Workstation for Simulation (analysis)......

I think I would go with the Dell for no other reason then I have not heard anything good about Xi when it comes to support after the sale.  However there are other plusses for the Dell.

I am assuming the Dell you are looking at is a T5500 or T7500 series Precision Workstation.  Those are dual socket motherboards.  When combined with a Xeon 5600 series cpu you will have the option of having both cpu sockets filled on the mobo.  This would be 12 cores (or 24 with hyper-threading enabled) if you purchased 2 cpu's.  I suspect you will also be able to load up the Dell with more memory then the Xi system.

The Core i7's are great processors, they are marketed for the enthusiast/gamer.  Because of how Intel is marketing them they can only be used on a single socket system.  This is one big reason the Xi is less expensive compared to the Dell.

SSD's are very nice.  I have an OCZ Vertex in my computer and it is very peppy.  They are very high cost though per gig.  You need to decide if the speed increase offers the ROI to justify the costs. I suspect it will if you do a lot of FEA.

If buying the Dell for a corporate account you may be able to negotiate a better price.  We never pay the price on the web for Dell computers with our corporate account.

Another thing you can check on is buying only the minimal amount of memory on the Dell.  Then look at after market memory modules, they are often less expensive then buying from Dell.  Check out Crucial and Kingston and do a price comparison.  You may be able to save a good chunk of money.

My money is on the Dell for your situation with heavy FEA use.

Cheers,

Anna