Is keeping 30% of hard disk unallocated good for performance?

Question

I had read here that when hard disk is filled over 75% the hard disk slows down noticeably. So my question is If 30% space hard drive space is unallocated, then will the pc run smoothly? speaking smoothly, i mean is it should not take large time to load chrome and other applications. (for loading far cry 3 on defragmented disk it takes around about 15 mins. so I can take a cup of tea and return) for opening browser and simple stuff, loading time of 1 min is acceptable.(my phone is even faster for browsing internet as the browser starts quickly).

So back to the point. say for instance I have a 1TB hard dirve then keeping 300Gigs of memory unallocated so that it is not written. so the pc will not noticeably slow down. Waiting for programs to load feels worse then having that 300Gigs allocated.

This is theory I haven't tested in practical. So I wanted to ask this question.

Answer 1

First, the general answer "no", because the point at which the system slows down because of drive use, depends on the format, cache, and types of allocation being done.

Also you are using the word wrong. Do you have "unallocated space" or "unused space"

"Unallocated" means you do not have the drive partitioned to the full size of the drive.

a 1TB drive, with a single full size partition may format to the 900G range (mine fmtd to 930G +/-) So "unallocated" means when you originally set-up the drive, you manually created a partition of say .. 800G .. and if you went into Disk Management (windows) you would see "unallocated" for 150G (+ or - a few) on your drive, after the main partition.

What they meant was "un-used" or "not filled" with data. So looking in "my computer" you would see 300GB free of 930GB (my case, my 1tb drive, and drives sometimes format differently)

There is some truth to not filling a drive full. The fuller the drive, the potential exists to have fragmentation that could cause more seeking than would be needed, because the files were laid out a few here, a few there and so forth. When the game (or app) starts it may again take additional space for temporary files, and when done toss the space used, and then the next time start up for temporary files in some other space on the drive..

Think like potholes on a road, get a pot hole.. you fill it in. Sometimes the filler is a little higher than the road sometimes not .. but most potholes are weak spots now ... and as its driven over, the filler starts to break up and come out. If you were to compare a before and after, the pot hole after a fill and later loss of material, will never be the same shape or have the same open area as it initially had ..

So, say the temp space is set to initially take 10243850 bytes and adds temp space to its "filler" 4096 bytes at a time. It found a spot that was 10244090, so its 10243850 temp file fit, but it can't grow there, and has to add a chunk reference to another open spot on the drive that could be within 1/4th disk rotation, or could be 1/2 a rotation away ... like the other side of a circle directly opposite the original data .. now to read from both parts its got to wait to read that other chunklet ... till half the drive spins past.

That is what adds to file latency in reading ... chunklets of the file in different areas. There are all sorts of schemes, mechanisms at play on a drive, and in the OS trying to reduce all of this latency ...

Now enter how much the drive is in use .. your program wants 10243850 initially ... if it can't find a contiguous block of space large enough, it may tell you your drive is full, or it may allow the drive to split that temp space up in to smaller chunks just so the program can reference it as "one" ... again adding that latency, because now the drive is forced to get a bit here, bit there, etc.

As Ramhound pointed out .. loading something like FarCry is dependent largely on CPU & RAM, how efficiently it uses RAM, and is dependent on how it wants to use space on the drive.. does it want to grab some temporary space to quickly swap or cache stuff to its own "temp" file for your inventory or for things it can't fit all in RAM now? possibly.

The real killer in performance from day one, to 3 years later when your PC seems like its the box turtle out for a leisurely stroll, are changes in the efficiency of Windows. Patches loaded, contiguous free space, driver performance, CPU throttle (if your cpu fan has a lot of dust and dirt on it, it is no longer cooling as well as it did, your cpu maybe throttling down some) etc. etc. etc. The last bit of that as another user pointed out, helper programs that slow things down. Install iTunes, and even though you may not be actively using iTunes itself, it has bits and pieces it loads and the system runs non-stop, so that should you decide to start iTunes (or click a link in a browser for an iTunes song, stream, or show) the main iTunes process loads faster or like clicking the link starts the play process faster than if it had to read the entire program into memory from the start. (don't mean to pick on itunes, its just common enough many people have it) Some of these conditions match the typical case of bloatware. Java does the same thing, so do many adobe products etc etc.

Biggest performance gains are changing spinning sata drives to SSD, additional and/or faster speed RAM, more CPU ... if you have the ability to swap say an i3 for an i7 on an LGA 1150 socket motherboard, you will gain leaps of performance (CPU support isn't just based on socket but chips on the board, bios etc) RAM & CPU support are motherboard dependent where swapping SSD sata for spinning disk sata is usually not.

Generally you would see generational increases with CPU change, and see order of magnitude access and latency drops for Sata Disk to Sata SSD, with RAM, unless you started with really slow RAM, your performance gain on speed won't be effective but may yield still additional frame-rate differences, and generally adding more RAM means less swapping to disk.

Answer 2

The "Keep 25 to 30% free space" refers to SSD disks. The TRIM function and how SSD's work make that they remain fast as long as there is at least 25% of free disk space available.

This does not apply to normal disks. Given you are talking about a 1TB disk, its likely that you are talking about a mechanical drive.

They too can slow down, but for different reasons, such as fragmentation.

Answer 3

Most likely your sluggish user experience is too many apps running . Reducing the drive size is not the bottleneck for seek times.

The test is run in safe mode and compare browser random web search. If you can get 1 page in a second or 2 . It is tuned well. If not then lots of pruning to do. Start by running msinfo.exe and save NFO as a zip attachment.

This may be a long or short process depending on what is installed. e.g. sluggish AV suites.

Answer 4

Malarkey.

The idea of needing to keep a double-digit percentage of your disk free sounds so much like needing to have twice as much disk space as RAM. Mark Russinovich discussed that in "Pushing the Limits of Windows: Virtual Memory":

"There’s no end of ridiculous advice out on the web and in the newsstand magazines that cover Windows, and even Microsoft has published misleading recommendations. Almost all the suggestions are based on multiplying RAM size by some factor, with common values being 1.2, 1.5 and 2. Now that you understand" [more...] "you’re well positioned to see how useless such formulas truly are."

If I buy a drive that is 1 TB, I expect it to be able to store 1TB. I don't expect to need to buy something at least 30% bigger just so that I can waste 30% of its capability.

Now, the reality is, that having free disk space can be useful. Whether it is useful for what you do, or not, depends on what you're wanting to do with the space. Which operating system you use could have an impact, as well as details like how much you are re-reading common data and how frequently you are writing data (particularly in comparison to the number of times the data is read). You may have multiple convenient choices of filesystem types, and that may also impact things. Or not. There's quite a few variables that could cause these effects.

In practice, I've had numerous systems that ran rather low on space. With Win9x, it could be run down to multiple megabytes and still function okay. With Win7, it may be nice to have a gigabyte or four free. But dipping below 300GB free won't grind your system to a screeching halt.

I would think you're far more likely to get notably more speed using other strategies. Defragmenting is a freebee method. Switching from mechanical disks to SSDs are likely to have a much greater impact on speed. Using optimized (possibly meaning "expensive") hardware to use RAID 0 may also have a greater effect.