[Milhouse]

So what is the debug OSD showing with 296000/382000KB?

Out of the 384MB left after the GPU takes it's 128MB, about 100MB is needed to load SYSTEM into RAM, leaving 284MB so for there to be only 66MB left suggests that XBMC uses 218MB. I'm wondering if there's any real advantage loading SYSTEM into RAM now, as to be using 218MB suggests that XBMC is fully loaded into RAM anyway doesn't it?

It's more about the whole OS being loaded into RAM than just XBMC, but it appears that devtmpfs (which is the filesystem used to load SYSTEM into RAM) is being counted as cached memory.

Here's the memory stats from top in Gotham with/without SYSTEM in RAM:

Code:

ram:   Mem: 341232K used,  40772K free, 0K shrd, 29556K buff, 260228K cached => "free" 330556K
noram: Mem: 190200K used, 191804K free, 0K shrd, 28904K buff, 108376K cached => "free" 329084K

The total "free" (maybe I should refer to it as "available" or "nonbusy") memory is approximately the same in both, but although cached memory can normally be used by processes when required I'd be surprised if the large chunk consumed by SYSTEM can be reused in such a way, which may mean these "free" memory figures are somewhat distorted whenever SYSTEM is loaded into RAM - the 100MB chunk is a component of the "free" amount in the OSD (see also System Info -> Hardware) when it's almost certainly not free.

Of course the used memory is way higher when SYSTEM is loaded into RAM, but it's open to interpretation what the true amount of free memory actually is.