I had a BIOS flash "crash" with an ASUS Striker mobo for an Intel Q6600 Kenstfield processor. So before contacting ASUS for an RMA, I spent about $15 on another BIOS chip flashed to my make, model and version BIOS.
It's just a fact of life that the more RAM in its quantity that you put in the motherboard, the longer it will take to post the BIOS initial screen.
But check some other items. For instance -- did you mistakenly leave an optical disc in the BD or DVD burner or reader? Overlooking that possibility cost me about two days in delay to my project. It was just something that simple and stupid. Before posting the BIOS, or otherwise moving on to complete boot-up at boot time, it must enumerate connected drives, and an optical disc will delay raising the OS program to post on the monitor.