The world of CPUs is bewildering, so let us help you make sense of it
When building a new system or upgrading an existing one, it’s easy to just opt for the most powerful processor you can afford, but is that the best decision?
Spending £350 on an Intel Core i7-5820K may well let you play the latest games, fly through video and image editing and look nice on the benchmark league table, but it’s overkill if you’re only ever going to use your computer for basic web browsing.
Likewise, opting for a dirt cheap AMD Sempron 2650 at just £23 isn’t going to get you very far for when No Man’s Sky is released in June.
You need the right processor for the right job. Sure you can future-proof yourself, to some degree, but you’ll need to be wise when buying a new processor, because you don’t want spend big, on the off-chance you’ll play a demanding game sometime in the future. There’s no single right or wrong answer in a situation like this, it all depends on how much you have to spend, what you plan to use the computer for, and any possible future upgrade potential.
Let’s begin by looking at the cheaper end of the market.
Entry level Intel
When we say entry level, we’re referring to basic desktop computing duties. Word processing, browsing the internet, watching videos and perhaps some lightweight gaming fall into this category, but you can also get away with minor video and photo editing.
As for prices at this level, we’re thinking of a range from £30 through to £75. We could drop the maximum price down a bit, but with £75 as the ceiling for the entry level, we can neatly move into the mid-range processors without too much of a price or performance gap between the brackets.
Intel has always been a little more expensive that its competitor AMD, but generally its processors offer a bit more in terms of performance. Entry-level Intel processors do tend to outperform entry-level AMD CPUs, but you could be paying anything up to £15 more for a gigahertz more in clock rates.
Clock speeds, though, aren’t everything. Chip architectures, cache, cores and other factors determine a better processor for your money.
Celeron G1840 2.8GHz
The entry level Intel processor we’ve picked to begin with is the popular Celeron G1840. This dual-core CPU has a clock speed of 2.8GHz, a TDP of 53W, a maximum memory bandwidth of 21.3GB/s, and it can be bought for as little as £36.48 from Ebuyer.
It’s actually not a bad processor. With a 22nm Haswell manufacturing process, 128KB L1 cache, 512KB L2 cache and a 2MB L3 cache, it can keep up with most users’ demands, especially those we’ve defined as ‘entry level’.
The HD graphics are pretty weak for intensive 3D gaming, CAD work or shifting through video editing footage. The GPU side of it has just a 350MHz base clock speed (turbo of 1050MHz) and support for DirectX 11.1, so don’t expect anything too complex above 1080 or even 720 resolutions. But it does support Intel Clear Video HD technology and Intel Wireless Display, so it’s not all bad on the graphical front.
Pentium G3250 3.2GHz
The Pentium G3250 is a slightly younger processor than the Celeron G1840, by a few months, at least. It’s another dual-core processor, running at 3.2GHz with a TDP of 53W, a maximum memory bandwidth of 21.3GB/s, and it can be purchased for around £53.
It’s not hugely different to the Celeron G1840, other than the 15% higher clock speed, 3MB L3 cache and a slightly higher score from various benchmarks. The HD graphics are much the same too, with the exception of a higher turbo clock speed of 1100MHz.
It’s a solid entry-level performer and one that’s slightly better than the Celeron chip.
Pentium G4500 3.5GHz
At around the £75 mark we have the best of what we regard as the entry-level Intel processors: the Pentium G4500.
It’s a fairly recent processor, released in July last year, and one of the first Intel Skylake desktop CPUs to hit the market. It has a clock speed of 3.5GHz, a TDP of 51W, maximum memory bandwidth of 34.1GB/s and a price of around £73.
It’s actually an interesting processor for the money. It’s unlocked, which means you can overclock it to speeds up to 4.9GHz with an air cooler, and higher if you have a liquid cooling solution. Obviously ,this means you can up the clock speeds as you see fit in the future, and it’ll give you a bit more use out of it, as you begin to do more with your system.
Although the clock speeds for the integrated graphics are the same as that of the Celeron G1840, the better 14nm manufacturing process and better HD 530 processor graphics mean you’ll be able to enjoy some (although limited) 3D gaming. And other elements such as video and photo editing will be quicker too.
In short, for an extra £20 on top of the Pentium G3250, the Pentium G4500 is a pretty good choice.
We won’t get into an AMD-versus-Intel debate here, but AMD does make some pretty interesting entry-level processors.
