No one likes their PC running below its potential, and certainly not without them realizing it. However, that's exactly what might be happening inside countless PCs right now. From basic mistakes like installing memory or storage drives in the wrong slots and ignoring BIOS tweaks to more advanced stuff like ensuring proper contact between the CPU cooler and the CPU's IHS, you might be hurting your PC's performance unknowingly.

Installing RAM in the wrong slots

Might not be obvious to some people

It might feel childishly simple to many users, but choosing the right RAM slots when installing more than one module can be a source of error. Most people use two RAM sticks on their PC, and installing them in the correct slots to take advantage of dual-channel configuration is a must. Otherwise, you're leaving performance on the table for no good reason. Putting two DIMMs in consecutive slots (whether 1 & 2, 2 & 3, or 3 & 4) will force the memory to run in single-channel mode.

The slots 1 & 3 from the left (CPU side), or A1 and B1, and 2 & 4, or A2 and B2, are configured for either channels, and you can plug your modules into any of these configurations to leverage dual-channel benefits. The reason it's advised to populate slots 2 and 4 first (A2 and B2) is to avoid any interference from the CPU cooler, and also because many motherboards won't boot if you use slots 1 and 3. For those using four DIMMs, it doesn't matter, since all four slots need to be populated anyway.

Insufficient contact between the cooler and CPU

It can happen to anyone

When you're building a new PC, mounting the CPU cooler might seem simple, but it's possible to install it suboptimally, where the cooler's heatsink doesn't sit flush with the CPU's IHS. You won't notice this visually, but it will show up in elevated CPU temperatures even in idle conditions. On some systems, this could even lead to extremely high temperatures where the system shuts down to prevent damage to the CPU.

While you can be careful during the installation process to ensure sufficient pressure on the IHS, some CPUs just don't work well with certain coolers. They might need the help of specialized mounting brackets to improve the contact between the heatsink and the IHS. In most cases, however, you can fix the issue by reseating the CPU cooler after ensuring sufficient pressure when securing the screws. Proper contact will ensure optimal heat dissipation, avoid thermal throttling, and allow your CPU to boost higher for longer.

Sticking with the default fan curves

If only that were possible

If you've just set up your new PC, you might notice your fans ramping up unnecessarily whenever you launch any remotely intensive program. This is because of the default fan curves on your system, which are often far from ideal. In most cases, they're too aggressive and make the PC noisier than it needs to be, while in others, they're overtuned for silence, failing to keep temperatures in check. You should always set custom fan curves in the BIOS or a program like Fan Control.

Customizing the fan curves for your CPU, GPU, and system fans allows you granular control over their behavior. You can strike the perfect balance between performance and noise levels, thereby achieving fan speeds suited to your individual needs. The default fan curves will rarely be ideal, hence tuning them is one of the most important things you should do when setting up a new build.

Using the wrong power plan

A silent performance killer

The wrong Windows power plan might be holding your PC back from its potential. On desktops, you should always select the High Performance or Ultimate Performance power plan to prevent Windows from throttling performance in the name of power efficiency. On laptops, things are different, and users can switch between High Performance and Balanced plans, depending on their immediate needs.

If you've never checked out this setting, you might unknowingly be running your PC several notches below its maximum power. Before checking the hardware of your PC for possible performance killers, ensure you haven't selected the wrong power plan in the OS itself.

Using unoptimized BIOS settings

A strict no-no

From forgetting to enable XMP/EXPO for your RAM to ignoring Resizable BAR (ReBAR), there are many BIOS/UEFI mistakes that can tank your PC's performance. While most people might know that the RAM doesn't run at its maximum speed by default, fewer people would know about ReBAR, Precision Boost Overdrive (PBO), or Secure Boot. ReBAR allows your CPU to access your GPU's entire VRAM in one go instead of in small chunks, significantly improving performance.

PBO and Curve Optimizer on AMD CPUs can allow you to get the most out of your CPU while also running it a few degrees cooler without reducing performance. And Secure Boot prevents unsanctioned software from compromising the security of the system during the boot process. There are many other CPU, memory, and storage settings you can tweak in the BIOS/UEFI to optimize your PC, but the ones I listed here should be on everyone's list.

Get rid of silent performance killers

Crippling your PC's performance due to unknown variables is the worst feeling for a PC user. Once you know what mistakes you might have made, you can start fixing them to bring your PC back to maximum performance. Ensuring the right BIOS/UEFI settings, using custom fan curves, and ensuring maximum contact between the CPU and the cooler are some of the most effective ways to ensure your PC is running as it should.