Page 1 of 2 1 2 LastLast
Results 1 to 20 of 25
  1. #1
    Senior Member Mr Alpha's Avatar
    Join Date
    Jul 2006

    Where those writes to the SSD comes from

    I got curious about where the writes to an SSD really comes from. So the other day I setup Process Monitor to capture a trace of all writes to my SSD and left it running for 24 hours (in reality 24 hours and 16 seconds). There was some surprises in there so I thought I would share my results.


    The Setup
    i5-2500k@4.7GHz on a P8P67 with 16GB DDR3-1333 RAM.
    Radeon HD 5970@850/1100MHz
    Intel 320 300GB SSD plus various hard drives.

    I have moved My Documents, My Music, My Pictures, My Videos and Spotify’s cache folder to a hard drive. Windows, all programs, all games are installed on the SSD. Except for what I moved all user profile stuff (appdata and such) is on the SSD.

    I avoided doing anything crazy that would produce a lot of writes like Virtual Machines, Mathematica or Bitcoin. Mostly what I did was surf with Firefox, play BF3 and fiddle with what I am supposed to be working on in Word. I had a x264 encode running in the background but it did all its reading and writing to a hard drive.

    The memory usage stayed modes throughout the test, around 5 GiB.


    The Results
    Total amount of data written was: 26.6816 GiB

    I made a bar chart of the processes that wrote the most. It is cut off at 50 MiB.

    System comes out at the top of the list. This did not surprise me. I was expecting windows to be the biggest writer.

    Firefox on the second place did surprise me though. The amount of writes it put out is almost the same as System. Also, I should mention that I have moved the Download folder to a hard drive so any download I’ve done is not part of the writes seen here.

    In third place is carboniteservice.exe. That this one did lot of writes did not surprise me. It is my cloud backup solutions and I have it liberally updating everything in my user folders so it constantly needs to make note of what has changed and needs to be updates.

    Chrome did more writes than I was expecting. I do all my surfing on Firefox because of its better handling of large amounts of tabs. The only thing I had open in Chrome was BF3’s battlelog since I’ve had some problems with it in Firefox Aurora.

    Volume Shadow Copy Service, vssvc.exe, did produce some writes but not anything exceptional.

    MsMpEng.exe is Windows Security Essentials, Microsoft’s free Antivirus solution. That it produced a bunch of writes is not a surprise. It is still quite modest.

    That CCC.exe, Catalyst Control Center, show up amongst the top writers was a surprise. It only wrote to two locations: C:\ProgramData\ATI\ACE\Profiles.xml and C:\Users\admin\AppData\Local\ATI\ACE\Profiles.xml. I have no idea why it is doing this.

    Spotify still did end up producing some writes to the SSD even though the cache was moved to a hard drive. I was playing Spotify a good chunk out of the 24 hour test.


    The Details
    I made a chart of the most written to files of System in hopes of figuring what it was doing. It is cut off at 100 MiB:

    The thing that dominates this chart is the pagefile. At no time during this test was I memory constrained. I seems like Windows does make extended use of the pagefile even when it has gobs of RAM to work with. Not what I was expecting.

    Many of the other locations written to by System are the same as written to by Firefox, Chrome, CCC and Spotify. Some sort of management maybe?
    Then there is the $LogFile, $Mft and $BitMap, which all are part of the NTFS structures. For the record the total writes by all processes to those three is 1349.52 MiB.

    I also made a similar chart of the most written to locations by Firefox. This one is also cut off at 100MiB:

    The session file tops the chart. This immediately gives a clue as to what is causing Firefox to write so much. Eyeballing the trace it looks like firefox is writing the session to disk every 30 seconds or so. Crash recovery! Firefox will restore a session after a crash. In order to do that it has to write the session to disk. It apparently does this every 30 seconds, and combine this with the fact that I have a large session of 100+ tabs this means ~1.5 MiB of writes every 30 seconds.

    Writes to the SQLite database files for cookies, webappstore, places and urlclassifier happen on the same frequency, presumably as part of the crash recovery as well.

    Since writes to the cache by Firefox is spread out over multiple files it would not show up in this chart. So I added up all the writes to the cache folder, and that is 165.54 MiB. Not a significant part of total writes.


    I found this interesting so I thought I should share.

  2. Thanks!

    bing (01-15-12), diaz (01-11-12), EarthDog (01-12-12), hokiealumnus (01-18-12), MattNo5ss (01-11-12), notJUSTguitar (01-16-12), Super Nade (01-17-12)

  3. #2
    Member diaz's Avatar
    Join Date
    Aug 2007
    Location
    Canada
    Fantastic writeup. You have class sir.


