Các tệp nén NTFS được giải nén vào đĩa hoặc bộ nhớ?

How does NTFS decompression work in Windows? According to Microsoft, NTFS decompression is done by expanding the file, then using it. That sounds right, but my question is how does this process occur technically?

Does Windows load the compressed file into memory, expand it in memory, then read it from memory? Or does it load the compressed file into memory, expand it to disk or memory, write it to disk, then read it?

I am trying to figure out if I can improve my computer’s performance by using NTFS compression. That way, a slow hard drive or SSD that is unable to handle that many write operations will always have less data to write and read, and the powerful processor that is idling most of the time can decompress the files and improve my computer’s storage speed and health.

Windows decompresses files into memory. Doing it to disk would completely obliterate any speed improvements and would cause a lot of unnecessary disk writing. See the end of this Microsoft blog article on NTFS sparse files and compression.

If your SSD is fast, you are probably not going to get any speed improvements from NTFS compression. It is conceivable that the time your processor spends decompressing data plus the time your disk spends reading the compressed data could add up to be more than the time your SSD takes to read the uncompressed data.

It also depends on the size of the files you work with. The minimum size of a compressible file ranges from 8 – 64 KB, depending on your cluster size. Any files less than that in size will not be compressed at all, but a tiny amount of bookkeeping would be added. If you do a lot of writing to compressed files, you could see a lot of variance in speed due to the compression algorithm used (LZ).

Further Reading

How Does NTFS Compression Affect Performance?