Render bug

This .upr runs in a few seconds at 640X360.
On 6.02 it takes about 3 hours at 19200X10800 (no AA).
On 4.03 it takes about 10 mins at 19200X10800 (no AA).

dot25 {
fractal:
  title="dot25" width=640 height=360 layers=1
  credits=""
layer:
  caption="Background" opacity=100 method=multipass
mapping:
  center=0/0 magn=1.3
formula:
  maxiter=1000000000 filename="Standard.ufm" entry="FastJulia"
  p_seed=.25/0 p_bailout=4.0
inside:
  transfer=none
outside:
  density=0.2 transfer=log filename="Standard.ucl" entry="Smooth"
  p_power=2/0 p_bailout=4
gradient:
  smooth=yes index=0 color=15459814 index=99 color=2726861 index=200
  color=76 index=300 color=66047
opacity:
  smooth=no index=0 opacity=255
}

I tried this at half size, 9600X5400, without anti-aliasing. The render took about 7 1/4 minutes. This scales to 29 minutes at 19200X10800.

I don't have UF4 any more, but I re-installed 5.04 and started rendering at half size. It was going to take well over an hour, so I stopped it after a few minutes.

Interesting.

I did the same test as "physicist".
Same result with UF 6.02 - 9600*5400 - AA off - iterations 250

3/08/2020 20:40:40: Starting job dot25.
3/08/2020 20:40:40: Anti-aliasing off.
3/08/2020 20:40:40: Motion blur off.
3/08/2020 20:40:40: Rendering in PNG format.
3/08/2020 20:40:40: Calculating dot25 in D:\Data\Ultrafractal_601\Test\202008.upr.
3/08/2020 20:48:02: Finished calculation. Time: 0:07:21.60.
3/08/2020 20:48:02: Saving to D:\Data\Ultrafractal_601\Test\dot25.png.
3/08/2020 20:48:05: Job finished.