6 BIOS settings I always change on a new PC — most people skip all of them

You’ve finally built your new PC — congratulations. Unfortunately, when you boot it up and run benchmarks and video games, you don’t get the same performance as advertised or as seen in online benchmarks. Now you might think it’s a hardware flaw, and trust me, with nearly 15 years of experience building PCs, it’s most likely not. From what I’ve garnered over the years, this is more of an issue where your PC components aren’t running to their fullest potential because of some settings hidden deep in the BIOS menu.

As such, I’ve created an entire checklist of settings to enable in the BIOS menu for whenever I assemble a new PC. Turning them on will ensure your PC is running to its fullest potential, and I highly recommend going through this list.

Your RAM is sandbagging itself by default

You paid for higher speeds, but your PC doesn’t get the memo unless specifically told

One of the most common issues that PC owners face is their RAM not running at full speed. Now, you may have bought yourselves DDR5 RAM advertised to run at 6000MT/s, but in reality, it is most probably running at a much lower speed. The standard for DDR5 RAM is 4800MT/s, and most kits run at that speed even if they’re capable of more.

The advertised speed is with the overclocked profile — though not in the traditional sense, since it’s been safely tested by the manufacturer, is completely harmless to turn on, and doesn’t void your warranty. To reach the advertised speed, you have to follow these steps:

1. Enter BIOS on startup by either pressing F2 or the Delete key.
2. Depending on your motherboard, navigate to either Overclocking/AI Tweaker/Tweaker/Advanced Memory Settings.
3. You’ll have to find either of these settings: XMP for Intel chipsets or EXPO/A-XMP for AMD chipsets, enable it, and your RAM will now be able to work at its advertised speeds.

PCIe lane congestion can hold your GPU back

Utilizing too many slots can backfire

Modern motherboards come with several PCIe slots, but sometimes these extra slots can slow down your PC. No matter how many PCIe slots your motherboard has, your CPU still ends up being a bottleneck because it only has a fixed number of usable lanes. When there are too many devices on your motherboard, the bandwidth gets congested, and your devices have to resort to lower speeds, i.e., the GPU. You can check whether your GPU’s speed is being limited by opening GPU-Z and matching the figures in the bandwidth section.

In case it’s being limited, unlock full speed for your GPU by entering BIOS -> PCI subsystem settings, and there you’ll find your GPU in the said PCIe slot. Check which speed it’s running at and crank it to the max level, even when it’s set to Auto, if the GPU-Z figures don’t match.

By default, fans play it too safe for my liking

Crank up those fan speeds

Summers are the worst time to be a PC owner. I’ve spent many thousands of dollars on my setup, and I have to be extra careful when monitoring temperatures. My system runs extra hot, and even though I’ve done my best to ensure optimal cooling for my PC, it still doesn’t keep the temperatures in check because of how hot summers get.

Fortunately, my PC can run cooler, but unfortunately, it doesn’t want to. All the fans on my system are programmed by default to prioritize longevity over maximum performance. Running hot will degrade your main hardware, so I’d rather let my fans wear out rather than the GPU and the CPU. If you live in a hot area like me or just want to ensure extra cooling for your PC, adjusting your PC’s fan curve requires a different walkthrough for different motherboard brands.

In the BIOS, it’s under Hardware Monitor -> Q-Fan Control (ASUS)-> Smart Fan -> Fan Tuning.

MSI calls it Fan Control under Hardware Monitor, Gigabyte calls it Smart Fan 6, and ASRock uses FAN-Tastic Tuning as the naming convention.

From there, you can set up your fan curves for intake, exhaust, and CPU fans, and adjust their speeds for a given temperature threshold. Here are the speeds I personally use for all fans for reference, but you can adjust them depending on your temperature. Do keep in mind that they will make your PC loud.

C-state kills your gaming performance

Wake up your CPU completely

Now, this is an interesting one. C-states are power states for your CPU designed for power saving and represent the state your CPU is in. Ideally, they make your PC quieter and more power-efficient, but they can sometimes throttle performance and cause latency. My goal is always to achieve peak performance from my PC, which is why I disable C-state in every new setup that I assemble.

Under your BIOS settings, go to either Advanced or CPU configuration. From there, you’ll come across settings labeled Package C State Limit for Intel chipsets and Global C-State Control/CPU C States for AMD CPU owners. Click that setting and change it to disabled from Auto/Enabled.

Just in my last build for a friend, turning off C-state vastly improved gaming performance, effectively eliminating those random FPS drops and spikes in CPU-bound games, smoothing the low 1%.

Resizable Bar Support is a free performance upgrade

Your GPU’s waiting for you to toggle this option

By default, your CPU accesses your VRAM in 256 MB chunks, which is too little for modern AAA games and heavy workloads. Fortunately, Resizable Bar Support removes that restriction by allowing access to all of your GPU’s memory at once. The result is reduced asset loading times in games and much better FPS. Also, if you have a slightly older CPU, this setting can also reduce the bottleneck slightly by taking off the load. In fact, Nvidia’s testing showed that enabling Resizable Bar Support could result in a whopping performance increase of up to 15%. To enable Resizable Bar Support, you have to turn on Above 4G Decoding first, and you can enable these settings by following these steps:

1. Enter BIOS via F2/Delete.
2. Navigate to PCIe Settings.
3. Enable Above 4G Decoding.
4. Resizable Bar will appear only afterward for some motherboards; enable it then.

PBO/MCE lets your CPU push further and beyond

Your CPU is capable of more than you think

If you want the maximum speed from your CPU without overclocking, this one CPU BIOS setting will help you unlock extra FPS in those CPU-bound games and render faster on workloads. For AMD, the feature is called PBO (Precision Boost Overdrive), and for Intel, it’s called MCE (Multi-Core Enhancement).

Essentially, this setting gives your CPU more headroom to sustain and reach its boost speed. Typically, your CPU boosts within its rated limit, but PBO/MCE gives it more headroom to push beyond the ceiling by drawing more power. In a nutshell, think of it as a race mode for a car.

While PBO and MCE are safe to enable, they will increase power draw, which will make your CPU run hotter than usual. Therefore, I recommend enabling this setting only if your system has adequate cooling.

In your BIOS menu, you’ll find PBO/MCE under Advanced System Settings or Advanced CPU configuration. For Intel, MCE will be labeled MCE/Enhanced Turbo/Enhanced Multi-Core Performance.

Your PC was holding back — not anymore

For the average PC owner, the BIOS menu may look daunting and rightfully so, since messing it up renders your system useless. However, there are a lot of useful settings and features hidden there that most people tend to ignore and overlook, but enabling them would give you a meaningful performance gain. These settings and features don’t override your hardware’s base profiles in ways that would void the warranty and are completely safe to enable/disable, as long as you follow the steps above. Notably, the steps to turn on these features might be different based on your motherboard’s brand and which CPU you’re rocking, or on some hardware, they might not be supported at all.