Simple answer is NO, RAM will not affect speed of small files being written.
Complex answer is: DEPENDS on how much data is being written at any given time. If more than ~ 4GB? (estimate based on system taking up 4 GB) at any given moment (high I/O count) then you will benefit from the increased RAM due to the write buffer being used more intensely.
Computer Science: Data is written to the RAM while a write to disk is requested. File copy may finish, but the operating system will continue flushing data from RAM to disk.
This answer is written with Linux in mind.
A faster speed will be achieved in your case with:
- SATA III or SATA II motherboard connection to SSD, HDD won't benefit much unless it is above 7200rpm (+150MB/s speed) (this is a motherboard upgrade)
- A better CPU, thus process write I/O faster
- SSD + at least SATA II. The most inflential factor in file write speed.
As always, any upgrade will be hindered by the weakest link in the system, keep that in mind if you purchase a SSD, but have a Intel Pentium CPU running.