    Definitely gives you an insight as to what settings are useful or not on your browser..

    Just not sure what can be done about the pagefile. Maybe it has to do with the browser activity as well. Pagefile is pretty much non-negotiable
    \m/ OverClockers mATX L33T Club \m/ >>>JOIN NOW<<<
    Main Rig
    i5 3570k
    EVGA GTX 680

    Asus Maximus V Gene mATX
    Silverstone TJ08E mATX
    16G Corsair Vengeance
    Corsair H80

    Silverstone Strider Plus 850
    Crucial M4 256G SSD // Seagate 750G 7200.12 Storage

    Recommended PSU's - True/Tested/***/Intel C2D/Q/X Thermal Designs Explained
    Heatware

  4. #3
    5up3r m0d3r4t0r
    Overclockers.com Editor

    MattNo5ss's Avatar
    Join Date
    Aug 2008
    Location
    AL
    Author Profile Benching Profile Heatware Profile
    Nice job and very informative

    Looks like it's a good thing I don't use a pagefile and have crash recover off in FireFox
    i7 4770K | ASRock Z87M OC Formula | 2x8GB Crucial Ballistix DDR3-1600 8-8-8-24 1.35v | EVGA GTX780 SC ACX | ASUS Xonar Essence STX | 256GB OCZ Vertex 4 | SeaSonic X750
    Pentium G3258 | ASUS Z87I-Deluxe | 2x8GB Crucial Ballistix DDR3-1600 8-8-8-24 1.35v | 5x2TB RAIDZ | Corsair CX430

    My Overclockers.com Articles | HWBot Profile | Heatware (101-0-0)

    Projects: Copper-Framed, MDF Station | PVC-Framed, MDF Station | Custom Cascade Cart/Case | Untitled TJ07 Build


  5. #4
    Member diaz's Avatar
    Join Date
    Aug 2007
    Location
    Canada
    Crash recover still runs in the background on some browsers even when the option is disabled..
    \m/ OverClockers mATX L33T Club \m/ >>>JOIN NOW<<<
    Main Rig
    i5 3570k
    EVGA GTX 680

    Asus Maximus V Gene mATX
    Silverstone TJ08E mATX
    16G Corsair Vengeance
    Corsair H80

    Silverstone Strider Plus 850
    Crucial M4 256G SSD // Seagate 750G 7200.12 Storage

    Recommended PSU's - True/Tested/***/Intel C2D/Q/X Thermal Designs Explained
    Heatware

  6. #5
    Senior Member Mr Alpha's Avatar
    Join Date
    Jul 2006
    Bonus Chart:

    In this chart I simply counted the number of individual writes of each size. This is out of a total of 1 434 592 writes. I should mentions that roughly half of the writes done actually matched up cleanly with the power of two numbers in the chart. What I've done is add them up, so that, for example the 4 KiB bar includes all writes from 2049 bytes (2 KiB +1B) up to 4096 bytes (4KiB exactly).

    Interestingly enough there were 5 writes which were 0 bytes. I'm not quite sure what the point of them were.

    The 0.5 KiB column is quite high but there were only 23 713 (~7.8%) writes that were exactly 512 bytes. Most were a lot smaller. The average size was 90.636 KiB.

    The other extreme is the 4 KiB size where 534 915 (~95%) were exactly 4096 bytes. This was also by far the most common write size.

    32 KiB was the size used by Firefox when doing its session backup so that is why that column is so big.

    The single biggest write was 41 639 936 bytes or 39.7109 MiB.
    Last edited by Mr Alpha; 01-12-12 at 04:50 PM.

  7. #6
    Driven insane by lack of effort Mutterator
    Overclockers.com Editor
    First Responders

    EarthDog's Avatar
    Join Date
    Dec 2008
    Location
    Stuck in Maryland...
    Author Profile Benching Profile Folding Profile Heatware Profile
    Excellent information Mr A... thanks for that!

    "We have more information and more ways of accessing it than ever, yet seem increasingly less inclined to do so."- Michael Wilbon

  8. #7
    Senior Member Mr Alpha's Avatar
    Join Date
    Jul 2006
    Second bonus chart. This one is interesting, but it does suffer from some methodological shortcomings.

    What I've done is to try and estimate the ratio of sequential to random writes. I've defined a sequential write as one where it starts off from where the previous write ended. Random writes are defined simply as those writes that aren't sequential.

    I've classified sequential writes in the data as those writes where the write is to the same file as the previous write and the write's offset is equal to the previous file's offset plus the length of the write.

    One problem with this is that it will miss sequential writes where one write is to the end of one file and the following write is to the beginning of the next file. But I do not think this is a common case and so is not significant.

