9600s Acting weird please help

Hi guys i have two 9600s GT , and i get an issuie in game most games that when they arnt to stressed they do fine but when they start having to kick it up a notch my speakers begin to screech just a tad during games like BSP and ETW. I dont understand why becuase it use to didnt do that with one card it would just lag like hell if it couldnt handel it but i know two 9600 GTs SLIed can handel ETW on ULTRA with 4x or at least High settings. I dont understand what is happening please help me i would really like to take advantage of the situation.

Intel Pentium D 830
Intel Pentium D CPU 300 GHZ
Model (0gc375) DELL XPS 600
PCI Express x16 (two slots)
(CHIPSET)nforce4 SLI Intel Edition
(RAM) DDR2 4 GIGS
(Video Cards) 9600s GT OC (BFG TECHNOLOGIES manufactured both) but one was blue and one is green.
My monitor is a 30 inch VIZIO HD (1920 x 1200) res wide screen.
I am running windows XP 32 bit (Service Pack 3.5)

I dont even know if the SLIs are actually working in games becuase i get the samer performance out of the game with just one video card working , i am very confused with the situation , i just dont know what to do like if i need to plug in the cords in the back (the white cord to 1 video card and the blue cord to another you know i just dont know please help me guys)

Can you put that in lame man terms please sir.

dn't worry bro, I'm a noob too and I asked a lot of dumber questions than you did. That's why there are forums like this to clear our doubts. What apache_lives means by "your CPU bottlenecking your performance" is that the because of the old CPU and its performance limitations the graphics cards and other components are not being utilized to their capability. So if you get a better CPU, it can utilize the GPU's to their full extent, and that the CPU is the loose end in your system, at least when it comes to gaming. @pros, correct me if I'm wrong coz I too got hold of the hardware tech very recently.

That as much sums it up. You got it perfectly alright.

To sum up, I would not find anybody recommending a branded machine over the one that we can build by ourselves, for the simple reason that the branded systems cost a fortune over similar/better configured systems that are self built. Since you've got a friend helping you out, it's very much out of the point to think of buying a branded system. But are you going for a laptop or a desktop? As for the desktop branded system's pretty much out of the question and as for laptops I can't say as I myself don't own a lappy, though the configurations for branded laptops are also improving by the day.