Motherboard and CPU

I have Nvidia Gtx 750TI and I3 3240 and i think that it's worth to upgrade from duo core to quad core or am I wrong?

I think i could buy a GPU, does SSD enchance my gameplay experience? Or maybe you could even recommend me a better processor? I'm not that guy who wants to play new guys but for example I would like to play H1z1 with solid fps.

Yes it does. But the ingame effect may be muted. It does help overall, and gets you in the game much faster and so on.

I don't think the CPU change will give you any payback. The old i5 2500 was noted to run 3 GPUs at full speed so your CPU is better than that so there's no gains there.

Nod to GPU and SSD of course. Have you used a machine with SSD?

No I haven't, no experience in this kind of technology.

Here the 480GB SSD can be snagged for about 100USD on sale.

While I can see folk think it's the CPU and may want to bump that, the GPU and SSD are where the gains for the buck are.

How do I know what SSD is compatible with my motherboard?Maybe you have a SSD recommendation? And should I focus on upgrading my GPU and leave my CPU? When should I even upgrade my CPU?
PS. Sorry for soo many questions I'm just very insterested in upgrading my computer properly.

Unless your board is over a decade old with IDE ports I have yet to encounter an issue. In fact I never check today.

OK, I see you're not convinced on the CPU. How about this?
"Our tests demonstrate fairly little difference between a $225 LGA 1155 Core i5-2500K and a $1000 LGA 2011 Core i7-3960X, even when three-way graphics card configurations are involved. It turns out that memory bandwidth and PCIe throughput don't hold back the performance of existing Sandy Bridge-based machines. "
http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106-4.html

So let's compare that CPU.
http://cpuboss.com/cpus/Intel-Core-i5-2500-vs-Intel-Core-i3-3240 does not convince me to change the CPU.

All the bang for the buck gains are in other areas.

What SSD? I've been using Crucial, Silicon Power, Sandisk, Transcend and Samsung. While you could get into analysis paralysis, I know to pull the trigger since SSD beats HDD every time.

Last questions before I'm going to upgrade my pc. Is my motherboard pci 3.0 for graphics card? Is it very hard to change from HDD to SSD?

There's another area kicked around to no end. That is, if you took a GPU like your 750 in PCIe 2 and 3, the benchmarks would be so close that it's likely something else changing the results.

I've changed dozens of HDDs to SSD and for me the best tool is something like the Apricom USB 3.0 hard drive clone kit. This way it's 30 bucks for no pain cloning. But your choice if that's worth it.

I'm going with less work than a CPU or GPU change.

IF i would change my GPU for GTX 960 would my CPU run it with out bottlenecking?

I tried above to show the i5 2500 driving 3 GPUs and comparing that i5 head to head with your i3. It's so close that I can't see any bottleneck issue with a single GPU.

I know it's hard to wrap our heads around this but Toms did cover this.

Here's your gains from 750 to 960. Enormous, huge tracts of land.

http://gpuboss.com/gpus/GeForce-GTX-960-vs-GeForce-GTX-750-Ti

We know the overall score is well, to be tossed as BF3's framerate went from 50 to 80. That's a huge gain and it's all of just one gain.

Well I have 64 bot OS with 8GB of ram, planning on getting upgrade after I upgrade my GPU

Is this ram set up in dual channel?

If so not much bang going above that amount.

Yes it's 2x4GB

Speccy reports are what I use to deep dive into an unknown PC. It can check if the memory is in dual channel mode. Just because you have 2 sticks, it's still possible to be in single channel mode.

OK, how much gain? Enough to check but all the gains past this are not in the CPU or more RAM.

Speccy is at https://www.piriform.com/docs/speccy/using-speccy/publishing-a-speccy-profile-to-the-web