We look at whether you really need to get a new CPU
Upgrading your processor is always a big deal, and in many systems it's the most expensive upgrade you'll even make - not just because CPUs can be expensive, but because it often requires you to buy a new motherboard and potentially new RAM, and maybe even a new PSU just so it can happen! In many cases, a CPU upgrade isn't a simple old-for-new swap; it's a major piece of invasive surgery on your system.
So how do you know when a CPU upgrade is worth doing and when it should be avoided?
Before you upgrade a CPU, it's a good idea to rule out any other upgrades that might help. If your problems are that your system boots slowly and programs take a long time to load, an SSD would almost certainly provide a bigger performance leap than a new CPU would, since modern CPUs are so fast that the hard drive frequently slows them down far more than their own workload does.
If you already have an SSD, then more RAM is also useful for general system performance. Extra RAM helps speed up application usage, especially when multi-tasking, and makes things like mediaediting smoother and quicker by keeping more data in the fast-access memory. Unless you have more than 8GB of RAM, you should see a fairly noticeable improvement in your system's general performance by putting more memory in it.
If you're planning to upgrade your CPU to make games run better, then a CPU upgrade might be useful, but before you spend any money, be aware that it's almost overwhelmingly a better idea to look at upgrading your GPU first. A game's graphical output is what makes up the majority of its drain on a system's resources, but improving a CPU has only a negligible effect on visuals compared to improving the GPU. If you get a new GPU you improve the visuals and free up any CPU resources that were being diverted to graphics for other types of processing, so there's a two-step improvement.
The exception to this rule is if there's a particular disparity between your CPU and GPU. If you have a low-end gaming CPU (such as an Intel Core i3) but a high-end GPU, then it's probable that your processor is bottlenecking the GPU and your game would see immediate benefits from a CPU upgrade, but unless there's an obvious difference between the capabilities of the two devices, a GPU upgrade is more likely to improve your game.
In most cases, the only time it makes sense to upgrade the CPU before any other component is if you're having trouble with explicitly CPU-intensive applications. This might include video and audio encoding, 3D rendering and anything that involves number-crunching, such as Bitcoin mining, distributed systems and specialist scientific/mathematical software. And lastly, if you're playing a game that is intensive on the processor but not the graphics, such as Elite IV.
If those sound like oddly specific examples, that’s because they are. It's actually quite rare that a CPU is the cause of a system's bottleneck compared to the rest of its hardware, and the disparity is even more pronounced outside the gaming sector. With games it's a fight to keep the GPU and CPU up to each other's standards, but almost any other type of home computing is limited by some other factor.
If you're worried that your CPU is the cause of a system bottleneck, you can use a program like HWMonitor (www.cpuld.com/softwares/ hwmonltor.html) to get some hard stats on the subject. Locate the statistics for your CPU and run whatever process you think is being slowed down by your hardware. If your CPU starts running at 100% capacity for extended periods while slowness is occurring, you've confirmed it.
To check this in the free version, look under the CPU and read the 'UC utilizations’ values. The first value is the current usage, the second is the low and the third is the high. It will probably hit 100% during any slightly intensive task, so don't worry about that; the problem is if the first reading hits 100% and stays there. If you want to monitor the situation more closely, the Pro version of HWMonitor offers graphs of performance too.
Of course, we've only looked at this question from one angle so far: what outcome do you want? An alternative discussion can be had if you consider what's economically viable.
If you have a low-end Intel CPU, for example, you might find that your socket allows you to move up to a vastly more powerful chip without changing any other components in your system. A Pentium or Celeron-based system has a motherboard that will support up to a Core i7 chip, provided it uses the same generation of socket. That's an enormous leap in system performance without any further upgrades required.
It's true that there's a small chance you'll need a new PSU to power the chip, but compared to a high-end graphics card (which will almost definitely need a new PSU) or a chip upgrade that requires a new motherboard (and possibly new RAM) to be compatible, a new CPU of the same generation is suddenly a rather economical way to see a general leap in your system's performance.
At the opposite end of the spectrum, a good time to know that it definitely is time to upgrade your CPU is if you've taken the current platform as far as it can go. If you're running a Sandy Bridge Core i5, even shelling out for a Sandy Bridge Core i7 isn't going to result in a major performance increase compared to the latest platform.
If you're running the best AMD APU but it's still not enough, you have no choice but to seek out a faster chip, and that means looking at another platform. While we might sound reluctant to recommend a CPU upgrade in general, it's only because it's often an expensive way to fix the wrong problem. The good news is that any CPU upgrade - even a small one - will definitely improve the way your system works. It might not be the best way to get a performance increase in the specific area you want to improve, but it is virtually guaranteed that you'll get one, and as an added bonus, that improvement will affect almost everything you do as well.
So look at it this way: more RAM might help you multi-task better, and a new GPU might speed up your games, but a fresh CPU will do all that and more. The truth is that due to the number of factors involved in keeping PCs running quickly and smoothly, it's hard to give a comprehensive advice on whether or not to upgrade a system. That said, there's some good news: while it's almost impossible to say whether or not you should upgrade your PC, there’s almost no circumstance under which you shouldn't. So if it feels right, give it a try. Things will definitely get better!