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How to Replace the CPU in a Desktop Computer – Complete Guide

How to guide for replacing the processor in a desktop trading computer, gaming computer or home and office computer.

Replacing a CPU in a desktop computer

This guide is for DIY computer enthusiasts that have a desktop computer with a processor (CPU) that needs to be replaced. In this guide, we’ll give a specific example of replacing a desktop processor on an LGA1700 socket (Intel 13th Gen CPU – 13900K, 13900KS, 13700KS, etc). We’ll be showing pictures of an Intel motherboard manufactured by ASUS. But these instructions can apply to any installation of similar Intel hardware with minor adjustments. It’s important to note that installation on an AMD socket is similar, but there are some key differences we’ll also cover.

Definitions of Common Terms

If we are going to discuss technical information it’s important that the reader understands the basic computer terminology involved.

Processor or CPU: The term CPU stands for central processing unit. This is the most vital component in a modern computer. Throughout this article, we’ll use the term CPU and processor interchangeably, they mean the same thing. The CPU is responsible for interpretation and execution of instructions within a computer system. In the context of personal computers (PCs), the CPU typically consists of a single microprocessor.

Often, we hear people refer to a CPU when referring to a circuit board (not necessarily in a computer). While this technically could be correct, we like to think of the term CPU as a single microprocessor made by Intel or AMD. The term “processor” is frequently employed as a synonym for CPU, encompassing the various technologies and architectures that drive computational tasks. It serves as a convenient umbrella term, encapsulating the diverse range of CPUs employed across different computing platforms. From the single microprocessor in a PC to the extensive array of processing devices found in high-performance mainframes.

Motherboard Socket: The socket, located on the motherboard, serves as the designated space for installing a processor. When it comes to Intel processors, the socket is equipped with a pin surface that establishes contact with the CPU.

On the other hand, for AMD processors, a plastic socket with holes for the pins is used. In addition, there exists a securing mechanism that ensures the processor remains firmly in place. The socket plays a crucial role in connecting and facilitating communication between the motherboard and the CPU, while also connecting to the CPU power on the board. Sockets exhibit varying shapes and sizes, depending on the number of pins involved.

The image below shows a typical Intel socket on an ASUS motherboard.

Reasons to Replace a Desktop Processor

There can be a lot of different reasons why someone might want to replace a modern desktop CPU. Upgrading your CPU based solely on its age is rarely necessary. Processors have the potential to last indefinitely, as they do not naturally slow down over time when properly maintained. While there may be some minimal silicon degradation over extended periods, the impact on performance is negligible and probably not even noticeable even after many years of usage.

If you originally purchased a system with cost in mind, you probably didn’t select the best processor that the motherboard and chipset are capable of supporting. By simply upgrading the CPU, you could achieve a significant performance boost of 2% to 5%, or maybe even more! Moreover, opting for a higher-end chip would also provide you with additional cores/threads. Consider the 13700K, which boasts 16 Cores and 24 Threads. Upgrading to the 13900K would elevate your system to 24 Cores and 32 Threads, unlocking even greater processing power.

What CPUs Does Your Motherboard Support

Before delving further into this article, it’s crucial to first determine the processor currently installed in your system and the potential upgrade options that your motherboard can accommodate. It’s possible that you already have the best processor supported by your motherboard. In such a scenario, your only alternatives would be to invest in a completely new computer or, if you are a DIY system builder, to replace the fundamental components of your system, namely the motherboard, CPU, and memory.

In Windows 11, type “About” in the search bar that’s located on the taskbar (right next to the start button). You’ll see your processor name in the device specifications.

If you’re uncertain about the specifics of your motherboard, simply inspect the interior of your computer where you’ll find the name and model of the motherboard printed directly on it. Or you can enter the system BIOS to find out the model of motherboard you have. Once you’ve identified the motherboard model, visit the manufacturer’s website. There, you can search for your motherboard model. Motherboard manufacturers will provide a comprehensive list of compatible CPU and system memory options for your motherboard.

