Big amount of written data to ssd (several gigabytes)

[soulburner]

Before you tell me this is not a Windows 8 issue but the software I use and how I use it, I need to clarify.

When I was using Windows 7, I monitored the written bytes to my SSD drive because I was worried about write cycles. I learned to forget about it and just use the disk and don't bother with stuff like moving the Firefox profile and cache to an HDD, which kind of kills the whole purpose of having an SSD. Anyway, after using the computer for a whole day, both me and my brother, the amount of written bytes to C: wasn't too big - around 1GB, sometimes more, sometimes less. This is without modifications to software - no Mozilla profiles, pagefiles, etc, were moved to HDD.

Now on Windows 8 it's a little weird. After a day of computer use (8 hours or more), I have between 6 and 11GB written to C:! I don't use too much applications - it's pretty much Firefox, an instant messenger, foobar, Gimp... there's just no way anything should write THAT much to the disk.

I tried running procmon, filtering the results by written files or filtering by C:\, but during monitoring there was almost nothing written to the disk. After using Firefox for a while, I check the written bytes and... additional 6GB suddenly have been written. So I moved the profile and cache folders to HDD, to see if it changes anything, but it did not, so I went back to using the SSD for them. My research was fruitless. I could not identify what is writing so much data. Firefox and the People app wrote the most, likely because of storing web cache on the disk, but the amount of these writes is very small and should never reach over 10GB within a few hours.

I use DiskCountersView to monitor the amount of read and written data. For a second, I thought this program might not be compatible with Windows 8 and show weird stuff because of that, but a friend of mine does not have this issue. He has about 1GB written, after a few hours of browsing the web, watching movies, etc.

I have scanned the whole system with the built in Defender, Malwarebytes Antimalware, SpyBot and they didn't even find something suspicious. The system is 100% clean. The situation did not change after reinstalling the whole system from scratch (due to other reasons). I don't use hibernation, only fast boot. System Restore very rarely creates new restore points and I doubt they would be big enough to generate over 10GB's of data.

So I ask here :) Is this normal for Windows 8 to write so much to the C: partition? If so, why? :p If it is not normal, then do you have any recommendations about how should I investigate further? I know this amount of writes won't suddenly kill my SSD (or at least shouldn't ;)) so I could probably forget about it, but putting SSD life expectancy aside... what could possibly be in those tens of gigabytes? :p

Thanks in advance for any tips.

[n_K]

What's your drives sector size? Each sector is usually about 4KB, spread unevenly across a drive, on the drive you also have 'blocks' of a set size, when you read or write to these blocks, you get or write to the WHOLE block so writing where 2 files are storage would require reading the contents, modify one of the files and then write back the new block. Maybe that's why firefox is using a lot?

If you've got an SSD, why have you not set firefox's cache to memory only?

[soulburner]

My disk is Kingston V200, 128GB. It has 4kB sector size, the NTFS partition has 4kB cluster size. Firefox is not the cause of the problem. Setting its cache to memory only is interesting and I'll read about that, but it won't eliminate my problem with ~10GB writes on a daily basis... because, as I said, I tested with the cache and profile folders move from the SSD to HDD. The SSD still had many gigabytes written to it on random occasions, usually when idle - say, I see 1GB written in DiskCountersView, I go out of the room for a few minutes, come back to my PC and see 6GB written :p

[HawkMan]

Have you been using Gimp while this has been happening?

[soulburner]

No, I haven't. That's the most weird thing - at least some of the huge writes occur when the computer is idle.

I also used Task Manager, Details tab, and added the column "I/O write bytes". No running processes ever have more writes than a few hundred megabytes, and after suming them up... it's still a few hundred megabytes, not dozens of gigabytes...

[soulburner]

I just wanted to add that I launched ARMA2 game on Steam, which is installed on the HDD. Launched it, tested it and exited. Disk writes on C: - 2GB. WTF?

[Ve7878]

I've noticed that the space used on C:\ varies a lot on Windows 8, I think it's to do with the way the system is shut down as after a reboot it will go back to 74GB available but if it's been running for a few days it goes down to about 70GB. I'm running a 120GB OCZ Agility 3 SSD but I'm not particularly fussed about this. I take the attitude that I bought the device to use it, not to keep thinking about how many write cycles it's doing. It will probably take years before it causes any issues with the drive at which point I would have upgraded anyway.

This seems to be consistent with the Windows 8 install on my netbook which also seems to free up a few gigs of space after being rebooted after being running for a few days.

[soulburner]

I don't care about the disk space used. It's pretty much stuck at 89-91GB free.

I disabled the hiberfile, disabled fast boot, disabled the pagefile. After booting and launching a few applications: ~100MB write bytes. That's how it should be. So i start up ARMA2 for 5 minutes. Exit. Writebytes: over 1GB.

The game is *not* saving anything but a few config files in Documents and %appdata% nearly a 1MB total.

So:

- Firefox is not writing gigabytes to disk

- games are not writing gigabytes to disk

- but diskcountersview says gigabytes have been written

I wouldn't care about this, as the SSD drive has been bought to be used and be happy about the speed gains. But, Windows 7 wrote about 1GB of data after a few hours of use. The same kind of use on Windows 8 generates tens of gigabytes of write files. A friend of mine with Windows 8 has a few hundred megabyte write files after a few hours of system and app use.

So, I don't really have a problem with SSD wear. I don't care, I'll buy a new one when this one dies. The thing that troubles me is what the hell is being written to the disk so much, to generate ~10GB of write files. Interesting thing is, my free hard disk space doesn't go below 89-91GB, ever. So it's also not my complaint, that I'm suddenly 10GB of disk space less. I am not. The total amount of disk write operations sums up to ~10GB per day, which is ~10 times more than on Windows 7. Is this how Windows 8 works?

[HawkMan]

Chances are, nothing, and the reported usage is wrong

[soulburner]

I thought about it too, that DiskCountersView is somehow not compatible with Windows 8, similarly to how LatencyMon and other DPC monitoring software are, and is simply reporting wrong.

But a friend of mine is also using Windows 8. His computer usage is similar to mine, too - 99% of the time is spent in Firefox. Default configurations on both computers. He tells me DiskCountersView is reporting several hundred gigabytes of write file operations.

As I said, I'm not paranoid about SSD wear. It just bothers me what the hell is going on :p

edit - could you run this program http://www.nirsoft.n...nters_view.html and tell me how much bytes you have in the Write bytes column, on the C: drive? Also, how long is your system running since the last restart. One more thing - due to how fast boot operates, shutting down the system and starting again, does not reset the counters. So the amount of write bytes can be huge if you have not restarted the system recently.

[HawkMan]

what does performance monitor say ?

[soulburner]

I'll monitor with performance monitor later today. Any tips on what I should do exactly? I don't think I ever used this tool before ;)

[jkral]

I have bad experience with Firefox - even with prefetch off and disk cache off, it writes over 2 GB of data per day with not heavy browsing. It seems it is because of permanent rewrite of approx 10 MB places.sqlite file. Every new web page or link open adds about 11 MB in Process Explorer I/O write bytes, the datetime of the file is changed but the total size is almost constant.

Anyway, rewriting of file consumes the same amount of work from SSD and it eats from its life...

If this is true assumption, thanks a lot mozilla & sqlite. It does not mean Chrome is much better :-) Try to watch process explorer for a while when browsing.

[BillyJack]

I can understand if you want to figure this out to know what is going on, but I would not worry about the SSD and its' life. The life of that SSD will outlast that computer and you are going to buy a new SSD for a new computer build before that drive ever looses space or performance. Get some sleep :)