Best desktop computer specs: how to choose a cheap PC

A decent desktop PC can make those daily computing tasks a breeze. No more drumming your fingers impatiently on the desk while you wait for your computer to sort itself out. 

Make the wrong purchase and you could end up lumbered with a computer that's slow, has a poor-quality screen or is overpowered for your needs. 

In this guide, we'll run through the specifications to look for when buying a computer for different uses, along with the pros and cons of desktops versus all-in-one PCs. We also look at the accessories you need to complete your setup.

News, deals and stuff the manuals don't tell you. Sign up to our Tech newsletter, it's free monthly.

Below we've outlined two different sets of specifications for a tower or compact desktop computer. After that, we talk about the differences between all-in-one PCs and tower desktops so you can get an idea of how best to spend your money.

Best desktop PCs under £400: the specs you need

If you’re just looking to replace your tower or mini desktop PC, you really don’t need to spend more than £400 to get a desktop that’ll feel speedy when doing basic tasks like checking your emails, doing online banking or browsing the web. If you’re upgrading from a computer from a decade ago or more, you’ll be amazed at how fast cheap computers are nowadays.

All the advice here assumes you’re buying a new computer from a high street retailer or big online seller.

What to look for:

• Processor Intel Core i3 or AMD Ryzen 3 with at least four cores
• Graphics Whichever ‘integrated’ graphics card comes with the processor
• Ram 8GB as a minimum - don't go below this. If you can, it's worth spending more to get 16GB
• Storage At least a 256GB SSD and, optionally, space inside the case to move over an old hard drive from your previous computer. You may need to consult the manufacturer to find out whether there is a space inside for this
• Ports on the front for easy access At least two USB ports, 3.5mm headphone/microphone jack
• Ports on the back At least four USB ports, separate 3.5mm audio output and input jacks, HDMI.

All of the above can easily be found for under £400 at major retailers. 

Get tech confident for less

Get 12 months of tech support and buying advice for only £34.30, that's a 30% saving. Together we’ll show your tech who’s boss.

Join Which? Tech Support

Offer ends 16 Jun 25. Cancel anytime.

For unlimited 1-2-1 expert tech advice (including buying advice) - by phone, email, remote fix and in print, join Which? Tech Support. 

Already a Tech Support member? If you want 1-2-1 buying advice or need help with your tech, go to our online booking tool.

Best desktop computers under £500: the specs you need

If you work for multiple hours a day at a computer at home, it’s worth investing a little more to get something that completely meets your needs today and will serve you long into the future. The specs we’ve outlined below will work for anybody who needs a computer for multitasking and will also be a great pick for someone who edits photos from time to time.

• Processor Intel Core i5 or AMD Ryzen 5 ideally with six cores, but definitely at least four
• Graphics Whichever ‘integrated’ graphics comes with the processor
• Ram 16GB to ensure your computer is futureproof
• Storage At least a 512GB SSD although you can save money by opting for less
• Ports on the front for easy access At least two USB-A ports, a USB-C port, 3.5mm headphone/microphone jack, SD card reader
• Ports on the back At least four USB ports, separate 3.5mm audio output and input jacks, 1x HDMI.

You can easily get all this for under £500. If you compromise on Ram, you could squeeze in under £400 - but avoid doing this unless you really have to. The more Ram, the better.

Fancy something more portable? Take a look at our laptop reviews

Can I use a Mac mini to replace my ageing desktop PC or Mac?

The Mac mini 2024 launched at a very reasonable £599 for the most basic spec. For that money, you get the powerful M4 processor, 16GB Ram and 256GB SSD storage. 

Windows users might need to get some USB-A to USB-C adaptors, or use a small USB-C to USB-A adaptor to connect your mouse and keyboard. 

Most recent computer monitors will connect to the mini's HDMI connector. This will save you money if you have a screen that is worth keeping and you don't want to buy a new one. 

We put the tested Mac mini through our tough lab performance tests. For more information, see our expert Mac Mini review.

Where to buy a desktop PC

You'll usually find desktop computers sold at tech stores. To find out which retailers offer the best customer service, as revealed by actual shoppers, check out our pick of the best and worst tech shops before you go shopping.

Below, we've picked a few of the most searched-for retailers to help you decide where to get a desktop PC.