Important Considerations

  • Be careful to avoid bending any pins located on the CPU socket of an Intel motherboard. On an AMD motherboard there are no pins on the motherboard, the pins are on the processor itself, which makes it even more important to be very careful when handling the CPU.
  • Make sure you install the correct CPU type designed for the motherboard socket that you are using. For example, if you have a motherboard with an LGA1700 socket, make sure the CPU is for LGA1700. A quick google search on your processor socket will reveal a full list of compatible processors.
  • The CPU fits into the socket in only one correct orientation. The CPU should never be forced into the socket, it drops in nice and easily and no pressure or direct force is required.
  • Always turn off the computer and unplug the power cord from the power supply.
  • If you have any concerns about potential damage to your computer during the CPU swap process, we strongly advise seeking assistance from a professional. We are not responsible for any damages that may occur from utilizing the information provided in this article. It is important to consider that if your computer is still covered by the manufacturer’s warranty, swapping the CPU could potentially void the warranty, so it might not be advisable in such cases.

In this article we’re not going to cover in detail how to remove or upgrade your CPU cooler beyond the basics of removing the heatsink with a screwdriver. The computer market offers a vast array of CPU air coolers and liquid cooling solutions, making it impractical to cover every option within the scope of this article. It is advisable to refer to the installation instructions specific to your cooler model.

If you’re already experiencing thermal issues with your current CPU cooling solution, upgrading to a faster processor with more cores will likely worsen the problem. This presents an opportune moment to consider investing in a new and improved CPU cooler that can effectively handle the increased demands of the upgraded processor.

Tools You’ll Need

  • #2 Phillips Screwdriver
  • Isopropyl Alcohol
  • New Thermal Paste
  • Microfiber Cloth
  • Anti-Static Wrist Strap

Steps In Replacing the Processor on a Motherboard

We’ll outline the steps below, then cover them in detail one by one throughout the rest of the article. This guide was written for replacing a CPU on an existing system. But the steps also apply to installing a CPU on a brand new motherboard, except for removing the old CPU and cleaning the old thermal paste.

Replacement Steps

  • Preliminary: Check your current motherboard BIOS to make sure that it is compatible with the CPU you want to install.
  • Remove heatsink (air cooler) or waterblock (liquid cooler).
  • Clean off the old thermal paste on the CPU and heatsink base plate or waterblock.
  • Lift the retention arm on the CPU socket on the motherboard.
  • Remove the old processor from the motherboard socket.
  • Install the new processor into the motherboard socket.
  • Apply new thermal paste to the processor.
  • Reinstall the CPU cooler on the new processor.
  • Check temps in the BIOS to verify the CPU is operating at the proper temperature.

If you are installing a new processor on a brand new motherboard, there will be a PNP cap (pick and place cap) on the lid to the motherboard socket. This cap protects the CPU socket from physical damage like bent pins or debris.

Enter the system BIOS and document the BIOS version. Check the manufacturer’s website to make sure the current version you are using is compatible with the new processor. If not, you’ll need to follow the instructions provided by the motherboard manufacturer to upgrade the BIOS.

Step 1: Remove the CPU Cooler Heatsink (air cooler) or Waterblock (liquid cooler)

Every CPU cooling solution has a slightly different method of installation with different mounting hardware. But almost universally we are looking at removing 2 to 4 screws with a phillips screwdriver.

First thing you’ll need to do is unplug the CPU cooling fan from the motherboard. If we are talking about an air cooler there is usually a single fan, but sometimes there can be two fans. Unplug and remove the fans from the heatsink. Then unscrew the heatsink from the motherboard and remove it.

Some coolers, like stock air coolers from Intel won’t require a screwdriver. You twist the 4 plastic push-in clips in the corners to release each one. AMD stock coolers sometimes have retention clips on the sides that need to be released.

