What photo viewer can quickly display large photos (40+MP) on a 4k monitor?

Question

Software and Internet Services

There's a Sony A7R2 that takes 42MP photos and there's a 4k TV on which it all looks and sorts.
Previously (while there was an old 12MP camera), I used Google Picasa to view photos, it allows you to quickly scroll through the photos, but when it goes to the next one, it first shows a very poor preview and after a couple of seconds the photo is in normal resolution (with 12mp it was about 300ms, which quite adequate).
I tried Capture One, everything is quite sad when you scroll through the pictures, the delay is 1-2 seconds.
I tried a couple more softins from the Internet (fastphotoviewer and something else), the result is similar.
The question is, is there a normal viewer that caches everything beautifully and loads pictures in advance?
The problem is not in the hardware. Photos are stored on SSD (Samsung Evo 850 512), CPU 2500K, 16Gb RAM.
In a few hours yesterday, I sketched a script in python+opengl+opensv that loads photos into memory in advance, makes a 4k preview, merges it into video memory and then scrolls directly on the video card. There are no delays, you can even watch a movie frame by frame. Those. The jpeg decoder takes 1-2 seconds to decode (1 thread per cpu) the original jpeg, but when everything is already in memory, everything happens instantly. That's why I expect that real viewers should preload everything beautifully in advance so that I don't notice these brakes.