    The bigger problem is the assumption that the files are laid out linearly, ie that they aren't fragmented. In reality files on an SSD likely are fragmented and so the number of random writes is higher. So what I present really is the amount of random writes I would have had had the drive been perfectly defragmented.


  9. #8
    Member Mpegger's Avatar
    10 Year Badge
    Join Date
    Nov 2001
    Location
    NYC
    Heatware Profile
    Quote Originally Posted by Mr Alpha View Post
    I got curious about where the writes to an SSD really comes from. So the other day I setup Process Monitor to capture a trace of all writes to my SSD and left it running for 24 hours (in reality 24 hours and 16 seconds). There was some surprises in there so I thought I would share my results.

    The Results
    Total amount of data written was: 26.6816 GiB
    At least I know I'm not going crazy.

    I've made a post or two about the amount of writes my main OS/Drive drive gets, in the hope of getting help moving the writes off the SSD onto a mechanical drive to help preserve its life, once I install it with a fresh install of Windows as well. Most seem to still think that average daily writes for average usage is somewhere around the single digit GiB range and tell me not to worry, and that's without moving anything to a mechanical drive, such as the \Users or \Temp. Here I sit with my main OS/Data drive hovering around 113GB average writes per day, and almost 7.95TB total since I started keeping track back on 11/7/2011, and I get the sense that my post is just being looked at like there's something wrong with my totals.
    Main: NZXT Switch 810 | ASRock Z97 Extreme4 | i7 4790K| 32GiB | 780Ti
    ESXi Server: Lackrack Enterprise Edition | Dell R710 | 2 x Xeon X5570 | 96GiB | 14(28)TB ZFS-Raid10

    -----------------------------
    [GB ≠ GiB] [MB ≠ MiB] [kB ≠ kiB]
    "Apparently, Plaintiff believes that he could sue an egg company for fraud for labeling a carton of 12 eggs a “dozen,” because some bakers would view a “dozen” as including 13 items." - Western Digital 2006

    "One World, One Web, One Program" - Microsoft
    "Ein Volk, Ein Reich, Ein Führer" - Hitler

    (Microsucks) Avatar and quote on loan from AntmanMike
    Heatware

  10. #9
    Senior Member Mr Alpha's Avatar
    Join Date
    Jul 2006
    Quote Originally Posted by Mpegger View Post
    At least I know I'm not going crazy.

    I've made a post or two about the amount of writes my main OS/Drive drive gets, in the hope of getting help moving the writes off the SSD onto a mechanical drive to help preserve its life, once I install it with a fresh install of Windows as well. Most seem to still think that average daily writes for average usage is somewhere around the single digit GiB range and tell me not to worry, and that's without moving anything to a mechanical drive, such as the \Users or \Temp. Here I sit with my main OS/Data drive hovering around 113GB average writes per day, and almost 7.95TB total since I started keeping track back on 11/7/2011, and I get the sense that my post is just being looked at like there's something wrong with my totals.
    Since I got my drive in May 2011 I've totaled 20.5 TiB of writes. That makes an average of ~85GiB per day. And I know I was averaging north of 100GiB per day for a while there so I don't find your totals unbelievable. With a good SSD I still don't worry.

  11. #10
    Member Mpegger's Avatar
    10 Year Badge
    Join Date
    Nov 2001
    Location
    NYC
    Heatware Profile
    Quote Originally Posted by Mr Alpha View Post
    Since I got my drive in May 2011 I've totaled 20.5 TiB of writes. That makes an average of ~85GiB per day. And I know I was averaging north of 100GiB per day for a while there so I don't find your totals unbelievable. With a good SSD I still don't worry.
    Have you moved anything off the SSD during Windows install, such as the \Temp, \Users, or \ProgramData? I plan on moving at the very least the \Temp folders off the SSD, and more likely then not, then \User folder as well.
    Main: NZXT Switch 810 | ASRock Z97 Extreme4 | i7 4790K| 32GiB | 780Ti
    ESXi Server: Lackrack Enterprise Edition | Dell R710 | 2 x Xeon X5570 | 96GiB | 14(28)TB ZFS-Raid10

    -----------------------------
    [GB ≠ GiB] [MB ≠ MiB] [kB ≠ kiB]
    "Apparently, Plaintiff believes that he could sue an egg company for fraud for labeling a carton of 12 eggs a “dozen,” because some bakers would view a “dozen” as including 13 items." - Western Digital 2006

    "One World, One Web, One Program" - Microsoft
    "Ein Volk, Ein Reich, Ein Führer" - Hitler

    (Microsucks) Avatar and quote on loan from AntmanMike
    Heatware

  12. #11
    Senior Member Mr Alpha's Avatar
    Join Date
    Jul 2006
    Quote Originally Posted by Mpegger View Post
    Have you moved anything off the SSD during Windows install, such as the \Temp, \Users, or \ProgramData? I plan on moving at the very least the \Temp folders off the SSD, and more likely then not, then \User folder as well.
    Nope. The only thing I've moved is the documents, pictures, videos and music folder as well as the spotify cache.

