can i use this pad with my CPU ryzen 9 3900x ? for your note i have custom water cooling .
if yes ,
1.how long time i can use it and can i use it many times ?
3. did will give me better performance than thermal paste?
Absolutly not. Never try to use any kind of thermalpad on a CPU. You can`t compare thermal pads and thermal grease. A thin 0,5mm thermalpad with 17 W/mk will always performe worse agains any cheap thermal greas with 3 W/mk wich is only 0,01 mm thick at the end.