I've made another short test of Minetest 0.4.13 MSVC 64 bit on Win 7.
My purpose was to compare stutter while mapgen v6 was working on freshly created map and when it was idle on the same place (all nearby blocks generated - idle mapgen), without restarts.
How it was done, MT started fresh map, type /sethome and start walking straight to North, pressing space at obstacles and in water, avoiding tree one block left, dropping down into cave at nearly 60 sec, after this run I did flyover of the route, observed if most nearby blocks are loaded, after that I started from home position and did the same route (this time mapgen was idle). Data was recorded with FRAPS and processed in Excel. All big IO hungry task programs were disabled at the moment of testing.
In general it looks like this (from fastest frames to slowest):
30 % of all fastest frames when mpv6g is working has good performance (~100 FPS)
however, after that frame rendering slow downs to 50 FPS (20% of all frames)
50 % of all fastest frames when mpv6g is idle has good performance (~100 FPS)
after that it is equal with working mapgen in range from 50 to 80 % of frames.
At 80 % performance starts to diverge
when mpv6g is working 8% of slowest frames are below playability limit (24 FPS)
when mpv6g is idle only 1% of frames are below 24 FPS
and big stutters part:
when mpv6g is working - 1.6% of frames will be lower then 10 FPS
when mpv6g is idle - 0.7% of frames will be lower then 10 FPS
when mpv6g is working - 0.2% of frames are extremely low performance (<7 FPS)
when mpv6g is idle - 0.1% of frames are extremely low performance (<11 FPS)
I hope you will understand it somehow. In general, when mapgen is working Minetest 0.4.13 will be slower half of the time (or much slower 20 % of the time). When mapgen is idle, 99% of all frames will be playable (>24FPS), while under mapgen load it is nearly 92% of all frames (or 8% of frames with unacceptable performance)
Interesting link about stutters: https://developer.nvidia.com/content/an ... centiles-0
Also, if above graphs are not convincing (or hard to understand), just look below! You will see clearly average FPS and actual stutter (Y is rendering time in ms, X - is # of frames):
^^^ Just look at those spikes, lots of spikes, that actual stutter that ruins playability. TOO MUCH actually.
When mapgen is idle game is much more stutter free as you can see on a graph above (just 20 noticable stutter events in 60 sec, that's like 1 stutt every 3 sec :D)