The extra clock will of course be faster but if you want more performance an I3 or second had I5 is not all that much more expensive.
Check your mainboard has a Bios update for Ivy B too.
Get a Core i3 or Core i5 if you really want a decent upgrade. Any game which can use more two threads will give you higher framerates and lower latency figures.
On top of this,the system will be better for multi-tasking.
Are you sure HT actually make any different for gaming? I know they useful for productive tasks, but from what I saw in game benchmarks...for example Crysis 2, while a i5 with the extra physical cores have quite a bit higher frame rate than the i3 and Pentium, the frame rate difference between the Pentium and i3 is minimal - 49fps vs 52fps...so I'm more convinced that the 3fps higher on the i3 is because of the higher clock speed comparing to the Pentium in the same bench...
Also for other game benchmarks, the frame rate between the i3 and Pentium are so close most of the time, that it would be easier to believe i3 is tiny bit faster only as a result of the higher clock, rather than HT contributing/benefiting games...
Anyway, I myself have just bought a brand new G2120 for just £60, as I couldn't see that the i3 3220 having nearly extra 50% higher in price worth of extra performance for gaming and general everyday use such as web-browsing and media playback. The G2020 2.9GHz IvyBridge dual-core at just £45 was really tempting as well, but has decided to pay the £15 extra for the 200MHz higher clock speed on the G2120.
But to get back to OP question...going from a G620 to a G2120 would not be a worthwhile upgrade. I think the whole point of getting a cheap dual-core chip and not to spend the extra for the i3 is to make it easier to justify upgrading to i5/i7 later; going from one entry-level dual-core to another seem rather pointless, and the improvement would be so little. Think OP's best bet is to look at 2nd hand i5 as mentioned above - non-K i5 2500 has be going for around £90, and i5 2500K around £110-£120.
Added the other person you forgot to quote.
http://techreport.com/r.x/desktop-trinity/bf3-beyond-16.gif
http://techreport.com/r.x/desktop-trinity/crysis2-beyond-50.gif
Latency is horrible with the dual cores with certain engines. Those two engines alone don't seem to like dual cores,especially when decent latency is important for such games.
Move onto games like Deus Ex,The Witcher 2 and BL2 and they all use more threads well. Even a Core i5 530 would probably do better.
I hate to think how badly they will do in Warface(online) and Mechwarrior(online),and both of those use CryEngine3. A number of MMORPGs are going to use the same engine now. When UE4 is released this year,it will most likely not like dual cores,especially seeing how UE3 is ATM and that is old. Loads of big selling titles use UE3 ATM.
Maybe if you run Skyrim,yeah a Core i3 looks overpriced,but then I don't play that game.
Having said that Skyrim:Online was first demoed on an engine which could thread well. It will be interesting to see if the custom engine now used,does the same. Its not Creation,it seems which was Gamebryo on steroids. It would not surprise me if they use the new engine for the next Fallout and that would interest me.
Now,is a Core i5 for £90 to £100 a better CPU?? Yes,but if the OP has only £50 to £60 to spend for quite a while,then a Core i3 for around £50 would still be
reasonable upgrade overall for their PC. If they can save up some more,money then yeah,get a Core i5.
Anyway,I went from a new Core i3 2100 at launch to a new Core i5 and it cost me under £120 in total. Buying a Pentium dual core would have not saved me any money at the time,since the Core i3 CPUs sell for more secondhand anyway.
I not only game but use also use image editing applications,and a Pentium dual core would have been reasonably slower in that case too,and for the VM stuff I run also.
Anymore than £40 to £45 is waste of money for a non-HT dual core and the G2020 is £45 and the Celeron G550 is £33,and those are the only two which are worth getting IMHO. The Celeron G1610 is overpriced since it is virtually the same price as the G2020 and has less L3 cache.
When Haswell gets released over the next few months,prices of the Core i3 should drop even more. Core i5 prices are likely to be stable and might even go up a tad I suspect,if socket 775 was any indication with the quad core CPUs on that platform. Since they are touted as the best value for money upgrade path for socket 1155,then they will be in demand. Plus unlike graphics cards and K series CPUs, they have a very low chance of someone pushing silly voltage through them,since you can't overclock them either.