    Here is a chart of the number of writes I had to those three paths:

    Since the Firefox profile is in AppData under the user profile all Firefox's writes went to /User. /Windows/Temp had practically no writes at all, and /ProgramData was modest.

  13. #12
    notJUSTguitar's Avatar
    Join Date
    Jul 2011
    Location
    MN, USA
    Benching Profile Heatware Profile
    Thanks for posting this...interesting.
    I always use firefox and leave it open all day. Wouldn't ever think it was writing that much to my SSD!
    i7 2600K (56x chip)
    Asus Maximus IV Gene-z/GEN3 Z68
    MSI R7970 Lightning
    8GB G.Skill Sniper 1866Mhz
    Multiple SSDs and TBs of HDDs :)
    OCZ 700W ModXtreme Pro PSU
    Asus VH232H 23" LCD x3 in eyefinity/6036X1080 Resolution
    Retired AMD Rig
    AMD Phenom II 1090T | GIGABYTE GA-MA78GM-US2H (Rev. 1) | XFX Radeon HD6970 | | 4GB Kingston HyperX DDR2 memory running at 1066Mhz | OCZ VERTEX 2 60GB SSD | Multiple SSDs and TBs of HDDs :) | OCZ 700W PSU | HP-Debranded 23" 1080P LCD

  14. #13
    Member ziggo0's Avatar
    10 Year Badge
    Join Date
    Apr 2004
    Location
    La Porte, Indiana
    Guess this is why I see a lot of SSD guides recommend moving the firefox cache off the SSD.

  15. #14
    Member Randyman...'s Avatar
    Join Date
    May 2004
    Location
    Houston, TX
    Quote Originally Posted by Mr Alpha View Post
    Since I got my drive in May 2011 I've totaled 20.5 TiB of writes. That makes an average of ~85GiB per day. And I know I was averaging north of 100GiB per day for a while there so I don't find your totals unbelievable. With a good SSD I still don't worry.
    Agreed 100%. I ran my pair of X25M G1's in RAID-0 for well over 2 years with everything running off it (minus my multiple TB of Data Files). Page file & everything. While I haven't checked the total useage, I know it is pretty high. Yet the drives still run like new after a Secure Erase now and again.

    Bottom line? I'm not worried about "wearing out" my SSD's in the slightest. And I CERTAINLY would NEVER ponder moving my Page File or any Cache to a mechanical drive when my system has SSD's in it!!! That's tossing out the baby with the bathwater

    A Descent SSD running everything under the sun = No Worries for years and years to come...

    Nice legwork none-the-less!!!
    Randy V - Audio-Dude/Musician/PC Guru/Crazy Guy

    PC#1 (Main Rig) : Lian Li PC-V1010 / P8Z68-V-GEN3 / 3750K @ 4.5GHz + Ven-X / 16GB G.Skill DDR3-1600 / HD5770 "XXX" 1GB / Samsung 830 256GB SSD / (6x) 2TB 5K3000 on Areca ARC1222 in RAID-6 / Seasonic X660 PSU / 2407WFP-HC / RME "Multiface" 38 Ch. Audio I/O / Dynaudio AIR-15 + AIR-BASE-2 Studio Monitors
    PC#2 (Realtime DAW) : Lian-Li PC-K65B / Sabertooth X79 / i7-3820 @ 4.8GHz + TRUE / 8GB RipJaws DDR3-2133 / HD6570 / 120GB Intel 520 / 4x 1TB on Areca ARC-1210 in RAID-5 / RME "HDSPe MADI" 128 Channel Audio I/O / 2x SSL AlphaLink MADI AX / 48 Mic Inputs + Fully-discrete Mic Preamps + 4260Watt PA System with 5x 18" JBL Subs :-)
    NAS#1: NSC-800 ITX Case / Asus P8H61-ITX / i3-2120 / (8x) 1TB 7200.12's in RAID-6 on Areca ARC-1220 Card
    NAS#2: 12TB ReadyNAS Ultra-4+ / (4x) 3TB 5K3000's
    And 7 other i7/i5/C2D/C2Q PC's

