Hi mate,
In your case, if you can budged for a server, it would be the best choice.
I am not sure about dell but currently I can talk for HP as independent HP Server&Storage Pre-sales Engineer;
There is a new CPU family is being used and you will be able to use Ivy Bridge 3rd Gen Intel Core Processor (Intel® Xeon® E5-2600 v2 processors). And that brings lots of new things like increased performance of up to 35% as well as makes you to have significant benefit from using PC3-14600R R-DIMM RAM kits instead of PC3-10600 or PC3-12800. I want to mention, You can use up to 768GB memory(currently only LRDIMM, cos unfortunately only it has 32GB quad rank modules. that makes 32GBx24 DIMM=768GB). Certanly, you may want to stick on PC3-14600R as I do. So in this case nowadays you can reach maximum 512GB RAM. That is 16GB x 24DIMM. (As I will say soon, those server comes with two socket. if you have only one CPU, you can use 12 DIMM activated. If you wanna install more than 12 ram kits you need to get the second CPU (And redundant power supply as well

))
by the way: PC3-14600 1866Mhz / PC3-12800 1600Mhz / PC3-10600 1333Mhz
Yes, those servers come with 2 socket. Expensive but you may want to use, CPU Like E5-2695V2 or E5-2697V2. Each of them has 12 Cores. That means you can have total: 2 CPU ,24 Cores, 48 thread of execution... It will be a killer..
I may want to mention you about RAID advantages to improve the performance, but it's getting deep technical

At the end, my recommedation is Server instead of WS. (HP DL380P Starting from $ 1,799 in US)
You may be interested in this link. I can make you server configuration advice for free
http://www8.hp.com/us/en/products/proliant-servers/product-detail.html?oid=5177957#!tab=specsCheers bro,