Re: Confusion for 3D users - iMac or Mac Pro which is best?
Humm, to be blunt it would behoove you to learn more about the benefits of various technical components of a computer if it is your responsibility to purchase the equipment for your business. As you can see the decision of what computer to buy can be very difficult if you are not sure as to what specifications you need. The basic requirements for your application are quite minimal but only you know how heavily you use the software and how quickly you need the software to finish its job.
Now I will talk about a few aspects of the components to hopefully help you make a more informed decision about what system you should purchase
CPU - Well this is the brain of the computer. It controls how fast things get done and how many things can get done at once
Clock Speed - written in Ghz (older CPUs were Mhz) so like 2.1 Ghz or 3.4 Ghz. Higher number is faster and debatably "better" in that it can make more computations at once.
Cores - More logical cores means the CPU can run more tasks at once. It used to be that a CPU could do one thing, move onto the next, and so on. Now with multiple cores the CPU can run a task on each core. In high end professional equipment like the Mac Pro, 6 or more cores means the computer can be working on many projects at once.
So when you make a decision on what CPU you are to purchase, ask yourself how many major CPU tasks am I going to be running at once? For a typical consumer a simple dual-core CPU is more than enough as it is able to complete tasks like web browsing or streaming music so quickly that it is irrelevant how many cores they have. Now for a professional who might need to have their computer work on a complex rendering project, it would be nice to use the computer for other things while it is doing that. This is where having a 6-core machine (or more) comes in quite handy.
If you are setting your automated/rendering tasks and leaving the computer to finish its job you would probably find a quad-core CPU (generally regarded as high end on the consumer market) to be sufficient. If you need your computer to be capable of working on multiple projects at the same time, you are going to want a high end Xeon processor with 6 or more cores.
Note that it is a little more complicated than that as some software can be coded to make use of multiple cores to make it more efficient. This is a very broad generalization. Get in touch with your vendor and ask them about the benefits of using their software on higher end machines if you are still not sure about the number of cores you would like.
RAM - Well this is the amount of active memory the computer has available to do tasks. So for a consumer 4 or 8 GB of RAM might be sufficient for daily tasks like browsing the web or watching movies. A gamer might like 16 GB or more because they are running graphic intense 3D games and would like to play those games at a very high frame rate. Now a creative professional could use all of that RAM for the same reason - they are running big 3D applications and they want as much in active memory as possible so the computer doesn't stall while loading things. If you are looking at a professional grade machine, odds are 16 GB or more of RAM is going to be very beneficial to you.
At the high end you get server level devices that have 64 GB or 128 GB of RAM (or more) that need all that RAM because the computer is hosting many users at once who are all running tasks on the system and would like their software all stored in active memory.
Storage - So there are a few different kinds of storage out there but the two main ones are HDD and SSD. HDD or hard disk drive is an older mechanical drive of the type you probably have in your computers now. It is given a speed rating like 5400 RPM. It used to be that there were many different rated speeds on HDDs on the market but these days 5400 is really the only one you will find unless you go to a specialty vendor that still sells different speeds. The higher the number of RPMs the faster the drive and typically the better the performance. Again like CPUs it gets a bit more technical than that but it is an ok rule of thumb.
Now SSD or solid state drive also known as flash storage is a different kind of drive entirely that has no moving parts. Its performance is much faster than any HDD regardless of speed. The disadvantage of SSD is that it is many times more expensive than HDD so many people who need a large amount of storage available still use HDD to store their data.
Now of the computers you listed - what should you buy?
Well figure out how many cores you need. Multiple projects at the same time? Get a 6-core. Completing tasks one at a time and not necessarily needing the system while it is rendering? Get a quad-core.
RAM - Well more is better. You can probably get started with 8 GB (good news is these systems can all be upgraded by you down the road) but you probably want 16 GB minimum.
Storage - Really only you can know how much you need here. Do you have many different large projects taking up a lot of space? Do you move your data around a lot?
Now you should figure out what CPU you want and then go from there. Remember for iMac 5k you are getting a built in 5k display but the machine is ultimately not as upgradeable as the Mac Pro. The Mac Pro uses the Xeon processors which are meant for professional grade work while the iMac is using the Core i7 CPU which is a consumer CPU. Core i7 can very possibly do all your work for you if you are a one or two man operation but the Xeon may be significantly faster if you are doing many things at once on your computer.
I strongly advise you contact the vendor for your software or network with other users of the software in your field so that you can know what kind of system they use for their software.