We've already covered choosing between Intel's mid-range Core i5 processors and the more powerful Core i7 line. But what if you're looking for something a little more efficient, or just need to work within a smaller budget? You might be in the market for a Core i3 processor (or a laptop or desktop equipped with one). That said, there's still a bit of overlap between the entry-level Core i3 and the Core i5. Let's break down the pros and cons of each.
The following is meant to be a handy buying guide for choosing between a Core i3 or i5. It should apply both to pre-built laptops and desktops and to those who need a processor for their own desktop builds. Intel has dozens of Core processors across the various lines and generations, so comparing individual processors to one another may not be ideal -- here's a general guide to choosing between the two.
Clock speed
Clock speed -- the megahertz or gigahertz rating for each core of a processor -- used to be the surest way to get a feel for performance. That's no longer true, unless you're comparing two processors in the same family, with the same architecture. Thankfully, the Core i3 and i5 are very similar under the hood, so comparing clock speed remains valid.
Core i5 processors are generally (but not always) clocked higher than their Core i3 counterparts, and so have the ability to handle intense calculations more quickly. You'll be able to see that when performing complex single-thread tasks, like rendering a large Microsoft Excel file or applying a filter in Photoshop. In almost all situations, Core i5 processors will perform faster than comparable Core i3 processors.
Processors equipped with Intel's Turbo Boost feature can increase their clock frequencies under high workloads, allowing a computer to speed through a particularly taxing process. The Core i5 series has featured Turbo Boost on some models since the start of the Core nomenclature in 2010, while almost zero Core i3 processors are equipped with Turbo Boost as of the fifth generation. This means Core i5 processors often perform even more quickly than the base clock speed suggests.
Dual-core versus quad-core
Because Core i3 processors are the low-power, economical entries in Intel's lineup, all of the CPUs as of the fifth generation have been equipped with two cores on both desktops and laptops. Core i5 processors are more expensive and powerful. Even so, the smaller and more power-efficient laptop versions of Core i5 processors are exclusively dual-core, whereas desktop Core i5 processors with more generous size and power restraints are almost always quad-core.
Desktop users don't need to worry about battery life, so a more powerful Core i5 processor is a good choice.
Programs need to be written to take advantage of multi-core processors. Today, most software that benefits from high processing power does this, so in general, high-power games and programs will run faster on a quad-core processor. That gives the Core i5 desktop chip a substantial advantage over its Core i3 counterpart.
Some (but not all) Core processors also feature Hyper-Threading, a proprietary Intel technology that allows more effective scheduling of CPU tasks, especially for multi-core architectures. While this technically makes the whole computer faster, it's most visible on those high-intensity programs like media editing. Hyper-Threading has been available on some Core i5 processors as of the second generation (Core i5-2XXX CPUs and later) and on Core i3 processors as of the fourth generation (i3-4xxx and later). Not all processors in the same generation or those that follow have Hyper-Threading enabled, and system builders need to make sure that their motherboard BIOS supports Intel's Hyper-Threading technology to see the benefit.
Power draw
Core i5 processors are generally more powerful than Core i3 processors, but that also comes with a higher draw on a computer's electricity. Some Intel processor models ( those with the M, U, and UM labels in particular) are specifically designed to be power-efficient, but generally speaking, comparable i5 processors will draw more power for similar tasks than Core i3 processors.
Road warriors may prefer a Core i3 processor for its lower battery drain.
That's not a huge concern for most desktops since the system's uptime isn't constrained by a battery, but laptop users may want to consider processors with lower wattage ratings to save power.
However, with a lower electrical load, an i3 may be a poor choice if you intend to use a laptop for high-intensity processes -- a Core i5, which completes those processes faster, might use a similar amount of electricity and offer a faster computing experience overall.
Heat
The more watts a processor draws and the higher its clock speed, the more heat it generates. For the same reasons outlined in the power draw section above, Core i3 processors tend to run cooler than their i5 counterparts. This usually isn't a concern for desktops (unless you're building a powerful gaming or media machine), but laptops with more powerful CPUs may become uncomfortably warm during heavy use.
Price
Core i5 processors are more expensive than Core i3 processors. When buying a processor separately for a desktop build, the price varies based on processor generation and capability, but you can generally expect to pay $50-100 more for an i5 processor versus the similar model of the i3 family. The price may with extra features like Hyper-Threading and extra L2 and L3 cache, performance-enhancing options usually not offered on low-power processors.
Laptop processors generally aren't user replaceable, but when manufacturers offer the choice between Core i3 and Core i5, the upgrade options usually start at about $100. These can be more expensive if the processor upgrade is linked to other components, such as more RAM, more storage, or a screen with a higher resolution.
Conclusion
Core i3 processors aren't as fast or powerful as Core i5 processors, but they're more than capable of running the vast majority of standard computer programs with ease. If your plans for a new computer are restricted to everyday tasks like web browsing, editing documents, or even web video, a Core i3 processor will serve you well, and the extra cost and power draw of the Core i5 may not be worth it. If you're a laptop shopper looking for a cheaper option or you're hoping to save electricity, you may be better served by a Core i3 processor.
Bill Roberson/Digital Trends
If you plan to use your computer for high-end 3D gaming, media editing, or 4K video playback, you want all the processing power you can get. The extra expense and power draw of a Core i5 processor is worth the upgrade, especially when paired with more powerful components like extra RAM or a discrete graphics card. If you're on the fence, the Core i5 may be the safer bet. It will run basic programs well for now, and you can try more taxing activities in the future, confident that your computer will be up to the task.
If you want to compare specific models of Core i3 or Core i5 processors against each other, try the excellent comparison tool at CPUBoss. Just enter the model number of two processors, and the tool will show you side-by-side technical specifications, performance benchmarks, and prices. Intel's ARK database, which lets you search for processors based on series, architecture, or specific features, is also a handy reference.
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