you do not have that much internal storage due to the fact you are using the Razr Hd which only has 16g , 12 which all you can use, the maxx hd has 32g internal
This phone, the HD, non rooted, usually has about on average between 100 and 200 megs free, there are some apps that can help it but lag is an issue with this phone, no way of really getting around it.
It's only been recently that my RAZR MAXX HD has starting lagging when loading the home screen app icons or opening the app drawer. My RAM available is hovering around 150mb most of the time. What I don't get is it shows I am using like 750mb, yet if you add up the "running apps" it's like 300mb.
Does that mean there are hidden apps using RAM?
Just clear the Data Partition once every 2 weeks, you will be fine:
1. With the phone powered off, press the VOL UP + VOL DOWN KEY together + POWER KEY .
2. The device will display different BOOT OPTIONS
3. Use the VOL DOWN Key to SCROLL to Recovery and VOL UP Key to SELECT
Tip: If the device reboots, you may have waited to long to make a selection, you will need to begin the process again.
4. The device will display the Motorola logo and then the Android in distress ( logo with Exclamation mark)
5. Press and hold the VOL DOWN key, then tap and release the VOL UP key.
Tip: You can try this step, holding the phone in landscape. If you are stuck on step 5, try a force reboot by pressing the power Key and Vol Down key, and start the process again.
6. The device will display additional menu options (Text will appear in BLUE)
7. Use the VOL DOWN Key to scroll to wipe cache partition and the POWER Key to SELECT this option.
8. The device will then perform the partition wipe
9. Once the Formatting is complete, press the POWER key to confirm a REBOOT
11. The device will reboot and start the normal power up sequence .