[mahyarm]

I think your 10s transaction is about equivalent to an unconfirmed bitcoin transaction or credit card authorization. How often is the actual bank-to-bank transfer?

The fact that there is an arbitrary money amount shows it's more of a fraud cutoff than a real limit.

[kpil]

It depends. The banks nets the transactions a number of times during the day, normally using a central bank.

In the mean time the credit on your account is debited a 'float' account that accumulates any debt to other banks or third party payment system. Each fast payment system also typically have a reserved amount deposited as a guarantee in the event that a bank runs out of money.

It's a real cost to reserve money so there is a restriction on the sums.

Can the central banks speed up the settlement? Yes probably, but it's a lot of work to do.

[joosters]

It's not the same. SEPA doesn't allow double-spends, unlike unconfirmed bitcoin transactions.