LAN data transfer speed

Hello experts!
I would appreciate your answers to the following questions!
I found information on the Wiznet website that the w5500 chip supports LAN data transfer speeds of 15Mbps. Is this speed divided between 8 sockets and less than 2Mbps per socket if all 8 simultaneously receive and transmit data? Why the PMODE configuration - 1xx 100M and fast SPI 80Mbps, if the limit is 15Mbps? Moreover, the chip heats up to 55C at high speed (whose chip is cold?). Should the chip heat up to such a temperature at maximum speeds without a heat sink?
I need a data transfer speed of about 100Mbps, should I consider the w5300 chip for this?