Intel core i3 vs i5 vs i7: Which One Should You Buy?

Intel’s processor naming is a big old box of chaos. I’m sure each individual naming decision made sense at the time, but taken in aggregate, it’s a cryptic mishmash of jargon, numbers and abbreviations.

To make sense of it all, we can split the processor model names into two parts. The first, and most important, is the brand which includes the i3/i5/i7 designation. These are the three big categories of chips and what we’ll focus on breaking down in detail. The remaining alphanumeric salad gives us some more info on that model’s specific capabilities which we’ll unpack further down.

Common Features

There’s a couple common factors between all chips in the Core family. The socket for processors in the same generation will always be the same. You don’t need a different motherboard for an i3 chip compared to an i5 or i7 chip. All chips also contain an integrated graphics package. For the sixth-generation Skylake processors we’re looking at an LGA1511 socket and HD530 integrated graphics.

Core i3 Processors


While the i3 processors are the lowest specced in the Core line-up, they’re a great jack-of-all-trades. They have only two physical cores, but hyper-threading helps make up for this deficit. Hyper-threading doubles the processor’s available threads, simulating four “virtual” cores. The L3 cache hits 3 or 4 MB, depending on your exact model, and clock speeds range from 2.7 to 3.9 GHz. You can expect prices between $110 and $140.

A jack-of-all-trades, however, is master of none. These chips are fast enough to be responsive to user input, but they don’t perform well at high-compute tasks, like video editing. They are fast enough to avoid bottlenecking a competent graphics card, which can make this a good chip for an entry-level gaming machine with a mid-range graphics card.

Core i5 Processors


Sitting roughly halfway between the i3 and i7 lines, the i5 chips grab some of the latter’s features while preserving the former’s thriftiness. You won’t see any hyper-threading on these chips, but you will see four physical cores, Turbo boost, and an overclockable model. The L3 cache also jumps up to 6 MB for desktop processors.

The Core i5’s Turbo boost allows the processor to temporarily increase the clock speed of one or more cores under load at the expense of greater power consumption and a reduction in processing power available to the other cores. It’s per-core overclocking, on demand.

Sixth-gen clock speeds vary between 2.2 and 3.5 GHz, with Turbo speeds up to 3.9 GHz, depending on the exact model you get. Prices range from $180 to $220.

Core i7 Processors


At the top of the heap are Core i7 processors. These chips include four logical cores, like the i5 series. They also include hyper-threading, creating eight threads over four physical cores. These chips bring the highest clock speeds in the lineup, maxing out at 4.0 GHz base clock speed and 4.2 GHz Turbo boost. The i7 chips come with a 8 MB L3 cache, and prices range from $300 to $340.

While these chips pack the most brawn, it’s probably more than most users can take advantage of. The i7s are awesome for high-compute tasks that can take full advantage of eight-core hyper-threading. But few programs check both of those boxes. Most games don’t use more than four cores, if that. Even Photoshop only benefits from more than two cores for specific filters and operations. If you’re not running Maya or Autodesk every day, you probably won’t see a performance increase to match the price increase over the i5 chips.

Nit-Picky Variations


Each processor brand also has its own variations, as indicated by the alphanumeric string after the brand name. My slightly-controversial option is that the specific details aren’t relevant, so here’s a high-level breakdown. The higher the SKU number, typically the faster the processor. The letters T, U and Y indicate a low-power-draw processor. K indicates a processor unlocked for overclocking, and P indicates a less-powerful integrated graphics stack. If you want to dig into the nitty-gritty on this, check out Intel’s documentation.

What Should I Buy?

Variations aside, the Core designations make it easy to figure out which processor you need. For most users, the i5 is a great chip, with a good balance between price and performance. The i3 is still plenty capable, and it’s excellent for budget machines since you’ll still get a good deal of bang for your buck. If you know your machine is going to see regular CPU-intensive workloads like 3D rendering, video editing or scientific modeling, then the expanded capabilities of the i7 chip are perfect.

Alexander Fox
Alexander Fox

Alexander Fox is a tech and science writer based in Philadelphia, PA with one cat, three Macs and more USB cables than he could ever use.

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