Differences render cache and render cache color output

Hi my friends. I know that my classic workstation HP Z820 with an old Nividia Quadro K4000 isn't the right Nvidia cards to works on Davinci, but i can't find on market a new RTX card. Anyway, i've got an headache when i make render.

i've got my timeline UHD 25fps with some clips from my Eva1. My Timeline proxy mode is Off. i haven't any optimized media or proxy files. I start to do a color grading using color space transform and some Open FX as Color Compressor node. i don't use noise reduction. only a little blur radius to take a little bit more detail.

If i use render cache smart, my clips comes with a blu render bar. If i hit play, the timeline works very choppy (6.5fps with a red dot). if i optimize that clip, the playback still works choppy.

If i do right click on that clip/clips and i force to do render cache color output, everything works perfectly!

Please somebody can you tell me what exactly smart render cache render inside my color nodes? if i open my color page, i see my CST and OFX nodes rendered blue also with smart cache render enabled.

many thanks!!!

EDIT: i found also that if i force to use only render cache color output, the render weighs much less on my ssd than the smart render LOL.....

Smart only applies to when something is rendered. Resolve makes that decision for you. User places that decision in your hands.

There are two Caches, Color and Fusion. It's possible to only render one, leaving the other to its best real time efforts, which may fail.

That help?

Smart only applies to when something is rendered. Resolve makes that decision for you. User places that decision in your hands.

There are two Caches, Color and Fusion. It's possible to only render one, leaving the other to its best real time efforts, which may fail.

That help?

Mmm yes and No.. I mean, I know how it works smart or user render but I don't understand why the same clip graded, if it's cached via smart, its playback works choppy instead works perfectly, if I force the render cache color output in user render cache mode..

Because the Cache under Smart is for the Fusion effects, not the Color nodes.

Because the Cache under Smart is for the Fusion effects, not the Color nodes.

Mmm ok, so the Open FX that you can use in color page inside nodes, are inside the fusion effect's family? That's strange because inside the Open fx there are also color management like color space transform etc..

It may depend on the effect used. I definitely haven't tested and use them all.

In fact, I tend not use use any effects on Color, intentionally doing them all in Fusion.