Do not be angry, but it seems that these guys do not know what they make.
If you have a chip with 192 cores asics performing a hash per cycle.
520,000,000 cycles are 520 Mhz 99840000000 hashes 99.84Ghs
620,000,000 cycles are 600 Mhz 115200000000 hashes 115.2Ghs
But this is not important, the important thing is to know ETA chips.
You're right. It's not important.
But other then that
of course they don't know what the final specs will be. They won't know that until the chips are done. It depends on the yield as far as the hasher engines. It depends on thermal output. It depends on a lot of things. Avalon chips are actually underclocked and
undervolted, presumably to help with cooling and power, yet
they perform 36-40% better then what they were advertized as. . That's because Bitsyncom gave themselves a large margin between what they advertized and what they were designing for (their chips work up to 450Mhz at the right voltage)
Actually you do know the performance of the chip before it's made.
The ASIC vendor will give you timing models and you run static timing analysis on your design and it will tell you the critical path and how fast the device will operate.
However, in most cases the produced device will be faster than the spec. Hence it's possible to overclock the device. But you have no guarantee that the next batch of devices will be as fast, it might be slower, or it might be even faster.
As for thermal they should have a pretty good idea. You try to run a worst case simulation where you generate a VCD file which will show how all the nets in the chip is toggling. Then you run this through some power estimation tool (given a specific package) given by the vendor. This is not 100% accurate and depends on how representative the VCD file is for your worst case. But it gives you a pretty good estimate. Then there are tools to simulate the thermal characteristics of your mechanical system.