Does BitLocker affect the performance of SSDs?

Using BitLocker encryption does indeed decrease the performance of some SSDs, and the degree of impact varies from different version of SSDs. However, once you disable BitLocker, the SSD performance can return to normal.

Actual Test Data about BitLocker Performance Impact on SSD

Here is a comparison of read and write performance data for an SSD with BitLocker enabled and disabled, using CrystalDiskMark with the XTS-AES 128-bit encryption algorithm:

Video test on BitLocker Impact on SSD Read and Write Performance:

The Total Same Group Environment:

The comparison results are as shown in the following chart:

It can be observed that the overall read and write performance of the unencrypted SSD is higher than that of the SSD encrypted with XTS-AES 128-bit.

Interestingly, the encrypted C drive shows significantly higher speeds in 32 queue 4K random read and write compared to when it is unencrypted.

How BitLocker influence SSDs’ performance?

TomsHardware conducted a study last year and found that enabling BitLocker encryption slows down Samsung 990 Pro SSDs up to a staggering 45%. This indicates that SSD locked with BitLocker has a significant reduce on the random read and write performance.

The primary reason is that enabling BitLocker encryption adds an encryption process during file writing to the hard drive, which is heavily influenced by CPU and algorithms. This can result in varying degrees of slowdown in SSD write speed.

Additionally, when continuously reading encrypted content from the SSD, the CPU may need to sustainably decrypt data, leading to slightly higher CPU usage than usual.

How to fix it?

1. Disable BitLocker Encryption

If you do not need to encrypt the data on your computer’s drive, you can choose to disable BitLocker to reduce its performance impact. Refer to "Use cmd to configure BitLocker on Windows System" and use the following command to disable BitLocker (replace the letter "c" with the BitLocker-encrypted drive letter):

2. Switch to Hardware Encryption

Windows system use software BitLocker in default. However, BitLocker also supports Self-Encrypting Drives (SED) or SED-FIPS, which have almost no impact on performance. However, this feature is not enabled by default and requires changes in Group Policy. This operation will be a bit complicated and needs to be chosen cautiously.

Conclusions

It’s important to carefully consider both security and performance when enabling BitLocker on SSDs. However, I still recommend keeping BitLocker enabled to help you prevent malicious intrusions and protect your data.

In general, actually in most cases, uses are unlikely to notice any perceptible difference in performance when BitLocker is enabled on an SSD. So comprehensively consider all factors first and then decide whether to activate BitLocker on your PC.

Tips: iSunshare BitLocker Genius for Windows helps us better handle the BitLocker through straightforward graphical user interface.