Is Hardware needed by June SoftLaunch or only July Launch

I am not clear if I should start ordering hardware now to be ready for June 1 Soft Launch, or to wait a bit longer and be ready for the July Launch?

I’ll first try to run the beta on slighly older h/w as long as it can deliver the performance. I figure in testing the number of transactions and therefore resource requirements may not be as high.
But if necessary I’ll buy better hardware sooner.