Views Slideshow constant cycle Is it possible to have a slideshow slide content constantly without stopping and no pause? That means it would always slide in fixed speed. I'd be using the scrollLeft effect or something like that.

It doesn't have to be Views Slideshow module, but it has to be Views displayed content which would scroll constantly from right to left.

Or should I just drop that and implement some custom javascript?
You can achieve that using the jCarousel module. I've used this module and works fine for me. 


  This module allows developers and themers to make use of the jCarousel jQuery plugin. It includes a developer API that other modules can use, as well as Views integration in the 2.0 version so that you can turn any list of content or images into a carousel.


Image from module page. 



There is another module called  Owl Carousel


  This module integrates the wonderful Owl Carousel slider built by OwlFonk. The primary module is comprised of three sub modules providing a views style, field formatter &amp; administration UI. The administration form leverages the variable module providing multilingual support out of the box.