BitLocker disk encryption, which is only available for Windows 11 Pro systems and is often activated by default, can reduce SSD performance by up to 45 percent. Tom’s Hardware states this based on its own testing.

For its results He has tom devices Three scenarios were tested: without BitLocker encryption, with BitLocker software encryption, which is enabled by default in Windows 11 Pro, and with BitLocker hardware encryption. This included looking at write and read speed, and degree of latency. With software encryption of the drive, SSD performance measured in PCMark 10 benchmarks was twenty percent lower on average compared to performance with hardware encryption and no drive encryption. The CrystalDiskMark 8 random read test showed a similar difference in performance, but the software encryption performed 45 percent worse in the random write test.

Significantly lower SSD performance was also measured using the DiskBench and Atto Disk benchmarks. However, in almost all cases, the SSD performed as well with hardware encryption as it did when disk encryption was completely disabled. Testing was conducted using a 4TB Samsung 990 Pro SSD, with an Intel Core i9-12900K processor and 32GB of DDR4 RAM.

Microsoft uses BitLocker software disk encryption by default, after the company decided in 2019 to ignore hardware encryption in Windows and encrypt the disk using software. The tech giant may have chosen this because SSD manufacturers don’t do the security of their drives very well. This would make it possible to bypass disk encryption relatively easily. By performing disk encryption at the software level, Microsoft itself controls security.

However, the processor must decrypt the entire disk and then encrypt it again. Microsoft then stated that modern computers now have enough CPU speed to perform such encryption quickly without making the computer slow, but according to Tom’s Hardware, that doesn’t seem to be quite the case. If users want to set up hardware encryption, they must completely reinstall Windows 11 Pro and use the Rufus tool to ensure software encryption is not automatically reactivated during installation. It is also possible to completely disable disk encryption using Command Prompt.