Windows.iso Compression

[Arty]

how is the massive 20+gb windows compressed into 4gigs?

and how may i achieve that greatness on my compressions?

[Firearm2112]

kidnap bill gates and make him lend you his massive super computers with 100 intel 5960X 

[Arty]

kidnap bill gates and make him lend you his massive super computers with 100 intel 5960X 

, if it takes that much power to compress, decompression should in theory take that near amount of time?

[xox]

When I last looked, the windows 7 ISO files were only like 3/4 gigs

[Arty]

When I last looked, the windows 7 ISO files were only like 3/4 gigs

yea and it expands to what? 15-20+

[QueenDemetria]

When I last looked, the windows 7 ISO files were only like 3/4 gigs

I think OP is referring to how the ISO is only 4Gb on the disk, but after the installation it is 15+Gb.

 

Ninja'd lol

 

Edit: and on topic, just really aggressive compression. This cant be done on the fly(just look at how long it takes to install), but it is totally doable with modern compression algorithms(and I am referring to 15+Gb turning into 4Gb). Now what I can't understand is why can't Windows be a live DVD(oh wait, that gives the user too much freedom).

[xox]

yea and it expands to what? 15-20+

Yeah fair enough, my best guess is that smaller files (like text and icons) are easy to compress and you can achieve a 300% compression ratio with even the simplest compression algorithms... You know, basic parity and (in essence) shortening.

[ThatAngryGnome]

ITS A CONSPIRACY! GOVERNMENTS AND MAJOR BUSINESSES DON'T WANT YOU TO KNOW THIS SECRET! 

[Altecice]

Most of the Windows install is a central image that parts are taken from or included (depending on windows version). Hence why you can do the Windows Anytime Upgrade from any version to Ultimate without needing to download anything... more of the image is unlocked. Windows its self is quite small but other files do take up a lot of space (your pagefile for example is x2 your RAM so 8gb of RAM = 16GB pagefile so only 4GB left (ish) for the Windows install.

[Arty]

Yeah fair enough, my best guess is that smaller files (like text and icons) are easy to compress and you can achieve a 300% compression ratio with even the simplest compression algorithms... You know, basic parity and (in essence) shortening.

its what im seeing 2 with rar 5 1024mb compression smaller files getting down to50-70 percent

but to get it that tiny idk what thier using/ 

[Robin88]

I can't remember exactly what compression Microsoft uses, but it's a proprietary algorithm that works incredibly well for the kinds of files that make up windows, however, once those files are compressed, they're completely unusable in that format, they need to be decompressed before you can run Windows (which is one of the many reasons that microsoft couldn't offer a live CD/DVD even if they wanted to), so it isn't as though you could use it all the time to make Windows only take up 4GB, and like all compression techniques, it only works correctly on files that weren't compresed to begin with, so it wouldn't work on most video/audio.

Also like others have said, a lot of space in Windows is taken up by Hiberfil.sys, Pagefile.sys and System Restore, which aren't stored on the DVD/in the ISO, however, even if you delete Hiberfil.sys, reduce/remove Pagefile.sys, and turn off System Restore, Windows still takes up around 12-15GB, so as you can see, it's incredibly efficient at compression.

[TDP_Equinox]

A LOT of that space is windows updates. 
It only expands to about 10 gigs. 

[NeatSquidYT]

It's amazing how compressed it is though. I installed my W8 off an 8GB USB stick, and had some room left over.

[Mujteba]

kidnap bill gates and make him lend you his massive super computers with 100 intel 5960X 

[Thx And Bye]

Its not only about the algorithm it's also about the type of data you want to compress.

zip for example can compress ~4,5PB of data into 42kB (the data itself is useless, its just a proof of concept)

You can find the zip here: -> http://unforgettable.dk/

It may also be detected as malware by your antivirus because this kind of high compressed archives are used to crash your antivirus when it tries to scan every file in them. (and runs out of memory)

Also compressing is way more resource intensive than decompressing a archive.

And just to get a bit better compression you need also way more resources.

Just look at what 7zip says at (somewhat) most resource intensive settings compared to default:

[soarwiththesky]

I agree, very interesting!   I'd like to see this new browser Microsoft is apparently including in windows 10.