Possible Motherboard issue

[ryuji_chan]

Hello everyone. I recently bought an ECS H77H2-M3 motherboard, alongside a Zotac GTX 650ti 1GB 128BIT DDR5, 2 4gb HyperX Fury 1600Mhz RAMs, 500GB WD HDD and a 500W power supply. The issue here is that, whenever the GPU is connected, booting takes about 3-5 minutes. The bios screen freezes, as I can't access the BIOS menu, and the computer beeps 3 times, in an interval of around 1 minute each. After that, windows loads and everything fine. What could be causing this issue? If I take off the GPU the computer starts just fine, I can access the BIOS and everything works alright.
I hope you can help me figure out what is the problem thanks!