recommended free space on system drive

[RabbieBurns]

having a discussion here in the office.. what is the microsoft free space % for the system drive to operate windows.

Got a laptop with a 64gb ssd and our soe is about 50gb and Im being told that 12gb free space is not enough to run an windows environement.

Is there any technical or microsoft backing to this claim?

[glennda]

we run all our machines across the site (900) with around 20gb free (all with 59gb partitions). not had a problem so far.

[SYNACK]

10-15% free needed for defrag which is not an issue with an SSD, you want enough room for the active userprofile and any that may be cached, room for the pagefile assuming you don't have tonnes of RAM and room to run updates. The Windows 7 SP1 requirement for the beta of SP1 was 3.3GB of free space after the 900MB installer had been transfered across Windows 7 SP1 System Requirements

With all of this you should be able to run in 12GB of space alright as long as stuff like previous versions is switched off and updates are run frequently. You should also make sure that there are not too many user profiles on there but all and all you should be alright.

I usually try to have an absoloute minimum of about 4GB free myself. That is on my personal 'scratch' OS that gets flushed and reinstalled at the first sign of insolence.

[Michael]

Windows manages the page file really well, so disk space shouldn't be a problem. You'll only notice things slowing up if you have below 3GB of space. As always with modern Windows OS'es, plenty of RAM 2GB+ will keep things running at a decent speed.

[mrbios]

Running 40GB SSDs in 2 classrooms, 29GB used, no problems what so ever and don't foresee any in the near future even if more space is used.

like Michael says, so long as you have more than 3GB or so spare you're fine.

[RabbieBurns]

thanks for the replies.. @SYNACK , thanks for the link, which provides info about possible reqiurements for future SP's etc.. (also, can you elaborate on the defrag / SSD situation please?)

What I'm really after is something from a cite-able source (no offense intended to edugeek or the rest of you guys but Id rather not link to my own threads as a source of evidence) that confirms that having less than 10% of the disk free does not cause detrimental effects on the operation of Windoes.

[mrbios]

(also, can you elaborate on the defrag / SSD situation please?)

Defrag is disabled for any SSD drive, as they don't have the problems a HDD has with regards to finding a block of data. Doesn't matter where the data is as it's just accessing a physical memory rather than having to find it with a spinning disc + spindle.

To put it simply anyway. Also defragging an SSD would just incur loads of unneeded random reads and writes which are detrimental to an SSDs life and performance.

[SYNACK]

It looks like your biggest contention for free space may not be Windows: Non-OS SSD Performance with minimum free space [SOLVED] - Hard-Disks - Storage

According to this the write leveling and large block sizes mean that the less free space you have the slower it writes. According to the above the Intel community recommended 10GB free for uncompromised write performance. Given the safety margins of a few GB for Windows Updates 8-10GB may be a good median. Looks like some recommend 35-40% free

Generally speaking, SSDs perform best when they are left with around 30-40%
of the drive unused; the rule of thumb is, the more free space the better. If
you think this is nonsense, read
an official white paper on the matter (do not skim it, READ IT) -- it will
show you why your performance is sub-par.

SSD writes are very slow, reads are...http://www.stec-inc.com/downloads/wh...prise_SSDs.pdf


The write performance may not be much of an issue but the lower the free space the less of their potential you'll be using for stuff like profiles. As docs and stuff are probably mapped to a server this limits the impact but it is something to consider.