This is mainly in reference to the fact that Reserved Instances don't have any bearing on the instances themselves (ie. no code change, performance chance, server downtime, etc.).
The 57% savings is the difference between the 3-year, no-upfront, standard Reserved Instance rate and the On-demand rate (for RDS it is 30% vs on-demand)
As far as compute savings plans:
1-yr SP is anywhere from 26-29% savings vs on-demand
3-year Sp is anywhere from 49-52% savings vs on-demand
... but note that these commitments are non-transferrable. Customers find our tailorable commitments to be a healthy blend of savings + safety against over-committing to volume they may not need
The 57% savings is the difference between the 3-year, no-upfront, standard Reserved Instance rate and the On-demand rate (for RDS it is 30% vs on-demand)
As far as compute savings plans:
1-yr SP is anywhere from 26-29% savings vs on-demand
3-year Sp is anywhere from 49-52% savings vs on-demand
... but note that these commitments are non-transferrable. Customers find our tailorable commitments to be a healthy blend of savings + safety against over-committing to volume they may not need