Caching when not turned on?

I have a fresh OS/apps install and a sparkling new 4 disk RAID. I haven't really configured Resolve since v10 and I think I've clearly forgotten something.

The first disk listed in my preferences list will be where caches are stored. Correct? Does this pertain ONLY to render caches you turn on? Like user or smart?

The first time I load media into a project, go to the timeline, I get poor playback. 2.5 or 4k raw files play back at 10-15 fps.

Once the clip has been played once, I get full speed, buttery smooth, real time playback. However, I don't have render caching turned on. It's off, but it certainly feels like Resolve has cached that clip somehow.

If I create a new project and import 2 clips I haven't imported before and one clip I have in a previous project...the first two clips will repeat the pattern, however that third clip still plays like butter on the first go. Even though I'm in a completely new project...and render caching is still off.

So I'm trying to figure out:

A) why the first playback of a clip is so poor (my GPU use is also very choppy on first play and solid on subsequent plays)
B) is Resolve caching the clip somehow?
C) if so, where is that cache?

My new RAID is giving me 580/560 read/write. I'm running a Titan 6GB. (nvidia 350.12) i7 990X, 24GB ram, Sandisk Extreme 480 SSD for OS/Apps. OCZ 120 SSD for previews/caches. Running windows 7 pro 64bit and Resolve 11.3 (not lite)

Samart cache i think is on by default: you play ans a clip that does not get realtime will be silently cached. Next time you have it in realtime.

I usually turn on [user] cache, so i do not get the effect, but I think that that is what it is going on.

Thanks Walter

That would make sense, but render cache is set to none.

Thanks Walter

That would make sense, but render cache is set to none.

I assume that cache "none" still have "smart cache" on by default unless you set to "user"

At least this is my understanding...

I assume that cache "none" still have "smart cache" on by default unless you set to "user"

Render cache, at least as it appears on my install of 11.3 has three options: none, smart, and user. As far as I've experienced it, none really does mean none. It doesn't render cache anything on my machine when I set it to none. When I set it to smart, it decides what to cache. And when it's set to user, I choose which nodes get cached.

It's worked great except for lately it has been caching many of my cross dissolves or fades to black as simply 100% black frames and so I haven't been able to use the render cache feature. I'm not sure if it's a bug or an issue with just system though I've seen a few posts by other people who have run into the same issue.