I did this one at 800x800 by mistake but I'm posting it anyway because it looks so impressive. this time it's 5 toruses rotated 72 degrees to each other with RD=8 and RPP=256. The center details are much too fine so I'm going to redo it at RD=6 and at 1024x1024. This render took 3 hours so I'm estimating the new one at around 5 hours. Then again, with the lower RD setting it may take 4 hours. It won't be as bright either.
One more thing, if you examine the very center of this image you will see a blue tint. This is because I mistakenly left the default blue sky dome color. The new one will be full black.