Pocket Pc 2003 File Access Faster Than Windows Mobile 5,6,7 A very valuable information for the Windows Mobile developers

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I recently did a detailed research on the file systems of the windows mobile.The windows mobile platform was initially called the Pocket PC platform and later called the Windows Mobile platform from version Windows Mobile 5 onwards.Till Pocket PC there was no default permanent storage for the windows mobile devices. So whenever you do a cold boot of your device, all your data will vanish away and so you have to be careful not to drain all your battery in your Pocket PC powered mobile device. This shows that the windows mobile till Pocket PC 2003 had only a RAM memory and did not have any Flash ROM for storage. This decision was made by Microsoft keeping in mind that the mobile devices will be always required to be ON like the mobile phones we use today. So in this case the RAM(Random Access Memory) itself is used for both the Storage Space(user files and data - equivalent to Hard Disk in todays computer) and Program space(The memory that is used by the programs - equivalent to RAM in today's computer). Then later Microsoft decided to have a permanent flash file ROM storage for storing the Operating System and for Storage Space and so from Windows Mobile 5 onwards by default all mobile device had some ROM storage also. And from Windows Mobile 5 onwards the RAM can never be shared and used for storage space. So application developers who used files to store and read data have to address this issue. When there are frequent access to the file from the application, the same application runs slower in the Windows Mobile 5 or later than the Pocket PC 2003 device because in Pocket PC the files are stored in the storage space which is the RAM and in windows Mobile the files are stored in the Flash ROM memory. Since RAM devices are faster than Flash ROM, the application runs almost 10-20 times faster in windows mobile 5 or later than the Pocket PC 2003 which is an older version :-).There were two major reasons for switch from RAM to ROM for storage space1. RAM is a volatile memory and will get cleared when the power is OFF2. power consumption for RAM is dependent on the RAM size while the consumption by Flash ROM is independent of the memory size.point 2 means that for eg :- power for 64 MB RAM is twice that of 32 MB RAM whereas the power for 32 MB FLash ROM and 64 MB Flash ROM is the same.So application developers take this point when you choose a platform for your windows mobile solution.