If you have a liquid cooler, there will be a waterblock attached to the processor. The most common installation method is 4 screws, one in each corner of the waterblock. All you need to do is remove the screws and the waterblock easily lifts off the CPU.

Pro Tip!

When removing the CPU cooler from an AMD processor, it is important to be very careful! It is common for the thermal paste to adhere firmly, and simply pulling on the heatsink may result in accidentally detaching the CPU from the socket while it remains attached to the base plate on the CPU cooler heatsink. Surprisingly, this happens more frequent than one might expect. You want to remove the heatsink with the processor still in the CPU socket on the motherboard. Intel processors don’t have this problem because there is a load plate locking the CPU down.

Step 2: Clean Off the Old Thermal Paste

With meticulous care, use a microfiber cloth and isopropyl alcohol to thoroughly clean both the CPU and the base plate of the heatsink or waterblock. Ensure that every trace of the previous thermal paste is entirely removed. Since you are replacing the processor with a different one, feel free to clean off the thermal paste on the CPU after it has been removed. If you want to clean the processor after removing it, you can do that after completing step 4.

Step 3: Release the Retention Arm on the CPU Socket

The “retention arm”, or “load lever” locks the processor into the socket. On an Intel motherboard the retention arm pushes down on a metal socket lid called the “load plate” that presses down on the processor. Releasing the retention arm allows the lid to open so you can remove the processor.

On most AMD processors, there isn’t a “load plate”, the processor has pins and plugs directly into the the socket on the board. The retention arm then internally locks the processor into the socket so it can’t be removed.

Step 4: Remove the Old CPU From the Motherboard Socket

On Intel processors, open the load plate. Then, using your fingers, gently remove the processor. An anti-static wrist strap required!

On Intel motherboards, do not touch the pins in the CPU socket! The pins are small and very fragile. On AMD CPUs, be careful not to bend any of the pins that are directly connected to the processor itself.

Step 5: Install the New CPU into the Motherboard Socket

Installation is reverse procedure of removal. But when installing the CPU, you need to pay special attention to one of the corners of the processor. There is a small triangle in the corner. This triangle will matchup with a similar triangle marking in the corner of the socket body. On ASUS motherboards, they usually put a triangle on top of the load plate.

Gently place the CPU into the socket, it’s ok to use your fingers, no tools needed. Remember to wear your anti-static wrist strap. Don’t push down on the processor or try to move it around, if you placed it in the correct orientation, it should fit securely into the socket.

Now rotate the load plate onto the processor (Intel only). Then lock the load lever (retention arm) into place (it clips under a little metal tab). Sometimes it feels like it’s really putting a lot of pressure when you are locking it in place with the load lever, that’s ok.

With AMD processors you’ll just use the load lever (retention arm) to lock the CPU into place. When installing the processor into the socket make sure the retention arm is in the “released” position (all the way up) so that the CPU can fit into the socket easily.

Step 6: Apply New Thermal Paste to the CPU

We have written an entire article on thermal paste: How to Apply CPU Thermal Paste to an Intel or AMD Processor.

The amount and application pattern of thermal paste depend on the processor, CPU cooler, and thermal paste itself. While it is not possible to cover all scenarios, a general guideline is to apply a pea-sized dot in the center of the processor. However, with larger, newer CPUs, many coolers require a 5-dot pattern. It is important to refer to the documentation provided by the CPU cooling solution and thermal paste manufacturer for specific instructions.

Avoid solely relying on the images below as the amount of paste needed may vary. Consult the documentation that came with your CPU cooling solution, they will tell you how much thermal paste to use. Excessive paste should be avoided to prevent spillage over the edges of the CPU and into the socket. Insufficient paste may result in high CPU temperatures. Do not spread the thermal paste on top of the processor. The heatsink or waterblock will spread the dots of thermal paste.

