Hi Athanasios,
SRW224G4P-K9 allocates POE power according to the power budget mentioned in the datasheet..
datasheet says the SG300-24P (order p/n SRW224G4P ) has a power budget of 180W
180W / 24 ports = 7.5W per port
But uour answer is both.
SRW224G4P will "give 7.5W to all ports simultaneously or 15W to only 12 ports" if that's what you want to do.
There is the newly introduced 500 series switches that will do for example;
order p/n SG500X-24P-K9 with 24 POE ports has a POE power budget of 375W or 375w / 24ports = 15W per port
regards Dave