Ic2 Replicator Question

It's very much dependent on what you're trying to make. The amount of UU consumed is normally 1 mb/t, but this can be sped up via overclockers. The replicator itself has a limit on 1 item per tick however (unlike other machines that are limited to a stack/tick), so providing you can power it, that's the fastest it can go. But of course the more UU something needs the more overclockers it takes to produce it at 1/tick.

There's a huge array of Quantum Solar Panels powering the replicator itself, which combined with the large replicator energy buffer must have meant it had enough for each operation and could be refilled fast enough to keep the speed going. Overclockers don't scale linearly too, hence it only takes 31 to replicate iridium plates that quickly despite them taking more than 31 mb of UU.

I assume, that he put Items worth a lot of EU in the battery slot of the replicator and overfilled its internal buffer, which would also explain why that particular replicator received power, while the others didn't.