The Xeon E3-1220 v3 is a powerful processor, whereby it is similar in performance between i5's and i7's but at a fraction of the cost; Xeon's are cheaper with the same performance as i7's.
However Xeon processors do not have integrated graphics. Your system will not boot if you don't have a dedicated/discrete graphics card installed.
With the Xeon processor, you must have a discrete graphics card, such as NVIDIA or AMD/ATI. You must install this in your motherboard's PCI-Express x16 slot. There onwards you will be able to boot with the Xeon. If you don't have a graphics card, then you should purchase one to use with your Xeon or purchase an i5 instead.
Any other modern Intel processor, such as i3, i5 and i7's have integrated graphics; therefore you won't need a dedicated GPU. Regardless if you're working with graphics, and depending on your requirements, a GPU could be ideal for your use.
All the best.