You either need to get a low performing card like a GT 710 or you might consider removing the fan based cooling from your GTX 750 Ti and adding a silent cooling kit from Arctic. https://www.arctic.ac/uk_en/accelero-s3.html
I tried using one of the GPU coolers from Arctic years ago. It was an Accelero-something (can't remember). It was a horrible product. The mounting mechanism and heatsink was cheap junk. My video card ran hotter with it and eventually died.