Running that box with just one CPU in was giving ~50 mins plots (under Win ). Once the second CPU was added, I was killing it around 1+ hours, as there was no point to continue that agony. My understanding is that Win 11 Pro just cannot bite NUMA settings (multiple CPU). Once I switched to Ubuntu, all was over.
I settled down on ImDisk (on that i9 box). I was trying Romex, some other RAM disk utils, but ImDisk was free, and if not faster, it was equal to other utils. Although, when I had just 64 GB RAM on that i9 box, I used Romex’ Primo Cache (giving it ~55 GB RAM, and pointing it at t2). With that setup, it was taking ~50% hits off of the t2 folder (a second NVMe).
I have tried on that box (Ubuntu) to run a single instance of MM all in RAM, a single instance with t1 as NVMe / t2 as RAM, but all those various settings were slower than running 2 MM instances in parallel, each having it’s own NVMe, and 128 GB RAM sitting on each CPU.
My DDR3 is running as 1886 MHz (max on that motherboard).
What you need to also consider is the power draw of that box. During plotting, my box draws ~450W. The TDP for 2695 is 115W, where 2660 95W. However, 2695 has a couple of extra cores, more cache (30MB vs 25MB), and runs at slightly higher clock rates (2.4 vs 2.2). So, I would really get 2695 / 2697 (higher clock rates, higher TDP).
Also, you should use NUMA control, as that speed things up a bit more (just search this forum for NUMA, as there are a couple of great threads about it being used with parallel MM - of course for Linux). Also, some people reported that MM was faster with CentOS or Debian rather than Ubuntu on those dual CPU boxes (maybe on single CPU as well, don’t recall it).
By the way, I got Dell Precision t7610 workstation for ~$250. Each CPU was ~$100. RAM is the most expensive part. I got 32 GB 1886 LRDIMM ECC sticks, but some people were getting 1600 (a bit less expensive), and overclocking those to 1886 without any problems. Also, I had to switch to water cooling, as that motherboard really sucks (hot air exhaust from CPU1 is 1" in front of CPU2 intake, so the stock fans were making jet noise, plus the box was temp throttling).
If you have plenty of plots to do, maybe getting that box with 512 RAM and using BB would be a better route for you (effective plotting times closer to 15 mins, or so).
I think that those dual / quad e5-2600 v2 boxes are potentially the most cost efficient for medium size farms.
When you mentioned that you were running 4 plotters in parallel, were those MM or rather Chia plotters?