Bug Report Windows Hard Drive Compression causes recordings to drop frames.

[aweblade4]

Incase you are wondering what I mean by hard drive compression this is what I mean.

This bug effects OBS studio and OBS classic, I use classic to record and I have been for years. I am recording via game capture. I've tried this on all my hard drives and only the drive without compression enabled doesn't throw high cpu encoding errors and/or dropping frames. The framerate drops from 60fps to the 50s. OBS Studio wont even show the issue in the interface. It happens more often when the framerate is uncapped. I'm also using Nvidia's Studio Driver not the game ready driver. I need the studio driver for davinci resolve my editing software of choice. I'm using windows 10 build 18363 I didn't have this problem 2 update prior.

OBS Studio Log
OBS Classic Log

 

[Harold]

It's not a bug actually. It's a property of doing on the fly compression of data.
Don't use compression on folder you're saving your videos to. Videos coming out of OBS are already compressed.

 

[aweblade4]

I didn't have this problem before so....

 

[koala]

Enabling compression globally for a complete drive makes Windows compress every file on that drive. This causes massive fragmentation of the harddisk as well (I can explain why, if you don't believe it).

If the disk gets full, and less than 10% full as in your screenhot is "getting full", files are filled in the fragmented free space of the drive, causing even more fragmentation. In the end, Windows has to seek to a different sector and track for about every file cluster due to fragmentation, which increases the write latency massively and decrease read and write speed massively. This latency causes frame drops if OBS writes to such a drive, and this is what happens for you. First, you had more disk space, so you had not so bad fragmentation. Now with more and more files written to, the fragmentation increased and read/write speed is down.

tl;dr:
Don't use compression for a whole drive. Ever.
If you have disk space issues, remove unused files.
If you don't have unused files, buy an additional hard disk.
If you cannot add an additional hard disk, as last resort (and really last resort) you may search for single directories that contain files that are rarely accessed and never written to. And which can be compressed with a good compression ratio. Enable compression for these directories only, but not for the whole drive. Video files are very bad candidates for file system compression, because they already contain compressed data that cannot be compressed again.

What you should do:
Disable compression for the drive. Decompress every directory and every file except directories I described above.
After decompression, run defrag. It may be that it isn't able to do its job due to massive fragmentation. In this case you have to remove files until defrag has enough space to do its job.

 

[aweblade4]

If the disk gets full, and less than 10% full as in your screenhot is "getting full", files are filled in the fragmented free space of the drive, causing even more fragmentation. In the end, Windows has to seek to a different sector and track for about every file cluster due to fragmentation, which increases the write latency massively and decrease read and write speed massively. This latency causes frame drops if OBS writes to such a drive, and this is what happens for you. First, you had more disk space, so you had not so bad fragmentation. Now with more and more files written to, the fragmentation increased and read/write speed is down.

I've had alot less space on that drive and it still was able to perform normally. Also windows 10 defrags hard drives automatically. I've defragged that drive manually to see if that would fix it, but it didn't. I just think microsoft did something to compression and a patch needs to be released. OBS is the only recording software that has this issue. Shadowplay also does not have this issue when recording to the same drive (I just tested this). So the issue is either with the recent windows update or OBS.

 

[koala]

If you value your time, you see a value equivalent to money in it. The older you get, the more you will understand this. Then, wasting your time with ntfs compression is more expensive than buying an additional storage device. So don't waste your time with file compression (which is equivalent to wasting money) and buy a new storage device instead. It's cheaper than your precious time and you get a real benefit.

 

[aweblade4]

If you value your time, you see a value equivalent to money in it. The older you get, the more you will understand this. Then, wasting your time with ntfs compression is more expensive than buying an additional storage device. So don't waste your time with file compression (which is equivalent to wasting money) and buy a new storage device instead. It's cheaper than your precious time and you get a real benefit.

I'm not looking for help, I'm just reporting a bug. Compressing the drive means I can use the drive for longer without deleting or moving files. So your point is moot.

 

[Narcogen]

That's not a bug.

 

[aweblade4]

That's not a bug.

If it's not a bug than what is it. Something is clearly off that happened recently and my hard drives have been compressed for years. This issue only occured in the last 3 days.

Edit: also the log reported a memory leak and this issue only happens with OBS. Other recording software don't do this when recording to the same drives.