If you’re looking for a good entry-level AMD processor, then you won’t go far wrong with the A4-4000.
This is a dual-core 3GHz processor with a turbo clock speed of 3.2GHz, a 32nm manufacturing process, a TDP of 65W and a maximum memory bandwidth of 21.3GB/s. In terms of price, you can pick one up for as little as £25.
It was released in May 2013 and is a part of the Bulldozer A-series family of AMD processors. Although the Bulldozer family didn’t hit it off quite as well with the press at the time as AMD had hoped, for basic tasks it’s a perfectly capable CPU.
Interestingly, the A4-4000 features an integrated Radeon 7480D GPU with a base clock speed of 724MHz. This makes it a somewhat better graphical CPU companion than entrylevel Intel processors.
You can also overclock this processor (although we’ve never tried it with this particular model) to a possible 4GHz with air cooling.
Compared with the Intel equivalent, the AMD A4-4000 probably wins but only slightly. The clock speeds of the A4-4000 are better than that of the Celeron G1840, as is the integrated graphics technology. However, the manufacturing process is better on the Intel model, which improves its results across numerous benchmarks. In the end, though, that price of just £25 is simply too much to resist, which means you get a lot more performance for your money with the A4-4000.
Moving up through the ranks to the middle of the entry-level AMD processors, we have the extremely capable A6-6420K.
This unlocked dual-core processor has a base clock speed of 4GHz, a turbo clock speed of 4.2GHz, a 32nm manufacturing process, TDP of 65W, a maximum memory bandwidth of 29.9GB/s and a price in the region of £45.
Again the integrated graphics on this Bulldozer family processor are quite impressive, this time offering a Radeon 8470D. What this means to the user is a better than average level of performance.
However, there are plenty of benchmark results available that place the Intel equivalent (in this case the Pentium G3250) higher than the A6-6420K. This again is down to the better manufacturing process of the Intel chips and the technology used, but there’s not a huge amount in it.
There’s not much in the price either, so it’s all down to those extra megahertz and the fact that they’ll do more good at the sort of processing an entry-level computer will need.
This is the first quad-core processor in the entry-level section, and it’s quite an impressive CPU to finish this price bracket with.
The A8-7650K has a base clock speed of 3.3GHz, a turbo clock speed of 3.8GHz, TDP of 95W, a maximum memory bandwidth of 34.1GB/s, and you can buy one for around £73.
As before, AMD’s integrated graphics solution is a more appealing factor for the A-range of processors. In this instance, the A8-7650K uses a Radeon R7 for its integrated solution, which is a pretty good graphics solution for the entry-level customer to have in their system.
Overclocking is of course possible, with speeds of up to 4.9GHz using a liquid cooling solution and 4.3GHz using more traditional air cooled systems.
In comparison to the Pentium G4500, the A8-7650K performs well, beating it in most benchmark results.
The A8-7650K is slightly cheaper, which means you’ll get a little more performance for your money. But it does have a bigger TDP, and the manufacturing process of 28nm isn’t anywhere near as good as the Intel offering.
Having said that, it’s a fine entry-level processor for AMD motherboards.
A mid-range processor should be capable of covering a multitude of uses. There should be more cores on offer, allowing it to work as a virtual machine host. Also, gaming shouldn’t be an issue, with it being more than capable of helping push the latest titles along in conjunction with a decent graphics card. In short, it shouldn’t cause a gaming bottleneck like an entry-level processor would.
Other duties include better video and image editing, as well as more complex computing work such as CAD and other 3D duties.
As for the price bracket for the mid-range processor, we think between £75 and £150 sounds reasonable enough.
Core i3-4160 3.6GHz
Let’s open the mid-range Intel processors with the i3-4160. This fourth-generation dual-core processor has a base clock speed of 3.6GHz, a TDP of 54W, 22nm manufacturing process and a maximum memory bandwidth of 25.6GB/s. It’ll set you back around £95.
With dual-core and Hyper-Threading, the i3-4160 manages to hold its own, even against i5 chips. It’s a good processor, with Intel’s improved manufacturing process and technology, along with integrated Intel HD 4400 graphics.
Granted, you wouldn’t expect the HD 4400 graphics to keep up with a dedicated graphics card, but for watching HD video, even up to 4K resolutions, it’ll do the job well enough.
