When would you stop upgrading and replace?

You forgot to mention the specs on your MacPro.
I am not sure what MacPro(1,1) specs are.

 

It is still a pretty good machine, so that is a tough call. Are those the dual core or quad core xeons? I can't remember. But I would definitely enjoy a quad tower over my C2D iMac.

 

I think that you are also able to upgrade the processors in that mac pro and put dual quad cores in should you so desire. I wouldn't go to the imac due to losing the drive bays and expandability. I still run a G4 that has SATA and USB2 that would not be possible without the expansion. I am looking at getting a 2008 mac pro at the moment. In your position I would choose option 3

 

Dual Core per CPU, so 4 cores total.

OP, what do you use it for?
For general computing, it's a good system. In fact, they're still good for photography work (PhotoShop can only utilize 2 cores right now). But if it's being used for video/graphics editing (i.e 3D work), not so much anymore.

 

I have the same machine and it still works quite well. I do a lot of HD video and I can begin choking from time to time but overall it gets the job done. I'd like to think I can get another year out of it before I NEED to upgrade to a better system.

 

To the OP,

Those options look like sidegrades to me. I don't think any of the C2D machines you mentioned would outpace your current rig. What's the advantage of replacing it?

 

If you really want to buy an iMac, get at least one of the i5 or i7 processors.

 

I'd get my son to quit Warcraft.

Would be cheaper overall.

But if it really came down to it, I'd do the upgrade because going from an iMac to a Mac Pro later on will be quite difficult (financially).

 

I'm just wondering, why did you get a MP in the first place? Are you not using it because you have something better?

Going to an iMac is just plain STUPID. It's like trading in a 3 year old Lexus to for a new Corolla!

As for upgrading video, I don't see the need for it if all you (err, your son) want to do is play WoW and some such.

Your MP has at least a couple of good years left in the tank for how you're using it.

 

I'd have to agree with akadmon. iMacs are consumer grade machines and just don't have the level of build quality that your Mac Pro has. Your 3+ year old Mac Pro has a very good chance of outlasting a brand new iMac that is purchased today. Furthermore, the fact that you have been able to add upgrades to your machine over time should reinforce your choice to stick with the Mac Pro.

 

I think 3-4 years for most heavy users. I am a light user so I usually get 5+ years from desktops and laptops. My Power Mac was 7 before it was retired as my main machine. My iBook was 5 years old before it became a backup machine, meaning that it really never got used much after that.

But 2 years or less, with replacing machines, is common with those with GAS (gear acquisition syndrome). It's a common trend for my Mac clients, when I was a techie, to see them get the latest and greatest in January, lust but sometimes refrain a year later, but definitely get the latest and greatest in the second year. Technology still moves at light speed, so by the time any Mac is 2 years old, the cheaper, more well equipped Mac at the store is hard to pass up for the techie inclined users.

I go a long time because to me, my Mac is a tool, a fondly loved one, but still a tool.

 

Upgrades on that particular system will be limited though (for OS X), in the near future. Graphics cards are already becoming a problem (nVidia's more recent offering's won't work). So far, ATI cards are still working, but it may not last that much longer (hopefully will, but no way to be sure). Assuming the graphics card requirements won't exceed what the 4870 can do (hopefully the 58xx will too, if/when released for Mac), it can get you a couple of years or so.

Then there's OS X. Once it goes exclusively to K64, those versions won't work on the EFI32 systems. So as long as the newest version isn't needed, it will still have life in it.

On the Windows side, its possible to use whatever PCIe hardware you want, and it can run the 64bit versions (though a Retail disk is a bit tougher to install, due to the different versions on it = mod before it will load).

It all comes down to usage.

 

I don't like the car analogy you put forth. If you said going from the top of the line Mercedes at three years old to a new Corolla, that would make sense.

By the looks of some of the new Corollas (I have been car shopping) I would rather have one of those nicely appointed than most three year old Lexus models. But that's just me.

That being said, I like Mercedes, Lexus, and Toyota Corollas.

 

Just cram more RAM into it. You can go up to 32GB of RAM into it (Apple says only 16GB, but they lie) Add a new GPU, an SSD boot drive (or RAID 0) and you'll be screaming for at least another year.
That's why I got my Mac Pro; it's cheaper and easier to upgrade over time than get a whole new system every time you need more speed IMO.