• AO stocks a wide range of desktop PCs starting from £329. It sells models from brands like Acer, ASUS, and HP. You'll find workstations, all-in-ones and a variety of gaming PCs - with many under the £500 mark.
• Currys offers desktop PCs from brands like Lenovo, HP, and Acer – selling tower PCs, all-in-ones and gaming PCs, starting from £279 for a typical tower desktop. You can get free next-day delivery on several PCs, and there are several options available under £500.
• Laptops Direct has several tower PCs, gaming desktops and all-in-ones available, starting from under £200 for some refurbished PCs. You'll find desktops from Dell, HP, Lenovo, and ASUS, with well over 50 options available for under £500. You can order several PCs with next-day delivery, but it'll cost you £10. There's also standard shipping available for £6.

Don’t buy desktop PCs with these specs

While it’s tempting to try to save money on a new computer, there are certain specifications that should be avoided. You’ll run into some of these when shopping on marketplace sites such as Amazon or eBay, but we’ve seen some models on big retailers that we wouldn’t touch with a barge pole.

Intel Celeron, Intel Atom, Intel Pentium 

While newer Pentium models aren’t awful, the price difference between them and a computer with a nice Core i3 is often under £50. As for Celerons and Atoms, however, these should be avoided as they’ll feel slow almost from the very start and feel even more lethargic as the years wear on.

4GB of Ram 

This is the smallest amount of Ram any Windows 11 computer can have, but these days it simply isn’t enough unless you’re conducting the very lightest of work on your device. The price difference between models with 4GB vs 8GB of Ram is normally small and it’s worth paying more for this. 16GB is even better.

Old processors 

This isn’t such an issue on big retailers, but if you’re buying from a marketplace such as eBay or Amazon, or from a discount site such as Wowcher, you should check the age of the processor in the device you’re buying. 

This is easy to do: simply copy the name of the processor and paste it into a search engine. Then click on the result that takes you to the processor maker’s official website. Within the data you should get a launch year, or a launch quarter (for example Q4 22 would be the fourth quarter of 2022). 

We’d say if the processor is more than six years old, it’s probably not worth buying the computer, even if it has Windows 11. If the listing doesn’t specify what exact processor is in the computer you’re buying, avoid it entirely.

Want more information about processors? See Intel processors explained

Desktop PC vs all-in-one

All-in-one computers are just that: it's the entire computer in one package including the screen and speakers. While there's a level of convenience to this form factor, when we've tested them in the past we have almost always found them underwhelming. 

The main reason for this is that manufacturers compromise on the screen and speaker quality to keep costs down. But even if you do get one with a good screen, the specs are more akin to laptops rather than desktops, so they're substantially slower than a tower desktop costing the same. So while there is a time and a place for all-in-one computers, buying a tower and then spending another £100 on a monitor (see our guide to the best monitors including cheap screens) is almost always better value.

Nonetheless, below are some key pros and cons to help you make your decision.

Advantages of a tower desktop PC

You'll find that they come in various shapes and sizes, from large bulky hulks that need to sit under your desk, to more discreet and stylish models that can be tucked away.

• More customisable The big plus point of a desktop PC is that the large, tower-style models can be easily adapted to suit your needs. You can pick the monitor you want and make more significant changes internally, such as adding more Ram, a new graphics card, or a more powerful processor. The upshot of this that a desktop can be kept ticking over longer than an all-in-one; you can replace the bits you need without having to get rid of the whole device.
• Can be cheaper If you already have a monitor and a keyboard and mouse, a desktop PC is better value than an all-in-one. 
• More powerful While the basic specs might not look all that different, larger tower desktop PCs are generally a little faster than all-in-ones. That's because their internal components have more room to expel heat, meaning they can run faster for longer. The components inside of an all-in-one are usually more akin to what you'll find in laptops.

Need a new monitor? See our pick of the best computer monitors

Disadvantages of a desktop PC

• Sometimes bulky Make sure you know the dimensions of the desktop you're buying. Some are big, although most these days are on the small side.
• Separate accessory costs What comes in the box with your desktop depends on where you order it from. Some come with keyboard and mouse, while others will require you to purchase a monitor, speakers, and peripherals separately. While this does grant you the freedom to pick the ones you want, it does lack the convenience of an all-in-one where everything you need is in the box.
• Not as user-friendly While we’ve come a long way since the days of home PCs being the reserve of the technologically minded, if tech daunts you, you might be slightly put off by the concept of a connecting up a desktop or custom-choosing its inner workings, compared to the ‘plug and play’ nature of an all-in-one.

