CPU: 2 x Intel Xeon E5-2637v4, 3.5GHz (4-Core, dual threaded, HT, 15MB Cache, 135W) 14nm
RAM: 128GB (8 x 16GB DDR4-2400 ECC Registered 2R 1.2V DIMMs)
Graphics: NVIDIA Quadro P4000 GPU, 8GB GDDR5, 105W, Single-Width, PCIe 3.0 x16,
Seagate 1TB Exos 7E2 HDD (6 Gb/s, 7.2K RPM, 128MB Cache, 512n) 3.5-in SATA
just a quick build i did over at Silicon Mechanics
The dual CPU setup doesn't help Lightroom either -- it's not terribly efficient for multiple cores so I can't imagine it would do any better for dual CPUs. I'm trying to find the adobe faq on the topic I thought I've read about that.
Quadro has some merit if I wanted a 10-bit workflow since I already have a 10-bit panel.. but I did kinda want to dabble in some gaming and VR with this build as a side-benefit so I went with a GTX card.
You would figure that's an obvious and simple feature to offer, at least as an option.
This really depends on what you are editing. 13mp snaps from your ancient DSLR? Yeah, no point. 52mp snaps from your digital medium-format camera? You'll probably want more than you'd think. 4x5 or 8x10 negative scans? Open the bloodgates.
(and remember that by default Lightroom does not parallelize across multiple photos within a batch job, so multiply your measurements by 4x or whatever if you're going to be launching multiple batch jobs at once to fully occupy a high-end processor.)
128 GB is overkill, but there's a solid justification for at least 32 GB or 64 GB for power-user situations.
Overall, with your Silicon Mechanics build they'd probably be closer to a $8000 build. On top of that, a P4000 is pretty much a beefed up GTX1060, which gets smoked by a GTX1080TI if one is going for GPU performance. They're not really comparable builds.