, using Microsoft Office, making video calls, and social networking. Not for gamers or professionals.
- Intel Core i5: Intermediate users. Those who want a balance between performance and price. Good for gaming if you buy a G processor or a Q processor with a dedicated graphics processor.
- Intel Core i7: Power users. You multi-task with several windows open at the same time, you run apps that require a lot of horsepower, and you hate waiting for anything to load.
- Intel Core i9: The extreme performance tier is marketed for those that demand the best and fastest performance in every area of their machine.
How Will You Choose Between Intel Core CPUs?
This article provides a basic guide for anyone looking to buy a new Intel processor but is confused between Core i3, i5, and i7. But even after understanding all this, when it's time to decide, you might need to choose between two processors from different generations because they're priced the same.
When you're comparing, my best tip is to head to CPU Boss, where you can compare both processors and get a detailed analysis, as well as ratings. If you don't understand the jargon, just go with the rating and the basic advice. Even if you understand CPU jargon, CPU Boss has all the details you'll need.
Most People Don't Need Intel Core i9
Although the ultra-performance models in the Intel Core i9 range seem incredibly exciting (and they are!), they are a bit overkill for most users. Intel markets those at pro-gamers, designers, content creators, developers, and more, and for a good reason. Most of the time, a top-tier Intel Core i7 CPU will do the job and save you a fair whack of cash in the process.
However, each to their own, of course, and if you can afford an Intel Core i9 CPU for your gaming rig, buy it and enjoy the incredible experience.