The folder winsxs is large and continues to grow as more updates are made.
There are Win8.1 function automatically cleans 30 days old updates but sometimes you need to clear to get the disk space, especially if you have the system on an SSD.
To see the actual size of this folder, run a command as Administrator.
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
When you see portrayed market what Windows reports the size of the folder and the real size. Clear with these three commands each of the first takes a long time.
DISM.exe /online /Cleanup-Image /StartComponentCleanup DISM.exe /online /Cleanup-Image /StartComponentCleanup /ResetBase DISM.exe /online /Cleanup-Image /SPSuperseded
After the new installation of Windows 8.1 and updates of all KB so the folder winsxs 15 GB. After cleaning 4,7 GB and it may be worthwhile if space is tight.