>>940287>Two sticks are fasterWrong. Four ranks at the same clockspeed are faster than two, not slower, because of rank interleaving
>put less strain on the memory controllerWrong, you can't "put strain on the memory controller", it's not an arc welder or an electric train.
>and consume less power.This is true, these 5W are probably really important.
>>940262Sticks aren't important, what you need to care about is ranks: sets of chips that work together as a team. Multiple sticks means multiple ranks by necessity, but you can also get multiple ranks on one stick depending on how it's laid out. Multiple ranks using the same data line means the data line becomes noisier*, and achieving high clockspeeds becomes harder.
If you have more than one rank on a channel, a modern (Skylake or later) CPU can perform rank interleaving: while the current rank is transferring and using only the data lines, it uses the control lines to run the RAS/CAS procedure on the next rank so it's hot to trot the moment the first rank has finished. This is only helpful for non-linear reads, as the RAM does this itself anyway if you read sequentially, but only the simplest of workloads read sequentially.
tl;dr, the most important factors are, in order:
- actual amount of RAM
- achievable clock speed**
- dual/triple/quad channel***
- channel interleaving
- rank interleaving
* but bear in mind that having four sockets means the data line for the socket is there anyway, whether you put something in it or not. Hardcore overclocking boards will only have one socket on each channel for this reason.
** AMD in particular is very dependent on fast RAM. Intel has a bunch of tricks to get the RAM utilisation up and fetch things ahead of time
*** you would expect this to be a lot higher, but it's not. Modern CPUs prefetch very intelligently (AMD not so much), so having 50% less memory bandwidth only translates to 10-20% less performance, and in some games you won't even notice.
