In general the more common an hardware info app is the more likely it is that the hardware faker have integrated a patch to let a system info app display wrong values.

Therefore the best way to identify fake hardware is not to use an app at all. Using a Linux command-line program e.g. executed via adb identifying fake values or values that do not match if more likely. To do so I would recommend to copy a (renamed) busybox binary via adb to the phone and then use it to check free/total RAM and existing partitions and their size.

In general the more common an hardware info app is the more likely it is that the hardware faker have integrated a patch to let a system info app display wrong values.

Therefore the best way to identify fake hardware is not to use an app at all. Using a Linux command-line program e.g. executed via adb identifying fake values or values that do not match if more likely. To do so I would recommend to copy a (renamed) busybox binary via adb:

1. rename it to something different like mybinary
2. push it to the phone adb push <mybinary> /sdcard
3. start adb shell
4. copy the binary it to a path where you can execute it: cp /sdcard/<mybinary> /data/local/tmp/
5. make it executable chmod u+x /data/local/tmp/<mybinary>

Now you are ready to use it..eg. to check the physical RAM:

/data/local/tmp/<mybinary> free
            total       used       free     shared    buffers     cached
Mem:       5727792    5528296     199496      67020       1712    2170428
-/+ buffers/cache:    3356156    2371636
Swap:      2097148    1737312     359836

In this example the total memory of the phone is 6GB minus the size used by the GPU. So we end up here with 5727792 total memory = 5.4GB max RAM

To print disk size you can use

/data/local/tmp/<mybinary> df -h /sdcard
Filesystem                Size      Used Available Use% Mounted on
/dev/fuse               109.6G     17.9G     91.5G  16% /storage/emulated

It shows the user data partition size and usage. The used phone has 128GB flash memory. The user data partition is smaller as the remaining space is occupied by the system partition(s) and other partitions.