A P490 is a great base platform but they are getting old these days... not terrible but there are better things out there simply that are quieter, smaller, use less power and equally as fast - but then again that depends on the user and the application. I use P490's and P690's for BSD based data servers/databases all the time and I'll keep doing so for years since they are currently so overkill. As a desktop it depends on the user - the biggest benefit/drawback to the P490/P690 is that they are packed with PCI-X slots and have few PCI-e slots. The T5400 is a better balanced solution but still not quite as cheap as the P490/P690. I think there is a use for everything... if it is appropriate I will keep the P490/P690 around for years & years - or dump it tomorrow. It all depends. Also, DDR2 has gotten expensive and the P490/P690 chassis stopped production some time ago so it is still in a sweet spot where it is cheap - but if it gets "rare" and therefore expensive it will be 100% moving on to the T5400/T7400
Now I assume you are getting these things as used ones. And this brings up another issue. If you could get it as brand new and cheap, that is one thing, but if the machine already has 5-8000 hours on it, that could and will effect its reliability. The Precision line is 5 years old already I think... For the OP, I have found this website, selling Dell Precisions, with 1 year warranty: http://www.stikc.com/Catalog/Dell-Precision-490 $325 or the P380 for $250, P390 for $300... The T5400 is almost the same, $369...
I buy them by the pallet (a lot of 5-15 machines) from Dell or other certified resellers. They are all new or factory refurb parts, they are all burned in by me prior to delivery and they are a great deal for the money. I only charge $150 over parts/cost to assemble, configure and burn in no matter what the specs.
As for new vs old, if a pc is very old then it is probably too old. I have an 13 yrs old thinkpad that still runs very well, all the hardware parts are working even though it has taken a lot of abuses from my kids. But the problem is that it has no wireless moderm, no earthnet jacket, no UBS port, and only 32 MB RAM.
"Very old" has the problem of obsolescence. Most of what's being debated here is "a few years old but of high quality" vs. "new, cheap quality". How does one decide? I say, "go for a quality motherboard". The other components are mostly "off the shelf/same" for all makers.
When buying a used machine how do you know how many 10's of thousands of hours those components have seen, and that it won't fail tomorrow? Workstations are more often than not staay on 24/7/365. Better buy two and setup both in advance because if one goes down.. :eek:
"Staying on 24/7/365" doesn't wear on components as much as turning them on/off a lot. Besides, we're not talking about trying to buy stuff which is 10-15 years old.
"Staying on 24/7/365"* doesn't wear on components as much as turning them on/off a lot. Besides, we're not talking about trying to buy stuff which is 10-15 years old. * Did you know? ...There is a light bulb in a firehouse which has been burning CONTINUOUSLY FOR MORE THAN 100 YEARS!!