Choosing between Mega and Arduino 101?

Hey guys, I’m doing an IoT project that requires me to load an html file and control the Arduino through a webpage via ethernet. I got pretty far with my W5500 ethernet shield and arduino uno, but now it seems that my uno runs out of SRAM despite my attempts to optimize code, so I’m looking to either buy a 101 or a Mega. I need 3 PWM pins for a Stepper and I need another pin for a servo, and I also need to connect my ethernet shield. For my purposes it seems that the 101 would be best because it has more memory and SRAM, but when i read the documentation for the ethernet shield, it says pin 4 can be used for SD card access for Uno and Mega. Does this mean I can’t access the SD card with the 101? Also the servo library says it disables analogwrite()(PWM) on pin 9, does this mean I can’t use it for stepper control?

Since your user name says "Newbie" I recommend against Arduino 101. Intel has done a terrible job of support for all their Arduino boards. There are very few people using those boards so you will not find much 101 specific help. Some libraries are specifically written for the AVR architecture of the Uno, Mega, etc. and will not work with the 101. Basically it is only a good choice for advanced users who want to tinker around with the ARC32 architecture and don't mind the lack of official and community support. Even then there are so many other more popular options I can't imagine why anyone would use that board.

Can't really help you with the actual question. Pin D4 is available on the 101 as far as I can see, so the SD card should work as on the Uno. Regarding the PWM. I don't know.

But if you post your code (place code between
** **[code]** **
and
** **[/code]** **
please), somebody might want to look over it and advise if RAM usage can be improved.