- Video/Graphics Card (GPU)
- Hard Drive
The thing I noticed with my recent benchmarks testing Revit is that it did not benefit as much from an expensive GPU as I previously thought. Also, I found that steps taken that should benefit from a SSD did not produce as much benefit as I'd hoped. When it comes to OS, you better be on a 64bit platform or most of the rest won't help you.
If you are on a tight budget like I am and trying to get the most benefit for your money, I would go with the fastest CPU you can get as that seems to drive the most benefit for productivity. Next, add as much RAM as you can get, starting with 16GB minimum as Autodesk recommends.
As for a GPU, Revit did great on my benchmark tests with a mid-range card, the Quadro 600. The jury is still out on what happens with it in other applications like 3ds Max, Rhino or Sketchup. Initial experiences from our in house 3ds Max expert Chris Grant said he felt that viewport performance was very snappy, more so than his desktop running a Quadro 4000 with dual Xeon CPU's. We need more testing in other applications, but I predict the Quadro 600 will suffice for them as well. My thought is that because on our BOXX 4050 & the CPU was running overclocked, the CPU was able to hand the data off to the GPU faster for it to process things.
When it comes to hard drives, there are a few things to consider. If you are running a regular physical hard drive (HDD), RPM of the disk speed as well as transfer rates from disk to CPU/RAM affect how fast data can be read/written. You can get some pretty high RPM drives these days for HDD. I noticed on the spec sheets from BOXX that their system with a HDD running @ 7200RPM had the same transfer rate as their SSD. Getting to the data is one thing, sending it around the computer is the other part. I need to run more testing on a similarly configured BOXX with a Solid State Drive (SSD) to confirm my suspicion, but I would have to guess that running with a HDD vs SSD does not offer the performance boost when using Revit that one would hope for.
When does Revit access the hard drive? Per the Revit Model Performance Technical Note, it is only during model load, model save and any hard disk swapping managed by the Windows OS. What is hard disk swapping? According to this page on Wikipedia, it is part of virtual memory (VM) implementation in the operating system that allows disk storage for data that does not fit into physical RAM. So to me, I interpret that to mean Revit only uses VM if it runs out of RAM. If you have enough RAM, you shouldn't need VM with Revit. This in turn means Revit only really accesses the hard drive when you first open a model and when you save / sync with central. Overall, this is a far less occurring activity during the day and for only short bursts compared with model creation/editing and viewport regeneration. Also, with many large models, they are central files and a good amount of that save time is sending data to/from the server over your network. So I guess that's a long winded way of saying I don't see the benefit from the added cost of a primary SSD. I'm not saying it won't speed things up here and there, I'm just looking at the overall picture of trying to get the most value for my money.
In summary, I can't stress enough that you need to spend as much of your budget as you can on the fastest CPU you can get your hands on. It will just make life so much more productive and pay for itself much faster than other bits you might splurge on. If I had a rich uncle give me a bag full money to go buy whatever desktop I wanted, it would have the fastest CPU (multi-socket/multi-core), best dual GPU setup with a couple SSD's and as much RAM as I could stuff into it. Until then, I'll squeak by with a fast CPU and get by with lesser components elsewhere.