Does such a product exist? The ATX 24 pin connector has the right voltages for SATA (5V plus 12V, but modern drives only need 5V). I have a proprietary PSU on an Acer EasyStore H340 NAS which only ...

An ATX power supply unit, or PSU, has a 24-pin connector for energy delivery. ... The 24-pin connector plug on the PSU has one green wire and a number of black wires.

The ATX Breakout board V2.0 is compatible with 20 pin and 24 pin power supplies, there is also an extra 4 pin connector to take advantage of the 12V CPU Power for extra current output.