Novice wanting to upgrade game rig

[mooresville kid]

I have a rig i built three yrs ago and have three hundred whole dollas to spend on upgrading. The only thing i play on this rig is online sim racing. here are my present components;
ASUS M4A785TD-V-EVO motherboard socket AM3
AMD PHENOM II X2 3.20 GHZ BLACK EDITION
4-MB RAM 1333 MHZ CORSAIR
750 WATT PS
XFX 6770 ATI 1G 128-BIT
WINDOWS 7 32-BIT OS
HOOKED UP TO A 32 INCH LCD RUNNING IN NATIVE RESOLUTION 1080P
Right now I run at 30-60 FPS with graphics set around 80% not sure which way to go with what little coin i have to spend. I found a combo deal at newegg with a PHENOM II X4 3.40 GHZ and an XFX 7870 256 bit for 275.00, my MB requires a 64 bit OS to run over 4G of ram, and i do not know how to overclock. ANY input would be greatly appreciated.

 

[stickg1]

I have a rig i built three yrs ago and have three hundred whole dollas to spend on upgrading. The only thing i play on this rig is online sim racing. here are my present components;
ASUS M4A785TD-V-EVO motherboard socket AM3
AMD PHENOM II X2 3.20 GHZ BLACK EDITION
4-MB RAM 1333 MHZ CORSAIR
750 WATT PS
XFX 6770 ATI 1G 128-BIT
WINDOWS 7 32-BIT OS
HOOKED UP TO A 32 INCH LCD RUNNING IN NATIVE RESOLUTION 1080P
Right now I run at 30-60 FPS with graphics set around 80% not sure which way to go with what little coin i have to spend. I found a combo deal at newegg with a PHENOM II X4 3.40 GHZ and an XFX 7870 256 bit for 275.00, my MB requires a 64 bit OS to run over 4G of ram, and i do not know how to overclock. ANY input would be greatly appreciated.

That's a good deal. It's not so much a motherboard limitation on the RAM, it's just Win7 32bit will only utilize slightly more than 3GB RAM. It can't use the full 4GB or more. I think the 3.25GB RAM or whatever it tells you in "System" will be fine for your usage. I would get that quad core CPU and the 7870. The 7870 is typically $275 by itself and you get a $100 CPU for free. So snag that up while you can and later on down the road you can upgrade your OS and RAM.