How to Upgrade a CPU

This article explains how to upgrade a processor properly, with clear, step-by-step instructions.

Should You Upgrade a CPU Yourself?

Learning how to upgrade a CPU is a right of passage for any DIY PC enthusiast. It's not overly complex, but you need to execute it carefully, as there is real potential to damage your CPU and your motherboard. Even if you do it mostly right, leaving components with inadequate cooling can lead to overheating and further damage.

Before You Buy a New CPU

The first step in any CPU upgrade journey is buying the right one. If you're starting from scratch with a brand new PC and are looking to upgrade the entire system in one go, then a great place to start is with our AMD vs. Intel guide. Picking one camp over the other will lead you down the path of bespoke motherboards and exclusive features, even if both camps offer excellent processors for a variety of budgets, whether you're replacing a CPU for gaming, work, or a little of both.

When you've decided on the brand you're targeting, look at our buying guide below to help you pick the right CPU for you.

Make sure to pick a CPU that is compatible with your motherboard. Don't spend too much, either, as there are diminishing returns after a certain point unless you're building the most high-end gaming PCs or the most powerful video transcoding machines. Even then, the top chips can be inordinately expensive. A focus on more significant components (like the graphics card for gaming) can be of more importance, depending on what you want to do with your PC.

What You'll Need For a CPU Upgrade

Along with the CPU itself, there are also a few tools and items you'll need to complete a successful CPU upgrade:

• An anti-static wrist strap: This helps to ground you while you're performing the upgrade and ensures that no static electricity damages your new processor or any of your other PC components.
• A CPU cooler: This may come with your existing CPU or the new one you buy. Not all processors come with one, so make sure to buy a CPU cooler that will work with your cooling and noise level demands. Make sure it fits your CPU socket of choice, although most modern coolers will fit most modern CPUs from both AMD and Intel.

• A good quality heat paste (also called thermal paste): Coolers and the integrated heat spreader (IHS) used on modern processors are relatively flat and smooth. But there are grooves and rivulets at the microscopic level that create an imperfect surface for heat transfer. That's where a high-quality heat paste can come in. It fills the gaps and ensures the maximum amount of heat is transmitted away from your processor.
• A lint-free cloth and 99% isopropyl alcohol: This removes old heat paste and is necessary if you plan to re-use your existing cooler.
• A Phillips screwdriver: Most coolers require some screws to hold the heatsink and sometimes its fan(s) in place. Most often, they use Phillips head screws. A long screwdriver can simplify the process.

Preparing to Replace a CPU

Before you get started replacing your CPU, back up any important data on your PC. This step guarantees you won't lose anything valuable if you need to format your hard drive when changing PC components.

You also want to prepare your CPU upgrade surface effectively, making sure it's clear of dust, dirt, and debris. Make sure it's not a conductive surface like metal, nor a carpeted floor. A wooden or ceramic desk surface is ideal. If you are standing on a carpeted surface, it's recommendable to wear rubber-soled shoes as a secondary protection against static discharge.

Doing so in a well-lit area or supplementing overhead lights with a desk or headlamp can also make the process much easier.

How to Replace a CPU

When you finish prepping, remove all the cables from your PC and take off its side panel, attach your anti-static wrist band, and make sure you have all your tools and components ready.

1. Remove the original CPU cooler. If it's the stock Intel/AMD CPU cooler, this will involve unscrewing the four corner screws. For other coolers, you may need to refer to the manufacturer's manual. If you plan to reuse it, remove the old heat paste using a lint-free cloth and 99% isopropyl alcohol.

   

2. Lift the retention arm that holds the CPU in place. This should require light pressure but will come up easily.

   

3. Carefully remove the old CPU, holding it by the edges and avoiding touching the pins/contacts on the underside. Place it somewhere supportive and non-conductive.

4. Take the new CPU and look for a small, golden triangle in the corner of its top side. Line that up with the arrow on the CPU socket and install the CPU, making sure not to touch the underside pins or contacts. Gently nudge it back and forth once to ensure that it is safely deposited correctly into the socket.

   

5. Press down on the retaining arm to lock the CPU in place.

6. If your CPU cooler does not have pre-applied heat paste, add a pea-sized amount to the CPU's center.

   It might not look like much, but when the cooler is attached, it will spread out, looking something like this:

   

7. Using the mounting instructions for your new or existing CPU cooler, place it gently on top of your CPU. If it uses multiple screws to fix it in place, partially screw them in, starting with screws on the opposite side of one another. For a four-screw cooler, you could start in one corner, then do the one diagonally opposite before screwing in the others. Screw them in a few turns at a time until all are hard to turn. It should not require extreme force. Be wary of overtightening.

   

8. Find the 3 or 4 pin fan header on your motherboard, often designated CPU_FAN, and attach the fan cable to it.

   

Before replacing your PC's side-panel, we recommend that you plug in only the bare necessary cables—power, monitor, keyboard, and mouse—and attempt to power it on. If it boots up, congratulations, you have successfully replaced your CPU and can shut it down, close the case and tidy everything away.

If not, you should retrace your steps to make sure you completed everything successfully.