Will this be a huge step up for my gaming system?

[CubeIce]

So my current system is as follows:

Motherboard: Asus P5G41T-M LX3
CPU: Core2Duo E6600 @2.77GHz (overclocked 15%)
RAM: iForgot 4GB DDR3-1066 (seriously I forgot the brand)
Video card: MSI 9600GT OC (factory overclocked, beast card)
HDD: 2x 160GB SATA2 (SeaGate and Samsung)
PSU: 350W Ordi (custom-made for that company?)

This is the new system I am planning to build (note that this is on a budget ~500€):

Case: BitFenix Prodigi mini-ITX Black - 68.70€

http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Korpused-ITX-korpused/32755
http://www.bitfenix.com/global/en/products/chassis/prodigy/

Motherboard: GIGABYTE GA-B75N - 72.48€

http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Emaplaadid-ITX-emaplaadid/GIGA-BYTE-MB-B75-S1155-MITX-GA-B75N-GIGA-BYTE-21364
http://www.gigabyte.com/products/product-page.aspx?pid=4405

CPU: Intel Core i3-3240 3.4GHz - 108.01€

http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Protsessorid-CPU-LGA-1155-protsessorid/Intel-Core-i3-3240-Dual-Core-340GHz-3MB-LGA1155-22nm-55W-VGA-BOX-9284
http://ark.intel.com/products/65690/Intel-Core-i3-3240-Processor-3M-Cache-3_40-GHz

Video card: SAPPHIRE HD7750 2GB - 76.73€

http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Graafikakaardid-VGA/SAPPHIRE-VGA-PCIE16-HD7750-2GB-GDDR3-11202-13-20G-SMALL-SAPPHIRE-22070
http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1159&pid=1682&psn=&lid=1

At first I will use these with the PSU and RAM from my old PC. I could also sell my old components.
Will get these components later (next month or so):


Fan (front): BitFenix Spectre White 200mm - 10.75€

HDD: WD Blue 1TB SATA3 - 58.94€

http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Kovakettad-HDD/WD-HDD-SATA-1TB-7200RPM-6GB-S-64MB-WD10EZEX-WDC-20910
http://www.wdc.com/global/products/specs/?driveID=1092&language=1

CPU cooler: Cooler Master Seidon 120M - 52.48€

http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Jahutid-Protsessori-jahutid/35203
http://www.coolermaster.com/product/Detail/cooling/cpu-liquid-cooler/seidon-120m.html

PSU: Corsair VS 450W - 33.56€

http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Toiteplokid-PSU/Corsair-power-supply-VS-450W-120mm-fan-EU-version-37857
www.corsair.com/en/power-supply-units/vs-series-power-supply-units/vs-seriestm-vs450-450-watt-power-supply.html

Will this be a better system than my current? Would I be able to play games like GTA4, Saints Row 3, Far Cry 3 on medium/high settings (depends on game ofc) with no lag? Currently I can't run any of these games normally because of my bad CPU.
Does an LGA775 CPU cooler (stock Intel cooler) fit onto LGA1155? If not, I would need to buy a CPU cooler temporarily as well.
The reason I am creating such a small / quiet machine is because I don't want a monster PC for gaming. I'm not that seriously into gaming. I don't play on full HD or even higher resolution, and I don't need to max out settings in every game.

Thanks for your answers!

 

[tiny voices]

It will run nothing at high or close to it. The 7750 is a very low end card and you will be playing at low settings at 1080p.

You need a b75 motherboard. that board will not work as it needs a bios update to be able to accept an ivy bridge CPU.

That PSU isn't the best. I would replace it asap. (Corsair, Seasonic, antec, XFX)

 

[CubeIce]

It will run nothing at high or close to it. The 7750 is a very low end card and you will be playing at low settings at 1080p.

You need a b75 motherboard. that board will not work as it needs a bios update to be able to accept an ivy bridge CPU.

That PSU isn't the best. I would replace it asap. (Corsair, Seasonic, antec, XFX)

For the PSU: http://www.corsair.com/en/power-supply-units/vs-series-power-supply-units/vs-seriestm-vs450-450-watt-power-supply.html

And this as motheboard: http://uk.gigabyte.com/products/product-page.aspx?pid=4405#

Is that better?

So you're saying I shouldn't upgrade my video card? My resolution is 1024x768 and I won't be upgrading my monitor any time soon.

 

[tiny voices]

That video card will be fine for medium settings at your resolution.

That PSU and motherboard are great.

 

[CubeIce]

That video card will be fine for medium settings at your resolution.

That PSU and motherboard are great.

Since you are a CPU expert, you forgot to answer one question...
Can I use my current LGA775 Intel stock CPU cooler on LGA1155?

 

[tiny voices]

It isn't designed to work but it likely will. The new i3 will come with a heatsink which will work perfectly fine.