What is process.memory giving ?

Possibly ESPRUINO software internal architecture is better than what can be expected after a first look.
I am now beginning to understand that having a local storage (SD card ) and a "huge SDRAM " amount for variables and adding to that the possibility to add or remove cached modules gives a program the ability to work as in the old fashioned overlapped memory concept.
Not the same as a virtual memory but a really effective technique on embedded system.

Assuming those SDRAM memory cost figures:

expr 20 * 5450 = 109000 100KB/192KB SDRAM 92KB free STM32F4x7, x=0,1,2
expr 20 * 8200 = 164000 164KB/256KB SDRAM 92KB free STM32F4x9, x=2,3

a lot of possibility arise for the Javascript interpreter, whose memory allocation penalty is bigger for simple variables such a int, float but not for objects or functions.
The STm32F429 can use an external 133mhz SDR SDRAM so memory cost of allocating variables will be minimized at all.

Has the capability of adding and removing cache modules been designed for such purposes or is there something more behind the scenes ?