Core i3-6300 3.8GHz
The Core i3-6300 is another dual-core Skylake architecture processor with a clock speed of 3.8GHz, TDP of 51W, 14nm manufacturing process, a maximum memory bandwidth of 34.1GB/s and a price in the region of £125.
It’s a fairly new processor, having been released in September last year, and is one of the group of new i3 chips that’s often found in cheaper gaming builds. Overclocking is possible, with speeds of up to 4.4GHz being reported with air cooling.
In comparison to the i3-4160, the i3-6300 certainly performs better across the board. Even the integrated HD 530 graphics aren’t too bad.
Core i5-4440 3.1GHz
The top chip for the mid-level is a difficult one to pick. We could go for the top i3 CPU, which would leave a few pounds free from the £150 limit we’ve set ourselves, but then we’d lose out on the low end of the i5s.
As it happens, we went for the i5-4440, a 3.1GHz base clock processor with a turbo clock of 3.3GHz, a TDP of 84W, 22nm manufacturing process, maximum memory bandwidth of 25.6GB/s and a price of £149.99.
This Haswell quad-core CPU provides a decent amount of grunt for processor-heavy applications. It offers excellent all-round performance across a number of benchmarks, reasonably low power consumption for the level of performance, and again the HD 4600 integrated graphics aren’t too bad.
The mid-range area is where AMD starts to shine, with a slightly lower cost for a processor with a higher clock speed.
The AMD FX-6300 is a good starting place for the AMD mid-range line-up. This CPU is pitched perfectly for the mid-range user, with a 3.5GHz base clock and a turbo clock speed of 4.1GHz.
Aside from the slightly higher clock speeds (compared to the first mid-level Intel entry), this Piledriver processor has a TDP of 95W, a 32nm manufacturing process and a maximum memory bandwidth of 29.9GB/s. Not bad for a processor that costs just £82.
One good point about the FX-6300 is its overclocking potential. There are users who run this processor at around the 4.8GHz mark with air cooling, pushing it to 4.9GHz and beyond with liquid cooling and more elaborate setups.
The six cores make for a higher degree of computing performance, especially for building virtual machines, but the lack of integrated graphics does put this processor in something of a negative light.
Having said that, with an 8MB L3 cache, more cores and higher clock speed, it’s a good choice for power users on a budget.
A10-7870K Black Edition 3.9GHz
The middle area of the mid-range AMD CPUs is a tricky place. On one hand, there’s the FX range of AMD processors, and on the other, we have the top-of-the-range A10s.
In the end, we went for the A10-7870K Black Edition, with a base clock speed of 3.9GHz, turbo clock speed of 4.1GHz, TDP of 77W, 28nm manufacturing process, maximum memory bandwidth of 34.1GB/s and a price of £116.
This quad-core Steamroller processor is a great choice for those who want raw computing power at a reasonable cost. The unlocked CPU can hit overclocked speeds of 4.8GHz with air cooling and beyond for liquid cooling.
As with the rest of the A-series of processors, the integrated graphics for the A10-7870K are pretty impressive. The Radeon R7 (also in the A8-7650K) is capable of dishing out some decent visuals and will outperform the equivalent Intel model we’ve put in the middle of the mid-range list.
For a top mid-range AMD chip, we have a few options, but this time around we went for the FX-8370E.
This eight-core processor has a base clock speed of 3.3GHz, a turbo clock speed of 4.3GHz, a TDP of 95W, 32nm manufacturing process, a maximum memory bandwidth of 29.9GB/s and a price of around £150.
As with the other FX model, this Vishera CPU doesn’t have an integrated graphics solution, but it makes up for that with eight unlocked cores and an overclocking potential of up to 4.9GHz with air cooling.
In comparison to the Intel i5-4440, the FX-8370E is about even in the many benchmarks other testers have put them through. The higher turbo clock speeds and overclock speeds lean in the FX-8370E’s favour, but the lack of an integrated GPU could limit it and push the i5-4440 up the list.
It’s also slightly more expensive than the i5-4440 we’ve used in comparison, but only by a few pounds. Still that could be the deal-breaker for users on a strict budget. Other than, the AMD FX-8370E is a superb mid-level processor.
What should a high-end processor be capable of? Well, pretty much everything. You should expect to be able to play all the latest games – in conjunction with a similar dedicated GPU, of course. And you should be able to edit video and images without having to hang around too long for the processor to catch up with you.
