Compressing Drive Contents Win 10

[Gary1124 181]

Whenever I go to clean up one of my hard drives I see an option to compress files on the drive

Would that render the data unusable until uncompressed or would it just slow data access?

How does that work and is it useful?

Thanks

[stans 702]

It has been so long since I used a disk compression routine that I do not remember all the details.  If I recall correctly, it compresses the data, sort of like when you create a  ZIP file, making it unusable until decompressed.  This saves disk space, which was really important when hard drives were very expensive and had very limited capacity, but it slows read performance because the data must be decompressed.

[Gary1124 181]

24 minutes ago, stans said:

It has been so long since I used a disk compression routine that I do not remember all the details.  If I recall correctly, it compresses the data, sort of like when you create a  ZIP file, making it unusable until decompressed.  This saves disk space, which was really important when hard drives were very expensive and had very limited capacity, but it slows read performance because the data must be decompressed.

That's sort of what I thought. My C drive only 240 and win 10 and FSX-Steam chew most of it. I have to move things to folders on D which is 2tb. 60 something bucks would get me an NVMe 500 gig. Just right for P3d and xplane.

[stans 702]

You would definitely want the OS on the NVMe drive.  You can also put P3D on the NVMe drive, if there is sufficient space, otherwise, put sims and everything else on a SSD.  With SSD and NVMe drives, you do not want them to be more than 75% full, otherwise, performance will suffer.

[Gary1124 181]

19 minutes ago, stans said:

You would definitely want the OS on the NVMe drive.  You can also put P3D on the NVMe drive, if there is sufficient space, otherwise, put sims and everything else on a SSD.  With SSD and NVMe drives, you do not want them to be more than 75% full, otherwise, performance will suffer.

My OS is already on my 240 SSD Drive C. Came that way. Not a new build and I'm not up for major reconfiguring. Thanks

[Luke 782]

On 6/3/2021 at 6:16 AM, stans said:

it slows read performance because the data must be decompressed.

That's true, but it also reduces the amount of I/O that needs to happen. There's probably a point where the reduced I/O overcomes the additional CPU cycles required, but I'm not sure where that is on the spectrum of drive speeds.

On 6/4/2021 at 6:24 AM, stans said:

With SSD and NVMe drives, you do not want them to be more than 75% full, otherwise, performance will suffer.

There's absolutely no effect on read speeds, and if you have a modern O/S that does on-demand and regular scheduled TRIMs, it really won't affect writes until you get a very small amount of free space left.

Cheers!