Haswell Core i3 vs. i5 vs. i7 – Which is right for you?

Introduction

There are a few differences in features (notably Hyperthreading, cache size, and number of cores), but as we will show later in this article there is actually very little that differentiates an i5 CPU from an i7 CPU. The biggest thing that this naming scheme gives you is a starting place when choosing a CPU. If you use your computer for basic tasks like surfing the web, then an i3 CPU is likely a great choice. If you use your computer for a variety of tasks that require a bit more power (including gaming), than an i5 CPU might be a better choice. If you run multiple applications that require a lot of CPU power, then an i7 CPU is probably right for you.

Desktop CPUs

	Frequency	Turbo Boost	Cores	Hyperthreading	Smart Cache	TDW	Graphics
Core i7	2.0-3.5GHz		4		8MB	35-84W	Intel HD 4600
Core i5	3.0-3.4GHz		4		4-6MB	35-84W	Intel HD 4600
Core i3	2.4-3.6GHz		2		3-4MB	35-54W	Varies

Overall, the chart above can be summarized with the following:

1. The CPU frequency and thermal output (TDW) is largely not determined by the Core i_ name
2. Core i5 and i7 both have Turbo Boost while the i3 does not
3. Core i5 and i7 CPUs have 4 cores, while i3 CPUs only have 2
4. Core i5 CPUs lack Hyperthreading
5. Core i7 CPUs have more Smart Cache than i5 CPUs, which in turn have more cache than i3 CPUs
6. Core i5 and i7 CPUs have the same graphics, although the speed of that graphics will depend on the individual CPU. Core i3 CPUs have variable graphics depending on the price-point of the CPU.

So while i7 CPUs do have overall better specifications than i5 CPUs, there is actually quite a bit of overlap between the two except that i5 CPUs do not support Hyperthreading. Especially in terms of frequency and thermal output, the two lines really are not very different. For i3 CPUs, the main difference is that they only have two cores, a smaller cache, do not support Turbo Boost and have overall lower thermal output than i5 and i7 CPUs.

Mobile CPUs

	Frequency	Turbo Boost	Cores	Hyperthreading	Smart Cache	TDW	Graphics
Core i7	2.7-3.0 GHz		4		6-8MB	47-57W	Intel HD 4600
Core i5 Unreleased	1.5-2.8 GHz		2		3MB	17-57W	Intel HD 4600
Core i3 Unreleased	1.4-2.6 GHz		2		3MB	13-45W	Intel HD 4600

Currently, there are no Haswell Core i3 or i5 mobile CPUs available for consumers. The values in the chart above are our prediction based on previous generations.

Overall, the chart above can be summarized with the following:

1. There is a lot of overlap in CPU frequency and thermal output (TDW) between i3, i5 and i7 CPUs. Core i7 CPUs will have a slightly higher top-end frequency and wattage, while i3/i5 CPUs have lower bottom-end frequency and wattage.
2. All Haswell mobile CPUs released so far have both Turbo Boost and Hyperthreading (although i3 is likey to not support Turbo Boost)
3. Core i7 CPUs have 4 cores, while i5 and i3 CPUs (should) only have 2
4. Core i7 CPUs have more Smart Cache than i5 and i3 CPUs
5. All CPUs have the same graphics core (although i3 and i5 is unconfirmed), although the speed of that graphics will depend on the individual CPU

In this case, the main advantage of the Core i7 CPUs is that they have 4 cores, but at the same time they also have an overall higher thermal output. Core i5 and i3 CPUs are actually very similar to each other except that the i3 CPUs are likely to not support Turbo Boost and have slightly lower frequency and power draw than the i5 CPUs.

Conclusion