Any useful scenario for NTFS compression?

Good day.

I know storage space is dirty cheap these days but I am wondering if there is any weird scenario for NTFS compression to be used. For instance, for those very slow hard disks , where throughput is very bad. I am thinking about some netbook/laptop slow 5400rps hard disks and such other configurations where the chipset isn't delivering a good throughput data experience (I am looking at one of my work computers, with a crappy nForce chipset where its IDE hard disk isn't a good performer).

As NTFS compression incurs in small speed penalties and there is no reason to compress either not compressible or writeable data, I am thinking in compressing the Program Files folders only and also those folders which are read often but seldom written to.

Let's hear your insights...

I made a test on my i7 SATA II drive.
Using Apptimer to measure application launch time I NTFS compressed Mozilla Firefox folder and it ran slightly faster when compressed (4,7s vs 5.0).

I defragmented the folder and rebooted the pc before any iteration of the test.

On a slower machine (w7, Phenom 1), MS Office 2010 x64 went unfortunately from 2,56s to 3,41s loading time.
I think NTFS compression Cons overweight the Pros, that is, you incur in some cpu penalty hits and you suffer from terrible fragmentation when writing/modifying. And don't you ever do this on an SSD drive. You will wear out the drive and shorten its lifespam.

eLPuSHeR said:

And don't you ever do this on an SSD drive. You will wear out the drive and shorten its lifespam.

Actually Windows 10 automatically uses compression for OS files if you have a SSD and it determines your CPU is fast enough. You can check it with compact /compactOs:query from the command prompt. It uses xpress4k not NTFS compression though. I always use it as I'm short on space - whether it is faster or slower depends on relative speeds of your IO and CPU - I can't say I've noticed a difference either way on my hardware (i5 + SATA3 SSD).

I also use it on VMs that I keep on USB3 5200 HDD as I figure that the IO will be so slow that even with decompression overhead it will be faster (but again I can't tell any difference).

Note I've been using xpress16k compression not NTFS when compressing non-OS directories ("C:\Program Files" etc)

The purpose of NTFS compression has always been to save disk space, not improve performance, although that may occur under in some situations. Hard drives have greatly increased in capacity in recent years but people have no more difficultly in filling 4 TB drives then they did with 4 GB drives when they became popular. NTFS compression will buy a little time before a drive becomes too small and needs to be replaced.

halasz said:

Actually Windows 10 automatically uses compression for OS files if you have a SSD and it determines your CPU is fast enough. You can check it with compact /compactOs:query from the command prompt. It uses xpress4k not NTFS compression though. I always use it as I'm short on space - whether it is faster or slower depends on relative speeds of your IO and CPU - I can't say I've noticed a difference either way on my hardware (i5 + SATA3 SSD).

I also use it on VMs that I keep on USB3 5200 HDD as I figure that the IO will be so slow that even with decompression overhead it will be faster (but again I can't tell any difference).

Note I've been using xpress16k compression not NTFS when compressing non-OS directories ("C:\Program Files" etc)

I wasn't aware of the compact thing. I ran your command line and it said my system isn't compacted because Windows has determined is not good for my system.

How can I force it for testing purposes? I answer myself: compact /?

compact /compactos:always - see Compact OS - Compress or Uncompress Windows 10 - Windows 10 Forums

It is worth a try - you can always turn it off again.

Yes. I have been doing some tests.

Compacting static executables (Program Files for instance) with the /EXE:LZX switch you gain a lot of space, 3GB or so. Everything gets packed almost 50%. You get a penalty hit when loading, but not very noticeable if you have a beefy cpu. So if you are being low on free disk space you can make some room with this. The main drawback is that as soon you write that data over (by updating any software for instance) the data gets written in uncompressed form. You have to do the packing again. Annoying.

I also tried forcing compacting the os binaries and it yielded about 3GB+ of free space. But you incur in a bigger performance hit here. On a traditional hd OS loading time is almost twice the time.

Anyway a good tool for keeping very static software in a compact manner.

For instance, Crap Cleaner 5.09 x64 goes from 18.005.864 to 6.762.496 bytes. Not bad. Not bad at all...

eLPuSHeR said:

The main drawback is that as soon you write that data over (by updating any software for instance) the data gets written in uncompressed form. You have to do the packing again. Annoying.

It is. The default compression used by windows is xpress4k. I compress folders using /exe:xpress16k (lzx didn't make much difference for me) but as you say new items are not compressed as it doesn't persist if you use /exe:

What I have done as a workaround is this:

compact /c /s /a /f /q /i /exe:xpress16k - the /f switch forces re-compression but /exe: doesn't persist.

and then
compact /c /s /a /q /i - this doesn't have the /f so will not do anything as you have already compressed the directory but will mark it to compress any new items at the default (xpress4k).

Be careful compressing C:\Windows directories, especially those in C:\Windows\System32 using other than NTFS as Windows will not boot if you do - better to use compactOs. It is worth compressing C:\Windows\Assembly and C:\Windows\Installer though.

Thanks. I do not like compressing folders with the /c switch. I will repack items as needed with the /EXE:LZX switch. Also, the /f switch sounds problematic. What about already compressed items?

As for Windows folders, ASSEMBLY seems like a good candidate but INSTALLER has got mostly already compressed files. Will do some tests though.