Other duties would include a more powerful virtualisation, with more dedicated cores for the virtual machines installed. And since we’re now in the high-end of the scale, we’d expect such a processor to easily cope with streaming gaming across a network, as well as other streaming media.
As for the price bracket, we’ll start at £150 and stop at £300. We could go a lot higher, but we want to keep things at a reasonable level for home users.
Core i5-6400 2.7GHz
This four-core processor makes for an ideal start for Intel’s higher-end CPU range. It has a base clock speed of 2.7GHz, a turbo clock speed of 3.3GHz, a 14nm manufacturing process, a TDP of 65W and maximum memory bandwidth of 34.1GB/s. It’s available to buy for around £160.
In terms of performance, it’s not too bad, but one interesting feature of this model, as with other instruction set extensions in the Skylake range, is the Intel Software Guard Extension or Intel SGX. This allows certain programs to create a protected area in the system memory for user details, data or code. Essentially, this will hide sensitive data from any spyware that could infect the system.
That aside, the i5-6400 is a good enough processor for most higher-end users, and its potential for extra security makes it ideal for home servers.
Core i5-4690K 3.5GHz
You may be familiar with the Intel Core i5-4690K, as it’s the darling of mid-range gaming PCs. This 3.5GHz CPU has a turbo clock of up to 3.9GHz, a TDP of 88W, a 22nm manufacturing process and a maximum memory bandwidth of 25.6GB/s. It can be bought for around £200 (although we’ve also seen one for sale for as little as £160).
It’s a four-core processor that offers some of the best gaming performance per pound from any CPU currently available, which is why it’s a popular choice for system builders. It’s only slightly behind its big brother the i7-4790K in terms of computing performance, with plenty of benchmarks available for you to look up.
Since the CPU is unlocked, overclocking is one of the best features of the i5-4690K. We’ve seen clock results of 4.5GHz and beyond in some systems, using both air and liquid cooling.
It’s a fantastic processor and one of the best you can buy for your high-end system.
Core i7-6700K 4GHz
The top end of our Intel scale finishes with the Core i7-6700K. This CPU has a 4GHz base clock with a 4.2GHz turbo clock speed, TDP of 91W, 14nm manufacturing process, a maximum memory bandwidth of 34.1GB/s and an eyewatering cost of £298.
It’s a quad-core CPU with eight threads unlocked and capable of hitting overclocked speeds of 4.9GHz and beyond, depending on the cooling setup used. It’s a high-end CPU that delivers some of the best benchmarks and performance outside of the Intel Extreme Edition models.
It’s certainly expensive, but you’ll notice a huge performance leap from an older i5 if you were install one of these.
Beyond the i7-6700K, there’s the i7-5930K at £540 and the i7-5960X Extreme Edition at £899. As we said, though, that’s entering the money-is-no-object realm, which we’ll leave for you to investigate.
AMD has some pretty good high-end processors on offer, with high levels of performance and a good pricing structure too. But its main focus is generally on the mid to entry levels, with Intel dominating the mid to high-end levels.
The FX-9370 is a 4.4GHz CPU, with a turbo clock speed of 4.7GHz, TDP of 220W, 32nm manufacturing process, maximum memory bandwidth of 29.9GB/s and a price of £166.
It’s an eight-core processor that’s unlocked and has some impressive overclocking potential. Expect overclocked speeds of up to 5.2GHz with an air cooler and probably higher with a liquid cooling solution.
In comparison to the Intel i5-6400, it performs well. The only exception is the lack of integrated graphics, but that’s made up for with more core and higher overall clock speeds.
It’s certainly a good processor and a favourite for virtual machine users.
Moving up the list, we have the AMD FX-9590, a 4.7GHz CPU with a turbo clock speed of 5GHz, TDP of 220W, 32nm manufacturing process, a maximum memory bandwidth of 29.9GB/s and a price of £180.
This is another eight-core, eight-thread CPU with a huge overclocking potential of 5.2GHz or more, depending on the cooling used. There’s not a lot in it in comparison to the FX-9370, other than a slight rise in clock speeds.
However, it’s not up to tackling the i5-4690K and loses out in almost every benchmark test. Still, it’s a good choice for power AMD users.
There’s a lot to find, no matter what you’re looking for or how you much you want to spend. Of course, processors change fairly rapidly, so this list could well be out of date within a few months. Spend enough, though, and you can give yourself some future-proofing. Whatever you do, make sure you get the processor that’s right for you, and not what makes the most money for the manufacturers.