ECC vs Non ECC Ram? Processor vs Ram?

So I've been forced to deal with an issue.
We have a very large project we are starting in Revit (~1.2million sqft), many arch and mep models, many consultants and me for structural.
I've been told I should be able to keep everything in one model but I may need to split it down the road (which is preferred at this point).
So our IT guys got us some new Z210 boxes with the i-7 chips. So the first thing I found out is that I think I'm limited in the amount of Ram I can put in it.
Second thing I was told is that the i7 doesn't support ECC ram.
So my current box is a Z400 with xeon 2.8ghz multi-threaded something or other. It has 6 slots for ram and I currently run 18GB of ECC. But I could add more. I don't think I'd need more that 32gb for this project, but you never know.

So 2 questions for the really smart people out there.
1.) Is ECC Ram needed (is there a real benefit) and is it worth the price?
2.) What's better the ability to have ECC ram and have more of it or be limited on Ram, not have ECC ram but a faster processor?
I asked for the faster Xeon, but IT doesn't want to shell out the cash for it.
Any thoughts or opinions
Thanks in advance.

These days, ECC RAM si pretty much a waste of money for a workstation (database server fielding thousands of sql call is a different matter). I don't know how well Revit does multithreading, but if it is on the same field as Acad & verticals, speed is better than cores. Can you disable hyperthreading in the BIOS of thos machines?

By limited RAM, are you talking <8Gb? That seems to be the common cut-off point. 8 is probably not going to get overloaded, so if it's a choice of 8Gb and faster processor, vs slower processor & 12Gb, you'll probably see more performance with the faster processor. If you're thinking that 32Gb is where you want to be, I don't think it will matter. 16Gb would be nice and neat.

An SSD would be nice also...

XEON & CAD does _not_ make much cents IMHO.

Well the choice is to stick with what I have 2.8Xeon with 18GB of ECC ram or go with the new 3.4 i72600 and 16GB of non-ecc ram. Both would have sim Vid Cards and SSD.
I've been more concerned with an error corrupting my Revit file than anything. I now feel save with the 16gb of ram, just concerned about the non ECC thing now that I've found out what the real reason for having it is.

Quote:

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ECC == error correcting code. It's 4 to 10 times more expensive then non-ECC memory and the two are not compatibly. ECC is always used in server class machines to improve reliability since the radiation he was referring to does make it all the way to the ground and if a neutrons particle hits the bit memory transistor it might cause it to flip the value. Not likely enough for a desktop system to worry about but servers (real servers anyway so windows excluded) are suppose to run for years without a planned outage.

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Or at least that's what a computer engineer told me.
So it seems like there shouldn't be any real issue and everyone seems to think the same thing. Don't worry about it. Our other reason for looking for ECC ram was for out engineers that are running structural analysis programs where any error that the program doesn't pick up could have a major impact later on.

based on that, the i7 should be about 25% faster than the Xeon -- possibly more since ECC tends to be slower than non-ECC (since it has to chek the results on every operation and look for potential errors). Especially if the Bios lets you turn off hyperthreading... not all do.

Wouldn't you still want to be able to use hyperthreading for rendering?

yeah, that's a good point. especially if it's a big part of your day. It isn't for me, but YMMV

We ran some tests prior to buying Dell's M6600 i-7 workstations. We found in our 3D operations, 12-13 Gb was about all the (non-ECC) RAM we used. We also found the speed increase for SSD was worth the cost. This was before the Thailand flood.
Now, we're putting SSD in our SATA 2 machines, because it is less than a $1/Gb, and we max out the performance for the hard drives. In some cases we can almost double the speed of our three and four year old buisiness laptops. In our CAD workstations, we saw a much smaller increase in performance, almost negating the advantage for SSD, but with the M6500's (which we ordered with Nvidia 3700M video cards) we have had so much issue with heat that the reduction of a heat producing drive makes it worth pursuing. So far, I haven't gathered any data on real world performance on these.
As for reliablility of data, We use to mirror all our mechanical hard drives, but we haven't been doing that for the SSD's. Haven't had an issue for nearly a year now..