Advantages of an all-in-one PC

• Easy setup There’s very little fuss involved in setting up an all-in-one PC, with most simply requiring you to take it out of the box, place it where you want it, plug it in and turn it on. It’s a good option if you don’t want to be bogged down by cables and you want to get up and running quickly.
• Space saving If space is at a premium, an all-in-one can be a good fit as you'll only need to consider where to place the screen, and don’t have to house a traditional ‘tower’ too. This makes them more flexible in the home, and also a degree more portable. It’s much easier to move an all-in-one from one spot in your home to another. 

Disadvantages of an all-in-one PC

• Flimsy accessories While all-in-ones do come with accessories in the box and built in speakers, our tests tend to reveal that they’re rarely great, and usually rather basic. A desktop PC might allow you to choose the peripherals you would like, but with an all-in-one, you’re stuck with those it comes with, unless you want to shell out and purchase additional accessories.
• More expensive You can end up paying extra for convenience. While there are benefits to picking up an all-in-one, you’re often left paying extra. You could find that an equivalently powered desktop PC is considerably cheaper, even once the monitor and accessories have been taken into account.
• Less powerful As mentioned above, they often use laptop-grade components instead of more powerful desktop-grade ones. This is fine, but if absolute performance is a must, you should opt for a big tower instead.

Desktop computers with DVD drives

Desktop PCs with DVD drives installed aren’t as common as they used to be. But don't let this put you off, because it’s incredibly easy and cheap to buy a USB DVD drive for when you need it. They work exactly like an external USB hard drive, but instead of a hard disk inside there’s whatever CD or DVD you choose. 

A model such as this Asus DVD drive at Argos will set you back around £30.

How to choose accessories

Once you’ve bought your new desktop PC, you’ll need to pick up some accessories, depending on what was included in the box. These will include a keyboard, mouse and speakers, as well as a monitor.

While there are a wide selection of peripherals for all budgets, it’s important to consider your own requirements and not be tempted by flashy products that you won’t make use of. 

How to choose a keyboard

Wired or wireless Most of us tend to use a keyboard in the same position, so it may not matter if you’re tethered by a wire. However, it’s always nice to cut out clutter, so one less wire can help keep your work station tidy. A good wireless keyboard can be more expensive than a wired option, but gives a freedom that you won’t get with a wired one.

Ergonomic keyboards Ergonomic keyboards are designed to feel more natural to type on, and can be a boon if you spend hours at a time typing. They tend to put less stress on the wrists and forearms, helping to cut down on chronic pain and repetitive strain. They take some getting used to, as the button placement is slightly different to a traditional keyboard. If possible, try one out before buying.

UK keyboard Keyboards have different layouts depending on the country they are intended for. This can be as small a change as the placement of the @ symbol, to the ordering of the letters being rearranged. Check that the keyboard is UK standard, especially if you’re buying online.

Media keys For those using their PCs to play music and movies, a keyboard with dedicated media buttons can be extremely convenient. The inclusion of play, pause and volume buttons saves having to navigate to the program with the mouse.

How to choose a PC mouse

Wired or wireless A wireless mouse is arguably more useful if it’s being used with a laptop, but if you want a wire-free work surface, then they can be a great choice for a desktop, too. As the power drain on a wireless mouse is low, you’ll find that the battery life is excellent – one set should last for months. Some models can be recharged over USB instead of having to replace the batteries.

How many buttons Most desktop mouse designs have two buttons and a scroll wheel. However, with the introduction of programmable buttons on more advanced models, there can be huge convenience to being able to add your most used keys to the mouse.

Ergonomic mouse You’ll be using you mouse a lot, so it’s important that it feels comfortable. Ergonomic mouse designs pay special attention to the contours of your hand, with natural button placement. They’re not for everyone, and can feel a bit strange initially, but can be useful for eliminating some conditions, such as RSI.

Left-handed mouse Most computer mouse designs will work with either hand, but this isn’t always the case, especially for specially designed ergonomic models. If you’re left handed, make sure that the one you pick feels comfortable.

Get tech confident for less

Get 12 months of tech support and buying advice for only £34.30, that's a 30% saving. Together we’ll show your tech who’s boss.

Join Which? Tech Support

Offer ends 16 Jun 25. Cancel anytime.

Join our Tech Support service to get expert, unlimited 1-to-1 support as often as you need.