In context: A base clock of 1.4GHz may seem low but keep in mind, we're dealing with 64 cores here. The more cores you stuff into a package, the higher its overall thermal load will be. Even on a more efficient 7nm process, heat is going to be a concern with that many cores in play.
Leaked benchmark results from AMD's 64-core, 128-thread Epyc Rome processor have surfaced. The results, spotted by Tom's Hardware and taken from SiSoftware's Official Live Ranker database, are from a chip identified as an AMD ZX1406E2VJUG5_22/14_N.
According to the publication, this is a qualification sample that is very close to what will eventually ship from AMD.
In the two most recent tests - processor multi-media and processor cryptography - dated March 27, 2019, the test system is listed as a Dell PowerEdge R7517. The chip itself is identified as having 64 cores, 128 threads, a base clock of 1.4GHz, 64 x 512KB of L2 cache and 16 x 16MB of L3 cache.
It's worth reiterating that we don't know which specific model chip this is. It's entirely plausible that this may not be a flagship part and thus, might have a lower TDP.
With any luck, we'll hear more from AMD at Computex which kicks off on May 28 and runs through June 1 in Taipei, Taiwan.