I am a professional research (academic) who does high-end statistical and geographic analysis. I'm starting a new job and have a research fund that I can use to buy a computer from either HP or Dell. Basically, I'm looking for a machine that will be good for processing very large data files (think 50gb; millions of records) and doing sophisticated mapping analysis. I'd like to keep the total cost (including monitors) under 5k, but my main question is whether it is really worth the extra money to buy a workstation (e.g., Dell Precision) vs. a high-end business desktop (Dell Optiplex 990). I can spec the latter out - with dual 24" ultrasharps - for about 3.5k; a comparable Precision is above 5k. Here's the requested information.
(1) Servers gives you redundant parts to mask some failures and error checking. What's that worth to you? (I use a desktop not a server) If your high-end statistical and geographic analysis runs for weeks before completing and need to be accurate think error correcting (ECC) memory -- that's server stuff.
(2) Find the software you will use and see if there is an ideal configuration for it. Look for GPU based acceleration, CUDA, OpenCL.
(3) At the high end intel (>$1500) i7 is a good answer for CPU. hard to go wrong.
(4) If your analysis benefits from lots of disk data and performance look into a RAID10 array of four drives. Otherwise use RAID1. Any intel i7 MB supports either, you just need the sata ports. You are more likely to find 4 free ports on a server, and i7 MB will have two sata ports for disk drives in raid1. An add-in card for satra/raid would work also.
(5) Create and follow a backup strategy. Think NAS. You don't want to lose a month's work. Include it in the budget. That'll eat another couple hundred.