Intel Desktop CPU guide

So Intel's desktop lineup can be a bit of a minefield, I thought I would pop together a quick run through their range detailing the different features and hopefully give a good indication of a use case for each chip.

I'll start off with the standard desktop line, these are the bulk of Intel's desktop sales.
Across the range of desktop chip’s we have features such as integrated GPU’s, 16x on chip PCI-E lanes which can either be used as a single 16x lane for a single card or as two 8x lanes for Crossfire / SLI support, there are boards out there that offer more than two card support via the use of a PLX chip.

Pentium and Celeron

These are Intel's entry level, basic dual core chips, I wouldn't really recommend these for anything more than light gaming, they are aimed more at the basic Facebook / web browsing machine.

There isn't a huge difference between the Pentium and Celeron lines, on the latest Skylake chips the Pentiums have slightly more cache than the Celeron chips, 3mb vs 2mb.

The Pentium chips also have a higher clock speed and some models have a better spec integrated GPU.

One interesting thing that some of these chips support and the i5’s / i7’s don't support is ECC memory, why would you have this on lower end chips and not high end chips? Well the main reason is NAS devices, they don't need 4 cores or a high clock speed but ECC memory is essential in my opinion, I actually run FreeNas on a Pentium chip with ECC memory, bear in mind you will also need a motherboard that supports ECC memory as well.

Example of a standard Intel Desktop CPU, the i3 / i5 / i7 chips share the same package.

Core i3

The Core i3 is the entry level “Core” chip, these are dual core like the Celerons / Pentiums but have hyperthreading which will give you 4 threads, better for gaming, and there are models with higher clock speeds than the Celerons / Pentiums, some models also have an extra 1mb of cache.
These also support ECC memory so another good pick if you want a more powerful NAS system.

Core i5

This is the chip most gamers will likely have, these are true quad core chips but don't have hyperthreading.
For today's gaming at least for now 4 cores generally seems to be enough (DX12 / Vulkan may change that).
The cache on the i5’s is bumped up as well, Intel's latest Skylake chips have 6mb compared to the 4 / 3mb on the Core i3 chips.
Grab the K variant i5 and with a little tweaking in the EFI / Bios you can get some good overclocks.

Core i7

These are the highest end chips Intel offer, a lot of debate amongst the enthusiasts as to if there is any real world benefit over the i5’s for gaming, I guess it comes down to each individual's use case, Someone who streams their gaming may benefit from the extra threads for example.
So from a tech point of view this is the chip with all the goodies enables, it has four cores, the full complement of cache and hyperthreading, also if you're not interested in overclocking but want the best performance then they have higher clock speeds as well, though you will need to decide if a couple of hundred extra MHz is worth the premium.

HEDT CPU example, note the larger size

Core i7 HEDT (High-End Desktop)

Next up we have the second part of Intel's Core i7 line, given that these chips are effectively unlocked Xeons I would have prefered Intel called them something different like Core i9 for example to differentiate and avoid confusion but it is what it is.

Benefits here are more cores, Intel's Broadwell line of HEDT chips start at 6 cores and top out at 10 for example.

More on chip PCI-E lanes, there are two versions of these chips with 28 lanes and chips with 40, the 40 lane chips are great for anyone looking to do CrossFire / SLI as you can run two cards at full 16x or 3 cards at 8x8x8x.
This is also great for PCI-E storage, you can run M.2 / U.2 drives straight off the CPU’s lanes (motherboard supporting), why is this any better than running from a chipsets lanes?, Well for most users you won't notice a difference but for content creators / anyone requiring high throughput you might see a benefit, on the standard desktop range the drives connect to lanes on the chipset, the chipset then communicates to the CPU via DMI, which is effectively a 4x PCI-E link.
So imagine you are doing I/O intensive work, have a number couple of drives hooked up and a number of USB devices and you might see the link bottleneck.
Again though for most of us this won't be an issue.

Other variants

So, not wanting to make it to easy Intel makes it a little more confusing with a number of variants within the core lineup which I will briefly cover.

K Series

These are the chips that I expect most people to have or are looking at, these are the only chips in the range that support overclocking, along with the chip you will also need a Z series motherboard, for example with Skylake you would be looking at a Z170 based board.

T Series

These are the low power chips, the Skylake T series chips are 35w, great for a media PC for example that needs to be low noise, or a office machine that does not need a lot of horsepower.

P Series

Odd one these, they come in a number of TDP (Thermal design power) variants the only common feature along the line is the use of Intel's lowest end integrated GPU, the price isn't that much lower than the standard chips with the higher end GPU so I am not sure who these are aimed at, they might be chips with failed GPU cores that are being cut down and sold at a lower price.

Lowest end graphics, HD510 on the Skylake range for example

R / C Series

The first R Series chip I saw was the 4770R which was a chip that debuted in Intel's NUC lineup, it wasn't a socketed chip and was only available soldered to the board.
What made this unique is it came with Intel's highest end integrated graphics, and eDRAM, these made for powerful very small form factor machines, great for office use and media machines.

The C series were essentially the same but came in a socketed form factor, Intel released two of these with the Broadwell refresh a Core i5 and a Core i7.
Gamers were finding these to perform really well even compared to the newer Skylake chips, it's speculated the eDRAM helped a lot here, that said they are older chips now, use an older chipset and only support DDR3 and are quite expensive.

Conclusion

So thats a lot of CPU’s to choose from, to summarize I would recommend the following use cases :

Pentium / Celeron = Web / Office work and basic gaming
Core i3 = Entry level gaming / Office work
Core i5 = Great for gaming at most levels
Core i7 = Enthusiast’s
Core i7 HEDT = Enthusiast’s / SLI and Crossfire / Content creators

Hopefully this guide helps anyone looking to pick up a new CPU.