system dont feel right an upgrad my help?

[Dave0w]

speck
CPU: I3 2120 @ stock
Board: P8z68-v
Ram: 8gb 4x XMS3 @ 1600mhz
GPU: on board
HDD: WD carver black 500gb


Right when i am useing the system it feel as if there is lag all the time, there is lock ups one a day at random, i think may be down to a hot room and running the iGPU, or it could be HDD lag as the drive is getting old but all tests sat the system is fine.

so i am thinking of upgrading some parts to try and sort the problems out any input on where to start?

also the system is not used for gaming but i think added a cheap GPU will help? what good right now in the low end stage

 

[Dave0w]

asus say my mother board will support faster ram but only via OC dose this mean i have to OC the CPU to get the ram speed's or is there an option to just OC ram?

asus say (but i have no clue lol)
4 x DIMM, Max. 32GB, DDR3 2200(O.C.)/2133(O.C.)/1866(O.C.)/1600/1333/1066 MHz Non-ECC, Un-buffered Memory
Dual Channel Memory Architecture
Supports Intel® Extreme Memory Profile (XMP)
* Hyper DIMM support is subject to the physical characteristics of individual CPUs.
* Refer to www.asus.com or user manual for the Memory QVL (Qualified Vendors Lists).
* Due to CPU behavior, DDR3 2200/2000/1800 MHz memory module will run at DDR3 2133/1866/1600 MHz frequency as default.

 

[Dave0w]

going from 4x2gb @ 1600 mhz, would there much improvement with 2x4gb @ 2133mhz

thanks for the advice on the ram Lukie, but the GFX are a little under what i was wanting i was aiming at around 80 to 100 mark i may got for a 77XX card for the free games
http://www.overclockers.co.uk/showproduct.php?prodid=GX-184-MS&groupid=701&catid=56&subcat=1699
for the price is this worth getting or would i be best with a 7750 @ £65?
http://www.overclockers.co.uk/showproduct.php?prodid=GX-183-MS&groupid=701&catid=56&subcat=1699
remember system is not for gaming but i want a card that will do HD-DVD and so on for a few years to come