"This nifty utility compacts your games without a performance hit"

[JamesD]

"Windows 10 includes tools to help you use less drive space, one of which is a compression utility called Compact. Normally you would access this through the command line. Now there is an open-source graphical interface available called Compact GUI that makes the built-in utility much easier to use, and less daunting to inexperienced users.
..."
http://www.pcgamer.com/this-nifty-utility-purportedly-compacts-your-games-without-a-performance-hit/

[+thanatos]

It was called DoubleSpace when MS-DOS 6 came out.

 

https://en.wikipedia.org/wiki/DriveSpace

[Keatah]

And they cause wicked fragmentation too.

[Video]

Could compress everything then defrag your drive too. Though I assume you run into the hitch of slowing down to decompress your data.

[Keatah]

Decompressing data is far less intensive than compressing data. And back in the 486 days, realtime decompression happened fast enough that there was an overall performance boost. The thinking is the less data over the bus the better.

[Keatah]

If you compress files in NTFS you get these little sequential chunks. While the HDD may not see sequential stuff as a fragment, it still is fragmented. And subsequent disk writes cause more fragmentation. And other files are eventually stuffed in between, so they're fragmented too.

 

Defragging after compression is a requirement for optimum performance, even on SSD. Otherwise your processor time is spent chasing after those tiny chunks at the file system level, as well as the SSD doing the same thing at the physical level.

[+-^CrossBow^-]

Except that you aren't supposed to be running any defrags on SSDs. In fact on my PC, the Intel Toolbox disables this automatically for all the SSDs installed in my system.

[Keatah]

No.

 

There's 2 types of defragging. Defragging the physical data on the SSD chips. And defragging the NTFS file system.

 

Conventional HDD + defraggers do both by default. They are lock-step with each other. Impossible to separate.

 

SSD does not. It introduces a 2nd hidden layer. The Controller -to- StorageChip lookup table. Windows can place data at sectors 50,000 through 60,000 for example, as record it as such in the NTFS MFT as 1 single file spanning those sectors. It is a defragmented file or single-fragment file to windows. As far as windows is concerned, it's done. The SSD may scatter that file into 500 pieces among many blocks. And Windows will never notice. And the processor will issue one IO request to get that file. Like a cluttered stock room - the ssd does the work and will run around and gather it for you and give you one box. One file. One request.

 

But Windows can and frequently does write a single file among many many different sectors in ITS OWN NTFS MFT table. Especially when multiple disk accesses are happening at once. The SSD will see this situation as many fragments. It will take many IO ops to retrieve that file. It will see file X as 500 separate fragments and issue 500 ops. The SSD will do the same amount of work behind the scenes, but now your CPU is babysitting a fragmented chart in the MFT, so to speak.

 

What windows thinks is in sector 900,000 may in reality be sector 454,221 on the chips themselves.

 

So, you never want to re-write the data on the SSD. But you DO want to rewrite Windows' own MFT or filesystem. It's called defragging the file system. Not defragging the data. And the purpose is to lower the amount of work your processor does.

 

There are more elegant explanations on the web.

[Keatah]

Let's put it this way. It is a good thing to defragment the filesystem's lookup table, or how Windows keeps track of files.

 

Don't worry about what goes on internal to the SSD. It will always be a fragmented mess in there, even on a virgin drive. The data is immediately fragmented for technical reasons.

 

And with a proper SSD aware defragmenter, only the filesystem's lookup table will be defragmented. This has the direct effect of reducing I/O ops - the command communication between processor and SSD.