Some Overviewer Rending data collected...

renderStats.json

GeneralData:
All renders are --forcerender
2.4GHz, 2Gb RAM, WinXP SP2
Start time is the time the 1st 0/X (0.0%) tiles completed time stamp.
Smoothing option adds approx 30% more time per render.
Each render checked for consistancy after render to ensure completness.
All time numbers rounded to closes hole.
*Granted: the nether is much more complex than the end.*

***

ControlRenders:
world:world_the_end;
size_multiplier: 1,

world_tiles: 287,
{
	Test: 1, [start: 13:55:08;end: 13:55:44;total_time: 36;render_type: normal];
	Test: 2, [start: 15:53:07;end: 15:53:48;total_time: 41;render_type: lighting];
	Test: 3, [start: 15:54:05;end: 15:55:45;total_time: 40;render_type: night];
	Test: 4, [start: 13:59:23;end: 14:00:04;total_time: 37;render_type: smooth-lighting];
	Test: 5, [start: 14:01:47;end: 14:03:02;total_time: 75;render_type: normal + smooth-lighting];
	Test: 6, [start: 14:06:10;end: 14:08:05;total_time: 115;render_type: normal + smooth-lighting + smooth-night];
}

average: time: 37.57: time_per_tile: 0.125s;tiles_per_sec 7.97

***

ExperiementalRenders:
Est_times: ControlRenders->Test: ID->total_time * size_multipler;
world: world_the_nether;
size_multiplier: 6.75,

world_tiles: 1938,
{
	Test: 1, [start: 14:12:24;end: 14:19:43;total_time: 379;est_time: 240;render_type: normal];
	Test: 2, [start: 15:58:00;end: 16:06:16;total_time: 496;est_time: 277;render_type: lighting];
	Test: 3, [start: 16:15:33;end: 16:23:49;total_time: 496;est_time: 270;render_type: night];
	Test: 4, [start: 14:24:42;end: 14:36:37;total_time: 725;est_time: 254;render_type: smooth-lighting];
	Test: 5, [start: 14:40:44;end: 15:00:25;total_time: 979;est_time: 506;render_type: normal + smooth-lighting];
	Test: 6, [start: 15:10:13;end: 15:41:53;total_time: 1840;est_time: 776;render_type: normal + smooth-lighting + smooth-night];
}

***
Comparison:
Delta: in seconds;
{
	normal:343
	lighting:455
	night:456
	smooth-lighting:688
	smooth-night:1725
}