CFD Online Discussion Forums - Harware for Numberic Stimulation ( Stock Market )

Dear all. I'm new in this forum. English is not my mother language so sorry about my bad English.

My work is building a analyse system for stock market. The system take care for over 950 symbols so the data is huge.

The system run custom scripts ( I code the scripts ) and doing calculating numbers only ( backtest, explore, optimize ), no graphic here.

I have test on 2 PCs

A- PC ( My Current PC )
* Main Giga B85M D3H, CPU i5 4440, RAM 8gb ( 2 x 4Gb ), VGA onboard
- Run 01 scripts take 12 mins
- Run 02 scripts at the same time takes 30 mins ( noted that running 2 scripts at the same time takes longer than 1 by 1 )
- The CPU Usage : 100% all the time, ram use 40%-45%

B- PC ( My friend PC )
* Main MSI X79, CPU i7 3930k ( default ), Ram 32 Gb ( 4 x 8Gb ), VGA 2Gb.
- Run 01 scripts take 5 mins.
- Run 02 scripts take 12-13 mins
- The CPU Usage : 100% all the time with 6 cores, ram use 10%

So I noted that my stock system just use the CPU, no usage for RAM. And may be not support muti-tasking.

My question is :
1/ Now
I want to upgrade my Current PC CPU ( i5 4440 - LGA 1150 ). 2 options :
- i7 4790 ( not the K - I do not OC ) : My i5 4440 + 150$ at a shop in my place. I just swap the CPU.

- Xeon E3-1231V3 : My i5 4440 + 50$ at a shop in my place. I have to buy 1 VGA card ( cheap one is ok )

Which is the better choice for me now ?

2/ Next 6 months
I want to change my PC.
- I still stick with one CPU like i7
- Change to dual Xeon ( work station )

Your advice is helpful to me.
Thanks & regards.
Duy.