Core i3 vs Core i5: What's the Difference?

The first Intel processors to use the Core i3/i5/i7 naming scheme were the Nehalem based products that arrived in 2008. Intel focused on the high-end Core i7 products first and then filled out the line.

Now that Intel has launched a new processor architecture, called Sandy Bridge, Intel has once again been placed into the position of announcing new processors. However, unlike before, Intel is releasing a full line of i3, i5 and i7 processors right away. This makes the Core i3 vs. Core i5 question immediately relevant.

The previous Nehalem line of products could become rather confusing to describe because there was a wide variety of products with different codenames available. This was the result of Intel's gradual release of different parts of the Intel Core lineup. The Core i3 and i5 dual-core processors, released later than the original quad-core Core i5 and i7 processors, were based on a slightly tweaked architecture.

Because Sandy Bridge is being launched across the entire brand, however, there are no longer different sub-sets of the architecture to talk about (at least for now). The features that are enabled or disabled is Intel's choice.

There are several major differences when comparing Core i3 vs Core i5 Sandy Bridge processors, and they're more defined than they were before. The first is the number of cores. The new Core i3 processors are dual-core only, while the new Core i5 processors are quad-core only. Another major different is Turbo Boost, which is disabled on Core i3 processors but enabled on Core i5 processors. However, Intel Core i3 processors have hyper-threading support but Core i5 processors don't offer this feature.

Besides these points, there are two minor differences. Core i3 processors don't support Intel's vPro virtualization technology and don't support Intel's AES encryption acceleration technology. Intel Core i5 processors support both.

The most importance new feature added to Intel's Sandy Bridge processors is the inclusion of an IGP on the processor. Intel did this before with Core i3 and some Core i5 processors, but the IGP was still separate from the processor itself - the IGP and CPU were placed on the same piece of silicon, but didn't physically work together.

Now Intel has taken the IGP integration a step further and worked the IGP into the CPU architecture. It even shares cache with the processor. What this means, in practical terms, is that the on-board graphics of Intel's new processors are superior to anything they've offered before. It also enables Quick Sync, a video transcoding feature that provides blazing performance when converting videos to a different format.

Intel is offering two different types of IGPs on its processors. The 2000 has 6 execution units, while the 3000 has 12 execution units. Obviously, the later is quicker. Intel hasn't tied the IGP that you receive to the type of processor you choose, however. Instead, it has tied the 3000 series IGP to the "K" series processors. If you see a "K" at the end of the processor's name, it has the 3000 series IGP. So far, Intel doesn't offer a Core i3 K series processor, but that could change in the future.

The staggered release of Intel's previous Core i3/i5/i7 products also resulted in a staggered release of processor sockets and their related chipsets. First came LGA 1366 processor socket, which was tied to some Core i7 processors. Then Intel confused things by releasing the LGA 1156 socket, which was made available on several different chipsets and processor types. Choosing the right socket and chipset for a processor wasn't easy.

Intel has now clarified matters by releasing a single processor socket and two processor chipsets alongside Sandy Bridge. The new socket is LGA 1155, and it isn't backwards compatible with anything Intel has previously offered. The new chipsets are P67 and H67, with the P variant being performance-oriented and the H variant targeted at general use. The main difference is that P67 allows for processor overclocking, while H67 does not. P67 also offers 16 additional PCIe lanes.

Both Core i3 and i5 processors are compatible with either chipset, so the processor you choose has nothing to do with the chipset you choose. For now, at least - Intel is expected to release a new socket and chipset alongside a faster variant of Sandy Bridge later this year.

In my last article about Core i3 vs Core i5 processors, I spent my verdict talking about how muddled the waters were when trying to compare i3 and i5 processors. This, thankfully, is no longer the case. The differences between the processors are clear. The i5 is quad core, the i3 isn't. The i5 has Turbo Boost, the i3 doesn't. The i3 has hyper-threading, while i5 doesn't.

Overall, the additional cores and the Turbo Boost feature on the i5 makes it a clearly quicker processor in virtually all usage scenarios. The catch, of course, is price - the least expensive i5 is about $50 more than the most expensive i3. I think that spending the extra money is worthwhile if you're a computer hardware enthusiast, but the average user with a tight budget will likely be fine with what the i3 has to offer.

Both the Core i3 and i5 are great processors, so the question really comes down to how much you have to spend. Fortunately, both processor lines use the same socket and are compatible with either of the new chipsets, so you can mix-and-match those to find a pricing and performance sweet spot.