Uh... Summary says it all.
My graphics card is: Mobile Intel(R) 4 Series Express Chipset Family, and my processor is: Celeron(R) Dual-Core CPU, T3500 @ 2.10GHz ~2.1GHz
Environment
OS Is Windows 7 Home premium, 64-bit (6.1, build 7601). Java is Version 8 Update 5 (build 1.8.0_05-b13)
That is intended.
Transparent textures require the gpu to do a lot more work.
So by switching to fast from fancy, it will downgrade to be drawing fewer transparent textures in order to lighten the load.