Bios performance modes

ChuckP509

Honorable
Nov 22, 2012
9
0
10,510
I'm new to these Forums so I apologize in advance for any inconveniences.
I recently built my own computer for the first time. I wanted to build it so that it was not extremely costly but so that I could play some of the games I've been wanting to get.
Motherboard: P8Z77-M
CPU: BX80637i53330
Power: RD500-2DB
GPU: 01G-P3-N988-TR
Memory: PXD38G2400C11K
Windows 7 x64 professional

So I've been playing on it for about 2 weeks now and everything has been fine. I remembered that upon entering the BIOS you have the option to select performance modes such as Power saving mode, Normal mode, Optimal mode. It has been set on normal this entire time until I decided to see what would happen with optimal mode. After setting it to optimal mode and restarting the Dram light lit up and the machine powered up and down multiple times before finally staying on except with no screen. I read that switching the jumpers might reset the bios so I did that with no luck. Then I tried the cmos battery out for a while and back in and nothing happened. Finally I Took the memory stick and switched places and finally I got the bios screen where I set it back to normal and I am up and running again.
My question is: why did the optimal option do this? Is the memory not compatible with this or do I need to update my bios? I'm pretty new at building and tweaking computers.
 

ChuckP509

Honorable
Nov 22, 2012
9
0
10,510
Also I want to know that If I upgraded to a better video card, would games run a lot better? I installed Guild Wars 2 and I have to run it on pretty much all low to medium settings.