I’ve been happily running 5.0rc8 on a:

 

X8SIL-F-O / i3 540 / 4x2GB Kinston 1333 MHz ECC / 2x AOC-SASLP-MV8

 

rig problem-free, and have recently been playing with the Plex plugin, streaming both over LAN (a mix of Cat5e/powerline) and WAN (12mbit upload).

 

Most of my files are ~10-15 GB x264 high profile L4.1 and I’m able to transcode two of them (barely) before they start fighting for frames.

 

So…time for more core. The easiest thing would be to throw in an i7 860, although I’m reading mixed things on compatibility with the board, not to mention the high price for a dated CPU. What kind of improvement would I stand to gain from just switching from i3 540 to i7 860?

 

I’m also looking at switching to a X9SCM-F-O / E3-1230 combo, keeping the RAM and sata cards, which I think is possible. How much benefit would I stand to gain? Able to transcode to three/four clients?

 

Related questions, if anybody can answer:

 

1) After tinkering with the plex settings I’m wondering if trandcoding from a high bitrate to a medium bitrate vs transcoding to a low bitrate - is it the same work for the CPU? More tasking? Less tasking?

 

2) I also thought about installing plex server on my 2600K rig, mounting the unraid folders, and presenting clients with a second (mirrored) library. Would that work?

Regarding your 1st question, I honestly do not know. It is hard to tell without knowing the inner workings of ffmpeg.

 

By design, plex always maxes out the cpu when transcoding. It tries to transcode as much as possible in as little time as possible to reduce/avoid buffering in the long run. So when you test, the result is that it either works, or not. You don't know how much it is really taxing the cpu, and you also do not know how much more room you have before maxing out.

 

On my unraid rig, athlon ii x2 4450e, if I transcode one stream from a 4-8GB 720p rip to a 3Mbit/s stream, cpu is maxed out, and it plays fine.

If I do two clients streaming at once with the above conditions, again, the cpu is maxed out but both streams play just fine. I haven't tested more clients at once, but I guess the only way to determine the max is by testing the actual hardware.

 

Or you can ask on plex forums because I am sure people there test this with different hardware.