Okay, I wanted to start a dialogue about computer technology for Revit.  I have attached a few Autodesk related items that you can take a look at too.

Here's my take in my experience and reading other forums about others' experience using Revit.

1)  RAM:  The biggest things you can do is get A LOT of fast RAM.  If you can afford it, get a new computer with at least 8 GB of dual channel RAM.  I would suggest RAM running a frequency of 1066 mhz.  Usually this is called out as DDR2 1066 or PC2-8500 RAM.  If you can afford the upgrade and have a motherboard that can support it, I would suggest DDR3 1333 mhz in triple channel (identical sticks in sets of 3).  Most new motherboards supporting this technology will have 6 DIMM slots instead of 4.  Also, related to this, you should see some performance gain when using the new Intel Core Series of processors, due to the new integrated memory controller.

2)  CPU:  The CPU is the next biggest thing.  Almost all mainstream processors out there are at least dual core, and many new computers offer quad core.  Here's my take:

a.  Get the fastest processor you can afford.  What I mean is, I would probably get a 3.2 ghz dual core over a 2.4 ghz quad core, unless you are doing a lot of multi-tasking.  Currenlty, Revit doesn't support multiple cores with the exception of a few areas like printing and wall cleanups, and of course Rendering (currently limited to 4 cores).  There is every indication that Autodesk is working on multi-core support, but given the complexity of the database structure with tons of co-dependencies, it may be a few more releases before Revit is optimized across most of the platform for multi-core support.

b.  Get the CPU with the larger amount of L2 cache, assuming all other things equal.  This is a suggestion by Autodesk as well, as the program takes great advantage of the L2 cache.  I have seen this as a peformance difference as well.

c.  Core i7 turbo mode.  This is really huge, as I tested a laptop that had a core i7 1.8 ghz processor in it, and with Turbo mode working, Revit ran at almost 3 ghz for the majority of it's single threaded operations.  This can be a big cost saver if you anticipate being able to utilize this feature, and your budget is tight.  As I mentioned previously, if you can affort a "out of the box" Frequency of 3 ghz or more, go with that.  You'll only see greater results with a processor like that, when turbo mode puts you up to 3.4 ghz or more!

3)  Hard drive/Graphics Card:  this one is a toss up for me.  If you are doing a lot of work in 3D views, or Rendering, the Graphics Card would probably be the best bang for the buck.  If you are using a more traditional workflow like me, where you work in Plan section and elevation, I think the Graphics card doesn't have as much of an impact yet, and I prefer to see my entire computer perform better with the used of a 10K or 15K SATA 2 Hard Drive.  There has been much talk also about using Solid State drives, and assuming they benchmark in Revit similiar to other applications, you should see a large performance increase while loading and saving files, not to mention just overall better response and performance in your entire Computer.

a.  In relation to this, I would suggest having at least 2 drives, one for your operating system, and one for your files.  This enhances data security should your OS get a virus, as it most likely will only affect the OS on that drive, and you'll also see added performance as you know have two drives with which to read and write data (one for the OS and pagefile, and one for your Revit File and other files).

b.  As far as the Graphics Card goes, I would suggest just going with a Desktop level card.  Since Revit has gone Direct 3D, I don't see any reason to pay outlandish cost for a Workstation card like a Quadro when you can get a GeForce card with double the performance at half the price.  There may come a day when the Quadro cards are optimized for Revit, but currently I don't believe you will see enough of a difference to merit the difference in Cost.  If you are working 3Ds Max or 3D AutoCAD, that's a whole different story.

For the GeForce Card, try getting a card with (preferable) 1 GB of on board RAM, as this will greatly reduce the load on your CPU while regenerating 3D views.  Obviously the faster the GPU, the better.  I would look for core clock speeds greater than 600 mhz if you can afford it.

I would love to answer any questions or hear other peoples stories/thoughts related to this post.