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What makes a computer faster?

Well, obviously it's the colour you paint the case; red is faster, black is slower, grey is the slowest. Obviously! You can apply the same logic to LED's inside your case. But no, of course not. It's got to be something involving technical terms! Traditionally the CPU (central processing unit) speed was the main thing determining computer speed, with the RAM (random access memory) being a secondary but important measure. Motherboard speeds entered into it somewhat as well.

But that was the 90's and this is now. Now things are a little more complicated. CPU speeds are no longer important, as we hit the limit of how fast we could push electrons through silicon a decade or so ago. But the number of cores the CPU has does matter. Think of cores as multiple CPUs within the same CPU. As the years have progressed software has become more adept at taking advantage of the multiple cores inside most CPUs, so that in general a CPU with 4 cores can outperform a CPU with 2 cores by a factor of around 50%, if the software takes advantage of it. And of course you have newer CPUs with much larger numbers of cores.

Then you have CPU architecture, which, without going too heavily into it, is the way in which CPUs deal with multiple incoming instructions in the most efficient way possible (greatly simplifying here) between the cores. This has improved strongly over the past decade. RAM speed isn't really a factor anymore. Originally it played a role in how fast the CPU could go, but that has since been decoupled with advances in technology. The amount of RAM you have certainly plays a role, but the majority of consumers will experience no performance difference over 4GB (gigabytes) of RAM. Motherboard speed also plays a minor role, with about a maximum of 5% total speed being attributable to it.

But all of these performance differences don't matter much for the vast bulk of consumers who only use their computer to access email, browse the internet and edit office documents. For those, the greatest increases in speed have come from storage performance. Back in the day, HDD's (hard disk drives) were fairly slow and operating systems made a point of accessing them as little as possible. But with the advent of SSD (solid state drives) and NVME drives, storage performance has increased by a factor of 10x and 100x respectively. What this has meant is that operating systems such as Windows have become careless and lazy about how they access drives; you'll find Windows 10 and 11 operate extremely poorly on old-school mechanical hard drives when compared to Windows 7.

So in summary: for most consumers so long as the CPU has more than 1 core, at least 4GB of RAM, and a SSD or NVME drive, they'll be fine. For gamers and whatnot a more advanced CPU, graphics card or a greater quantity of RAM may be warranted. So for those struggling with the speed of an older machine, consider upgrading it to a solid state drive (about $60 for a 512GB one), rather than replacing the whole machine - you'll get to keep your current setup with a massive increase in speed but without the increasing cost of a new computer.

(By the way, Windows 11 does run on older hardware now; Microsoft changed the rules on that one following consumer backlash. You'll have to tweak a parameter in the operating system, but your older computer will still work fine post-2025 if this is performed).

- Matt Bentley, computer expert at Bentley Home PC Support.
Email info@homepcsupport.co.nz or phone 0211348576.

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