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Root Increasing SD Cache for Significant Read Improvement!

Discussion in 'Android Devices' started by SupremeDork, Feb 27, 2012.

  1. SupremeDork

    SupremeDork New Member
    Thread Starter

    Nov 28, 2011
    Hello fellow Commando users! First thread (and post for that matter). :) Cutting to the chase:

    While I know there is a thread elsewhere on androidforums about this, I'm sharing these tips as a Commando user.

    Tech Stuff:
    • Casio G'zOne Commando
    • Android 2.3.3 rooted
    • Adata Class 10 16GB microSD card
    • ...what else am I missing???

    I've gotten a significant increase in SD read speeds on my Commando as a result of increasing the SD cache size. The default is 128k. You can change the value using the free app SD Booster. It changes the value found in /sys/devices/virtual/bdi/179:0/read_ahead_kb and can set the value upon boot if you choose, otherwise it reverts to 128k. I used SD Tools to benchmark the r/w speeds.

    NOTE: Apparently, closing and reopening SD Tools between each test provides more accurate results. I dunno for sure, but I did it anyway. ALSO, I didn't test in numerical order. I started with 2048k, then 128k, 4096k, 1024k, and bounced around some more.

    I'm not listing write speeds because it only increased by a couple MB at most and never went over 13MB/s. That's not possible to increase much anyway.

    Read Speeds:
    • 128k: ~20MB/s
    • 1024k: ~31MB/s
    • 2048k: ~29MB/s
    • 3072k: ~32MB/s
    • 4096k: ~30MB/s
    • 5120k: ~31MB/s
    • I had caught on to the possibility that odd multiples of 1024 were giving faster read speeds, so I went up even more out of curiosity.
    • 7168k: ~32MB/s
    • 8192k: ~31MB/s

    I'm 100% sure your results will vary. What I really wanted to communicate is the interesting find about the odd multiples of 1024, and hopefully bring all this to those Commandos that wish to be the next Seabiscuit.

    DISCLAIMER: While in my research I did not find anything to be concerned about with raising the cache size, I didn't write any of the apps and am not forcing you to do this. Thus, I cannot be blamed if your phone grows solar gills and flies into the Sun... or something. :eek:

    Have anything to correct/share? Please enlighten me! :)


    colinnc, r_hippy, tailez and 2 others like this.
  2. paxchristos

    paxchristos Well-Known Member

    Aug 27, 2011
    The increases in multiples of 1024 are because you're moving up in megabytes (interesting that 3mbs and 7mbs are similar)

    Like you mentioned about boot, the problem is that unless you have a kernel/ramdisk that supports build.prop edits (i.e. a custom kernel) this won't stick when you reboot... (unless the app allows set on boot, or you run an script at boot, which I think you mentioned)

  3. Unforgiven

    Unforgiven -.. --- - / -.. .- ... ....

    Jun 23, 2010
    Douglas, MA
    I'm sure the 1024 is related to the fact that it is 2^10 and most storage is done in bytes. 1k is actually 1024 bytes even though many folks still think it translates to exactly 1000 bytes.
  4. SupremeDork

    SupremeDork New Member
    Thread Starter

    Nov 28, 2011
    Basic computer science in my first thread? Really guys? :p

    I forgot to mention that in real-world use, the tweak shines through.

    For example; ES File Explorer opens in what feels like half the time! Pictures and especially videos and animated gifs load almost instantly now!
  5. r_hippy

    r_hippy Well-Known Member

    Was weird. Save # for the cache and was different every time I ran it




    Thanks for the tip /info

    Also saved this I checked afer a few reboots
  6. r_hippy

    r_hippy Well-Known Member

    ran all day today flying

    Not sure if it's related but since the root
    I did not noticed a hug increase
    even after getting rig of the blot
    But after this she has new life...

    along with some other tweaks for the battery
    I'm not charging it 4x a day
    Did 9 hours today with 31 % left
    that has to be unheard of...

    thanks everyone
  7. bestaudioguy

    bestaudioguy Well-Known Member

    Jan 9, 2012
    Owner of ClearCom Professional Audio & Video
    Here are my reading after setting the cache to 2048:trytofly:

    Attached Files:

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