Cpu holding back my system?

[c61ll]

I Have been playing around with the settings on mafia 2 and after the running the benchmark at various settings i do not get much difference in framerate.
I checked and found out that my GPU was running around 50-55% no higher.
My CPU was running at 100% on both cores a lot of the time.
Does this mean its time to get an i5 2500k?
Will there be much of a difference in framerate?
Thanks

 

[pob9]

time for quad core at least. if ur low on cash a second hand q6600 wud see ya thru for a bit without having to change ur mobo + ram. but if ya can afford it yup its upgrade time

 

[c61ll]

Can i do any better than this?
Intel Core i5-2500K 3.30GHz (Sandybridge) Socket LGA1155 Processor - OEM £173.99
Asus P8P67 PRO Intel P67 (Socket 1155) DDR3 Motherboard - (Sandybridge) ** B3 REVISION **
£149.99

Corsair Vengeance 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit (CMZ8GX3M2A1600C9) £89.99

Sub Total : £344.97
Shipping cost assumes delivery to UK Mainland with:
DPD Next Day Parcel
(This can be changed during checkout) Shipping : £9.50
VAT is being charged at 20.00% VAT : £70.89
Total : £425.36

Can somebody advise a good cpu cooler for around £30 also please?
Thanks

 

[metbandit1]

i have the i5 2500k that i have OC'd to 4.4GHz and the P8P67 PRO mobo its an awesome combo.

i use a coolermaster v8 (which is slightly more than your budget) but its good. my temps go no higher than 65C with it being clocked.