Adjust and Boost Your SD Buffered Read/Write Throughput Performance.**REQUIREMENT** Rooted Phone and Root Privilege are Required Because This App Need to Change the Kernel Parameter of Your System.Android OS and devices have many variations, it's not possible to test in all platforms. If your installation does not work, please just uninstall it, don't give any bad comments nor low ranks. Many people mobiles just work while yours does not.If you like this application, or want to donate to the author, or want AD-free version, please visit https://play.google.com/store/apps/details?id=com.RombieSoft.adj_sd_speed_proLatest PRO version provides more settings for IO scheduler, fifo_batch, nr_requests.This app can adjust the SD card parameter "read_ahead_kb" in your Android Linux kernel setting. By setting the attribute, your mobile device and SD card read/write might gain better performance. The buffered read performance is highly correlated with running Apps on SD, browsing photo albums, etc. The write performance is not directly controlled by this attribute. By enlarging read buffer with reducing read action to SD, write command can be done more quickly and efficiently without being interrupted by multiple separate SD read command. On the mobile device equipped with less memory space, it's recommended not to set the buffer size larger than 1024KB. The larger buffer size is good but it might affect the available memory space used by other buffers and normal Apps. It could result in bad performance due to Android needs to kill inactive Apps and recovery memory frequently.Also, you can set the App option to automatically enlarge the default system buffer on EVERY boot.This app also has built-in performance testing feature. This does not actually reflect the real RAW SD read/write speed, but highly relative to your normal phone and Android usage because Linux OS has system buffer for file IO.**NOTE** Android is multi-tasking OS and Java-like VM. Due to lack of REAL-TIME operation (and impossible to lock your phone to do real time jobs), the performance testing results might be affected by many factors, such as background tasks, App managers, Dalvik VM garbage collections, Android System and Google Services, and etc. If the testing result looks not accurate, please quit/kill some applications running in the background or accessing to SD, and perform multiple run to see the best one.This FREE version only has 512KB, 1024KB, 2048KB for you to set the SD read_ahead_kb size. Also the performance testing size is also limited to 2048KB and below only.