I run sabnzbd/sonarr/PLEX server.  I noticed a performance increase going from 4 gig to 8 gig.  Im not sure if its worth spending the $90 to go from 8 to 16 gig since its basically just me loading server.  Its not like there are 4-8 people hitting the server at once.

Old computer axiom ... you can NEVER have "too much memory";  "too much storage";  or "too fast a processor"  8)

 

However, realistically 8GB is almost certainly plenty since you're not processing multiple streams.

 

Another consideration:  On systems that use unbuffered RAM (most UnRAID servers are in this category), the memory will be more reliable if you don't install more than 2 modules (one/channel).    When you go beyond 2 modules, the bus loading on the address and data buses causes significant waveform distortion that can make your memory subsystem much more susceptible to random errors.    So if you're considering adding 2 more 4GB modules, I'd definitely just stay with 8GB.    If you want to go to 16GB, it's best (if your system supports 8GB modules) to use a pair of 8GB modules.

 

Old computer axiom ... you can NEVER have "too much memory";  "too much storage";  or "too fast a processor"  8)

 

However, realistically 8GB is almost certainly plenty since you're not processing multiple streams.

 

Another consideration:  On systems that use unbuffered RAM (most UnRAID servers are in this category), the memory will be more reliable if you don't install more than 2 modules (one/channel).    When you go beyond 2 modules, the bus loading on the address and data buses causes significant waveform distortion that can make your memory subsystem much more susceptible to random errors.    So if you're considering adding 2 more 4GB modules, I'd definitely just stay with 8GB.    If you want to go to 16GB, it's best (if your system supports 8GB modules) to use a pair of 8GB modules.

 

Im not buffered, but i am part of the ECC master race.  I am currently using 1 8 gig stick.

In that case, I'd add another 8GB module.

 

Not so much because you really need the extra 8GB ... but because your system will then run in dual channel mode, which doubles the bandwidth for memory transfers [Yielding about a 10-15% increase in overall memory performance].

 

For me it's simple - if I'm not swapping, I have enough RAM. But, I agree with garycase - you can never have too much...