I'm more of a desktop guy and I got the Pro's (WRX80) confused with the non Pro's (sTRX40) which do have 256GB max capacity. The Pro's weren't really my jam until this article. I'm getting up to speed though. Tom's and Anandtech are big helps.
Still not quite right ... your specs are from way back to first and second gen ... 3rd gen desktop is 1 TB and the 3rd gen "pro" versions are 2TB, (but I guess 4TB "in theory" like the other guy said). The "pro" versions just straddle the space between EPYC and regular desktop TR
AMD Ryzen Threadripper 3990X processor specs, with the number of cores, threads, cache, max PCIe lanes, the power consumption, the maximum RAM memory capacity, as well as the performances.