  16. #15
    Member Brando's Avatar
    Join Date
    Jan 2006
    Location
    Brandonia
    I've been using firefox every day on my vertex 3 that I got on the first day of release plus installing\uninstalling games. It's still at 100% health according to the ocz toolbox thingamajig. Don't trip!
    []Intel 3570k 4.4ghz~Asus P8Z77-V pro~TRUE spirit 140 power[]Mushkin Blackline 2x4gb[]Gtx 780 direct cu II oc[]Dell U2713HM[]Samsung 840 Evo 500gb~Spinpoint F3 1tb[]Pioneer BDR-206[]Corsair AX850[]Fractal Midi R2[]Leopold Tenkeyless~Deathadder 2013[]Harman Kardon HK990~Denon AH-D7000[]

    SELLER FEEDBACK

    LIAN LI PC-V1020A FOR SALE

  17. #16
    Senior Member Mr Alpha's Avatar
    Join Date
    Jul 2006
    Quote Originally Posted by Brando View Post
    I've been using firefox every day on my vertex 3 that I got on the first day of release plus installing\uninstalling games. It's still at 100% health according to the ocz toolbox thingamajig. Don't trip!
    Well with a Vertex 3 you are in a very good position since it does compression and dedupllication. The session is stores as json in a textfile, and text compresses really well. My 1.7 MiB sessionstore.js file compresses down to 145 KiB. Add to that the fact that your session probably stays mostly the same in 30 seconds so it is mostly the same data being written. This allows SandForce to avoid writing most of it by simple deduplication. So for you running Firefox probably doesn't have any measurable effect on the lifespan of the SSD.

    Quote Originally Posted by ziggo0 View Post
    Guess this is why I see a lot of SSD guides recommend moving the firefox cache off the SSD.
    As I mentioned, out of the 9899 MiB written by Firefox, only 165.54 MiB (or 1.7%) were written to the cache. So I would say moving the Firefox cache is rather pointless. It would make a lot more sense to move the Firefox profile.

  18. #17
    Driven insane by lack of effort Mutterator
    Overclockers.com Editor
    First Responders

    EarthDog's Avatar
    Join Date
    Dec 2008
    Location
    Stuck in Maryland...
    Author Profile Benching Profile Folding Profile Heatware Profile
    While making sense is one thing... is it necessary to move ANYTHING off your SSD these days?

    I mean outside of this method:

    Install W7
    Install Chipset drivers
    reboot
    Install VGA drivers
    reboot
    Run WEI (shows system its an SSD and disables several items for the drive like defrag, indexing, etc)
    If you need more space, shrink PF...if you dont hibernate/ system restore delete those files, and stop that from happening.

    Is there any other maintenance that should be done for a modern SSD?

    "We have more information and more ways of accessing it than ever, yet seem increasingly less inclined to do so."- Michael Wilbon

  19. #18
    Senior Member Mr Alpha's Avatar
    Join Date
    Jul 2006
    Quote Originally Posted by EarthDog View Post
    While making sense is one thing... is it necessary to move ANYTHING off your SSD these days?
    I would say no. Which is why I haven't moved anything off of my SSD beyond space saving stuff. My iTunes library is on a hard drive, not because I'm worried about writes, but not to waste SSD space on podcasts.

  20. #19
    Low Profile Senior bing's Avatar
    Join Date
    Jul 2006
    Location
    Indonesia
    Heatware Profile
    Mr.Alpha, how much in percentage did pagefile.sys consumed for write ? Since you have the spreadsheet for those numbers and easier to calculate it.

  21. #20
    Insatiably Malcontent
    Senior Member
    johan851's Avatar
    10 Year Badge
    Join Date
    Jul 2002
    Location
    Seattle, WA
    Very nice investigation! I'm glad you did this.

    The thing that dominates this chart is the pagefile. At no time during this test was I memory constrained. I seems like Windows does make extended use of the pagefile even when it has gobs of RAM to work with. Not what I was expecting.
    This isn't terribly surprising, actually. When Windows writes to the pagefile it's not necessarily taking that information out of memory. It's just writing in anticipation of having to page something out. The page will likely stay memory resident for use later unless something kicks it out. If everything's idle, it makes sense from a performance standpoint to prepare for disk swapping so that if it happens the system is less likely to grind to a halt.
    ASRock Z68 Extreme3 Gen3 | 2500K @ 4.6GHz | 2x4GB Samsung DDR3 | GTX 750 Ti 2GB
    120GB Crucial M4 | 2x 2TB Samsung F4 | Seasonic S12 600w
    y2 DAC --> Custom M^3 --> Custom LM3875 ChipAmp --> Modula MTs
    Dual Dell 2007WFP | Watercooled

Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •