re: To upgrade, or not to upgrade...... my video cards....

Just did a little research on Revit itself. When it comes to rendering, it is entirely CPU-based. You said you rarely do any rendering, but I just wanted to confirm that upgrading the video cards will not improve rendering performance unless you tend to export your models to a third-party program that specifically is optimized for GPU-accelerated rendering.

Further, most of the 3D modeling calculations are offloaded to the CPU, which will be responsible for generating the geometry you see on the screen (whether in elevation, 3d, plan view, or whatever other options available). The GPU power comes into play when you want to work with "realistic view" textures, shadows, and lighting features. Fortunately, unless you're working in high resolution, the GPU is still not a budget-breaking requirement. You would not need an overpriced Quadro card for this environment. One thing to understand about the Pro video cards vs. the consumer/gaming cards, is that one is not necessarily better than the other. Particularly, Revit appears to use DirectX graphics acceleration these days, rather than OpenGL.

The Pro graphics like Quadro and FirePro tend to offer less raw performance per dollar, but are often touted as preferable for a business environment due to the following advantages:

- Vendor support. There is a bit of a certification/validation "racket" at play here for certain programs. The autodesk suite, for example, certifies the Pro cards rather than any of the mainstream gaming cards for their software, meaning you are guaranteed driver support from NVidia/AMD and software performance support from Autodesk. This does not mean they are or will always and absolutely be the best performers in every environment. This is akin to Cox not offering help or any guarantees of service through your ASUS router because you aren't renting their Residential Gateway and instead opted for your own router.

- Rendering accuracy. Again, this only applies to GPU-accelerated rendering (so it does not apply to Revit), not the actual modeling, as the number crunching is based on the raw model data, not what is on screen. In addition, this accuracy is in regards to better OpenGL performance, which you will not see in Revit, which uses DirectX.

You would get a significant bang for buck advantage with an NVidia GeForce GTX card in Revit. A $300 consumer card would give you better performance than, say, an $800 Quadro. Though without knowing the details of what kind of models you create and what sort of graphics settings you prefer (realistic textures, shadows, anti-aliasing, etc.), I can only guess that your CPUs will become the bottleneck in these machines no matter what else you upgrade.

If the GPU-intensive visuals are important, there is still another potential problem with upgrading the cards. The T7400 appears to use a 1000w PSU, which would be sufficient for a modern graphics card, if it weren't for the fact that this is a non-modular PSU with 5 12v rails. Each rail is rated for 18 amps, and the PCIe power cables are on a single rail. Any worthwhile GPU upgrade will exceed that amperage under any reasonable load, and your PSU will simply trigger its built-in over current protection and shut down. The workaround would be to buy a double-molex or SATA power to 8-pin PCIe adapter to bring part of the load to another rail, but there's no guarantee that this will be stable in a work environment. Depending on the age and the design of the PSU, splitting power across rails can be problematic. Worse, Dell's PSU design/wiring for this workstation appears to be proprietary, so swapping it out with a modern single-rail PSU wouldn't be possible.

With your addition of RAM and SSDs, alongside the age of the socket/chipset, PSU design limitations, and the several iterations of Rivet that have followed, I'm afraid you've probably reached your limits with these particular machines. If you aren't having any serious problems with them, you could wait for a forthcoming new release in Intel's extreme/enthusiast series platform, Haswell-E with the X99 chipset and the new socket 2011-3. There is not yet a firm release date yet, other than 2H 2014, but the general features are already known.

For one, Haswell-E will have 8-core hyperthreaded CPUs (8 physical + 8 virtual), and no doubt a refresh of the expensive 12+ core Xeons. Xeons are marketed for the workstation, but you can get better performance per dollar from the i7 in Revit if you aren't planning on a dual-socket system. This will depend on your budget, because your focus should be on as much CPU performance as possible, without going too far past the point of diminishing returns. Another thing to look for is the highest single-threaded performance for everyday Revit use, as the multi-threading will have the most impact only in rendering.

X99 will also be the first platform to introduce DDR4, which operates at lower voltages and higher available frequencies. The X99 platform and its predecessor both support quad-channel memory as well. You'll likely see an advantage with quad-channel in general for processing large data sets simultaneously. One drawback is that DDR4, being new, will likely be sold at a premium and not offer any real advantage over DDR3 until later on when we see the higher-speed modules able to run at lower latencies.

When you do decide to replace your workstations, I highly recommend you go with custom builds (and I am totally available to assist with any and all steps of that process, as I've done for quite a few TDers already). For a high-end workstation build, the extra raw performance you get per dollar is substantial. Plus, custom builds can be so much more modular than a pre-built, which will contribute to longevity. You can use a high-wattage and higher quality power supply that will last through the upgrades and not have any proprietary design to overcome. You'll have a motherboard with significantly more overclocking freedom and stability, and a case that can accommodate higher performance cooling which will further contribute to that overclocking performance and greatly enhance longevity. You'll have more room to add storage drives and keep your old ones, room for expansion cards if you want to extend the use of your workstation with sound cards, a second or third or fourth video card (if you happen to start using a rendering program that is optimized for SLI), RAID controller cards, video capture devices, TV tuners, etc. There is a significant advantage in compatibility when it comes to upgrades as well; for example, you'll have far fewer issues buying compatible RAM and can choose from just about any vendor or manufacturer.

Another advantage is designing a targeted system. The Dell is marketed as an "overall" workstation, but not all programs can take full advantage of every component in a generic workstation. Doing a custom build allows you to take that same $4-5 grand and allocate it to hardware that will give you optimal performance for your situation, and if your situation changes, it's easier and more cost effective to add on and upgrade as necessary, while still getting peak performance from the get-go.

You'll also have the benefit of getting individual support for each component, including direct warranty service that's not bound by Dell's specific terms and conditions. And being able to choose each component for the build adds an invaluable level of reliability that you cannot get from an OEM like Dell, which sources its parts based on agreements with particular manufacturers that put consumer-level products under serious component-reduction processes just to squeeze a few more dollars of profit from each machine.

I know this is a wall of dense text Just let me know if you have any questions or need clarification on something.