I recently switched to a WD Black M.2 SSD as the primary drive on my gaming PC. I was using an HDD earlier, so, of course, I expected a lot of performance gains and faster load times on my video games. That happened. However, I began noticing delays and brief stutters in daily usage, as well as random freezes when launching video games. It wasn’t constant, but enough to make me look deeper and figure out why it was happening. The culprit behind the stutters was a power setting that resulted in the SSD napping on the job, or more accurately, napping in-between jobs,

A Windows power-saving feature is the culprit

With great power saving comes great latency

Over the years, it’s become tricky to find a sweet spot between battery life and performance on Windows PCs. It’s because Microsoft has aggressively dialed up Windows’ power-saving features. While this has its advantages: you spend less on electricity, and laptops have better battery life, it does cause performance issues that discerning users will easily notice. By performance issues, I don’t mean it’s actively slowing your PC; it’s just that its components tend to go into power-saving mode more easily. Switching your power plan to High Performance does help, but some settings still remain unaffected.

Since NVMe SSDs use the PCIe interface to connect to your motherboard, the power setting that you should pay attention to is, PCIe Link State Power Management. You can find it in Control Panel -> Power Options -> Change Plan Settings next to your selected power plan. Expand the PCI Express tree in the advanced power settings window, and you’ll see Link State Power Management is further divided into Plugged in and On battery. If you’re on a desktop computer like me, set both options to Off using the drop-down menus. On laptops, it’s best to leave the setting at Moderate Power Savings.

The PCIe Link State Power Management setting is the Windows-facing control for PCIe ASPM (Active State Power Management), a power management protocol built into the PCIe specification itself. If changing the Link State Power Management setting doesn’t make any difference, you may need to disable ASPM by going to the BIOS settings. Keep in mind that this is more of an absolute off switch that works at the firmware level. Some motherboards let you pick among multiple options:

1. Disabled/L0 (ASPM OFF)
2. L0s (Lightest power-saving state)
3. L1 (Deep power-saving state)
4. L0sL1 (Both power states active, the system picks one depending on idle duration
5. Auto

The BIOS basically provides you more granular control over the power-saving states. The Link State Power Options in Windows’ advanced power settings window roughly correspond to: Off (L0, no power saving), Moderate power savings (L0s), Maximum power savings (L1 and deeper substates).

There’s another setting worth looking at

Especially if you’re using a laptop

I don’t suggest setting the PCIe Link State Power Management setting to Off on laptops, as it adversely affects the battery life. Instead, try increasing the NVMe Idle Timeout value. This value determines how soon the SSD transitions to a low-power state when it’s idle. The default value is usually 100 milliseconds on battery and 200 milliseconds when plugged in, on the Balanced power plan.

The NVMe Idle Timeout setting is not visible in Windows by default. To enable it, run the following commands in an elevated instance of Command Prompt:

• REG ADD HKLM\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\0012ee47-9041-4b5d-9b77-535fba8b1442\d639518a-e56d-4345-8af2-b9f32fb26109 /v Attributes /t REG_DWORD /d 2 /f
• powercfg -attributes SUB_DISK d639518a-e56d-4345-8af2-b9f32fb26109 -ATTRIB_HIDE

Once you execute these commands, the NVMe Idle Timeout setting should appear in the Hard disk tree in the Change advanced power settings window. Set higher values so that the SSD doesn’t go into power-saving states too quickly. In case you don’t want the SSD to go into idle state at all, set the value to 0.

On some computers, the setting may not show up even after executing the commands listed above. Some NVMe controllers and drivers (especially on Windows 11) don’t support it, so there’s really not much you can do about it. In my case, I couldn’t get the setting to show up on my Surface Laptop 3, but it showed up instantly on my desktop computer.

Changing power settings won’t magically improve your SSD’s performance

The lag and stutters I noticed on my PC were caused by latency spikes when the SSD woke up from a power-saving state. This doesn’t mean that it was consistently performing at a lower speed. Disabling PCIe Link State Power Management or increasing the NVMe Idle Timeout value won’t magically increase your SSD’s overall performance; it will just make it more responsive.