I've replaced a motherboard and a CPU but still I've been suffered by a high frequency freeze problem.

Especially a freeze occurs as I use vscode. In sometime, just opened the vscode caused a freeze.

So the memory and the ssd are two of the remnants components which is(are) cause(s) a freeze.

Due to the economic problem, I can only replace one of memory and ssd.

Which should I replace(or attach a memory )?