User blog comment:ShizaRiku/Getting Shaders to work in Middle Earth/@comment-69.242.54.218-20170117145049/@comment-30861465-20170117153605

You would be supprised at what optifine can do. It also depends on your regular video settings, shader setting, and what shaders you are using. There are many "lite" shader mods available. If you are having  trouble  rendering your shadows try swtiching from unlimited  frame rate  to a limited one. A good value is above your screens refresh rate as this will allow to display the maximum that your screen can display and account for fram drops due to loading. By limiting your frame rate you are essentially telling it to not make additional frames that would otherwise have been made by the unlimited option thus giving it more room to render the shaders or load chunks. Also lowering your shadow resolution in the shader options can help and whatever else is there that you can turn on or off to save ram space. Lowering from fancy settings to fast on your options can help and lowering render distences to around 10 as that is what most server have. If you have more than 2 cpu cores turn on multi-core chunk loading as this will take advantage of more of your computers power than if it were off. On the  multi-core chunk loading if you experince chunk flickering turn off threaded optimization in your gpu's system setings as this cuase conflics with  optifine's  multi-core chunk loading. Check to see if your card supports OpenGL as turing on advance  OpenGL will make you gram run at sanic speeds. Look to see if your gpu has high performace settings as thouse are somtimes tuned off or "power saving mode". Fastcraft is incompatiable with shaders however I would look at fps+ if you are still having troubles.