There are multiple ways actually. Here are a few that come to mind:
Let it run faster by adjusting the code inside the loop accordingly
Split it into multiple loops to utilize more cores of your CPU
Buy a faster computer
Note that there is a limit to how many concurrent threads LV supports: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000PARmSAO&l=en-US
The maximum speed of a while loop is only limited by the speed of your CPU at 100% load (and of course the way your operating system shares the CPU between processes and threads). That is assuming your loop does nothing, which makes it pretty useless. Of course, if your computer has multiple cores, you can run multiple loops in parallel to make use of them.
This is contradictory to your first statement. I suppose you mean to increase the loop speed, right?
If your code is simple, it should be easy to optimize for speed or to run multiple instances concurrently if applicable.