Sir I have intel i3 2120 processor. What graphics card and its compatible motherboard should I choose without bottlenecking &

Solution
For the motherboard, I would say a GA-B75M-D3H:

http://www.amazon.com/Gigabyte-Intel-Micro-Motherboards-GA-B75M-D3H/dp/B007R9CRGW/ref=sr_1_1?ie=UTF8&qid=1433872914&sr=8-1&keywords=LGA+1155+motherboard

And for the graphics cards I have two options for you. Please note that bottle necking is a more opinion-based guess and cannot be a perfect science until it is tested. However, in my opinion, your cpu shouldn't bottleneck these two:

R9 280:

http://www.amazon.com/gp/product/B00IZXOW80/ref=s9_simh_gw_p147_d0_i2?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-1&pf_rd_r=101ZEBJNS91QWNVSZPKP&pf_rd_t=36701&pf_rd_p=2079475242&pf_rd_i=desktop

GTX 960...
Sorry for the confusion! On intel.com your i3 2120 says the max GPU freqency is 1.1ghz, except they were talking about the integrated graphics on the CPU. For a dedicated GPU (which is what you are getting) there shouldn't be any limit. Also, if you're concerned about frying your pc from heat or anything I'd say get the GTX 960. Nvidia is known to run far cooler. I also doubt either will fry your pc.
As for the GTX 750ti, it's a very awesome card and If this is your first time installing a GPU definitely get the GTX 750ti. It will perform far worse than the GTX 960, except many of them is literally as simple as plugging it into the PCI-E slot and installing drivers-- no extra PSU cables to plug into it. I would recommend getting this one as, since I don't know your case, this small form factor and no required extra power, will almost guarantee it will work:
http://www.amazon.com/EVGA-GeForce-750Ti-GDDR5-Graphics/dp/B00IDG3IDO/ref=sr_1_4?s=pc&ie=UTF8&qid=1439923142&sr=1-4&keywords=GTX+750ti

P.S the GTX 960 has GDDR5, that G meaning Graphics. That means it is completely separate from the DDR3 your CPU needs and there will be absolutely no conflicts.
 
I am not able to find the case "Zebronic Zeb-28R" online. Looking at the other Zebtronic products available they all seem to be pretty big. Unless you can find a URL for me with the case I would say go with the GTX 750ti I linked to you. All you have to worry about with that thing is if your case supports a dual slot GPU. To check you can just open up your case, and decide how the GPU will fit into there. Length shouldn't be an issue with the GTX 750 ti, but you mine as well check that too. However, the GTX 960 is a whole different story. This GPU is quite big and you will have to check length to make sure it will fit.

You probably won't have to do any of this stuff though, as it's rare a case won't fit something as small as a GTX 750ti in a small form factor. If you can take a tape measure and measure the dimensions of the case, and you can tell them to me, that will help me narrow down just how supporting it is of big hardware (mid atx, full atx, micro atx, etc.)

P.S I see that Zebtronics only has made 1 ITX case, which should be the only one with the chance of a GPU not fitting.
 
2e5a28d0


 


Alright that seems to be big enough. It's actually the same height as my pc ^_^ considering the depth you may have to remove some HDD cages for the GTX 960 but with the GTX 750ti there shouldn't be an issue. If you wanna be extra safe you can count the expansion slots on the back and tell me how many there is?
 


On the back of your pc you have rows of slots underneath your things such as USB, Internet Cables, etc. They are like metal brackets and are very wide and not very tall.
P.S I said the wrong thing 😛 they are technically called pci bracket's.
 


on some games yes, but the gtx 960 would be a good choice if you also upgrade the cpu down the line.

Very nice 1080p performance.


most gtx 960's require a 6-pin pcie cable from the power supply.


Make sure your power supply has such a cable available.