This first image shows a 5 dot pattern on an LGA1700 motherboard CPU.

Step 7: Reinstall the CPU Cooler

This will be the reverse of step one. Be careful not to slide the heatsink or waterblock around a lot when installing it. Set it on the CPU and thermal paste, then tighten down each screw. Gradually tighten the thumbscrews in an alternating manner, employing a back and forth pattern. It is crucial to avoid fully tightening one side before commencing with the other, proceeding gradually instead.

Step 8: Check CPU Temps in the BIOS

It’s probably a good idea to verify the CPU temps are within range, while at idle and while at load. This will help you verify that the CPU cooler has been installed correctly.

Temps can vary wildly depending on the type of cooler you have installed. Large 360mm AIO liquid coolers will keep temps more stable and consistently lower, even at idle. Noctua coolers do a very good job also at maintaining appropriate temps. When it comes to stock coolers provided by AMD and Intel, it is worth considering alternative options as they tend to offer subpar cooling performance. We highly recommend replacing them with more efficient cooling solutions.

What is the BIOS?

BIOS stands for Basic Input-Output System, which refers to the essential software stored on a chip within your computer’s motherboard. Upon startup, the BIOS is activated and takes charge of initializing your hardware components, verifying their proper functioning, and subsequently launching the bootloader to boot your operating system.

The BIOS allows you to change any of the computer hardware settings. Exercise caution when accessing the BIOS and refrain from modifying any settings unless you possess a clear understanding of their implications. Altering settings without sufficient knowledge may result in system overheating or damage, which would not be covered under the manufacturer’s warranty. It is essential to approach any changes in the BIOS with utmost care to avoid unintended consequences that could compromise the system’s stability and functionality.

CPU Idle Temp

CPU temperatures can vary significantly, so we won’t be focusing on a specific temperature target. Instead, what you should aim for is to ensure that the CPU temperature remains within reasonable limits, particularly during idle. If you notice a excessively high temperature, such as 70°C, it suggests that something went awry during the reinstallation of the CPU cooler. Possible causes could include inadequate application of thermal paste or insufficiently securing the heatsink or waterblock.

Below is a typical BIOS screen on an ASUS motherboard. This is what a modern UEFI BIOS looks like. This is the first screen you are greeted with when entering the BIOS. It’s called EZ Mode and it gives a quick breakdown of the most important things in the BIOS such as:

  • The time and date settings.
  • The exact processor model.
  • The target speed.
  • The memory amount and speed.
  • DRAM status, what is populated in each of the 4 memory slots.
  • The fan profile overview which shows the status of all the fan ports on the motherboard. Here you can see if you plugged the CPU fan back in properly and see what RPM it’s spinning at.
  • The top/middle of the screen shows the CPU temperature. You can see we’re hovering around 38c on an Intel Core i9 13900k. This is a pretty typical temp at idle on an air cooler, totally normal and within specs.

Motherboard Won’t Post

What happens if the motherboard doesn’t boot up and successfully post? It’s possible you receive a bad CPU, but that is exceedingly rare.

Did you unintentionally bend any pins on the CPU socket during installation? If not, and you followed all the steps flawlessly, why is the computer unable to boot?

As mentioned at the beginning of the article, before you install the new CPU you should enter the BIOS and take note of the BIOS version number. The computer BIOS often requires a firmware update for compatibility with hardware that comes out after the motherboard was designed and manufactured. Good manufacturers like ASUS consistently come out with new and improved BIOS updates to address any issues with hardware compatibility.

Verify on the manufacturer’s website whether the current version you have is compatible with the new processor. If it is not compatible, you will need to refer to the instructions provided by the motherboard manufacturer to update the BIOS accordingly.

Final Thoughts

This concise guide provides step-by-step instructions for replacing a desktop CPU, demonstrating the correct procedure to seamlessly replace an old processor with a new one. We have outlined eight comprehensive steps to help you successfully accomplish this task.

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