Inconsistent reporting of used hard drive space

[buggaby]

I'm running Windows 7 on a Core i7. The c drive is a 75GB solid state drive. It says that I have 13GB free (~60GB used) but when I navigate to the drive, select all and check the size, it comes up with 30GB used. I have hidden folders displayed.

Can anyone tell me what happened to that extra 30GB? Thanks!

 

[tomatthe]

Run this, http://windirstat.info/ it will show you where the space is being used.

Very likely it's pagefile, hibernation file, or system restore points.

 

[buggaby]

My computer guy friend just told me that it's likely the swap file. We have 16GB of RAM and at 1.5x, the swap file should be 24GB. There's also the suspend file, I guess.

My question is why does a SSD need a swap file? I was under the impression that swap (or paging) files reduce seek times, but there aren't any with SSDs so, I should be able to just turn off the swap file, right?

Thanks!

 

[tomatthe]

With 16Gb of ram you could probably turn it off and be fine. You could also reduce the size of it to the min, or move it to another drive. Swap files/pagefile are used when the machine runs out of ram and needs extra space, but with 16gigs of ram that is highly doubtful on your system.

 

[JackNaylorPE]

My question is why does a SSD need a swap file? I was under the impression that swap (or paging) files reduce seek times, but there aren't any with SSDs so, I should be able to just turn off the swap file, right?

The swap file has nothing to do with "being needed by the SSD". The purpose of the "swap file" is to swap data out of RAM and onto storage devices (SSD or HD) to make more room for new data. With 16GB of memory, you probably won't need it too much. Be aware though .....

a) Some programs, (i.e AutoCAD) make extensive use of the swap file. They force writes regardless of whether how much memory is available.

b) You lose the ability to capture dump files to diagnose crash issues however there is a work around

http://blogs.msdn.com/b/ntdebugging/archive/2010/04/02/how-to-use-the-dedicateddumpfile-registry-value-to-overcome-space-limitations-on-the-system-drive-when-capturing-a-system-memory-dump.aspx

b) Some programs / games have memory leaks .... so if you are using a long time, this can result in using all of your memory. It has been reported that some games won't start w/o a page file though not experienced this myself....however some programs (i.e. Adobe CS5) won't run w/o one.

c) Is prefetch enabled ? "Windows preallocates virtual memory in anticipation of a possible need for it, even though that allocated ay never be used. Without a page file, that allocation has to be made in real memory, thus tying up that memory and preventing it from being used for any purpose."

http://answers.microsoft.com/en-us/windows/forum/windows_7-performance/can-i-disable-swap-file-for-windows-7-32-bit-as/0bd8a75c-2607-4468-8342-c35ea82ea670

d) Evidence that it does anything performance wise in purely anecdotal or so marginal as to be insignificant. I have seen bigger increases just creating a separate partition for AutoCAD on a HD and using FAT32 on that small partition.

e) MS and detailed testing show that you can disable it but results in only marginal if any improvements.....and leaves with the issues above.

http://www.tweakhound.com/2011/10/10/the-windows-7-pagefile-and-running-without-one/

The hound is pretty clear on his conclusions after 11 months of testing. You "can" disable the page file if disk space is an issue but don't expect to see an observable performance difference.

 

[buggaby]

Best answer selected by buggaby.