Not sure where you saw it has a different flow rate. I forget when consumer switches went to asic rather than use processors. It has been a very long time though.
These type of devices can pass 1gbit up and 1gbit down on every port all at the same time. I doubt you come anywhere close to this limit. Now some switches with say 8-16 10gbit port you still have to read the fine print if they can run at those extremes.
I suspect the 305 is just a new model number.
Note unless you know why you need a managed switch save the money and buy the unit without the "e" on the end. There is not much use of these features in a home network.
i have some computer knowledge but stuff has accelerated to much in the last 15 years im completely dwarfed these days.
i got it from the netgear forums:
Early GS105Ev2 firmware release dates from 2013, first major update from November 2016.
Early GS308E firmware dates from March 2019. It's simply a new hardware model, probably initially intended for different sales channels.
"GS105E is End of Life. GS105E is a DHCP client.
GS305 is not. GS305E is."
Smart Managed Plus switches make an ideal upgrade from Unmanaged switches, with easy-to-use web browser-based management GUI, and essential Layer 2 switching features including VLAN, QoS, Multicast and Link Aggregation.
"GS305 has larger buffer memory/frame sizes than GS105 and better power performance." GS305E has this reduced power over 105e as well."
GS305 does not have DHCP because there is no IP stack as it's an unmanaged model. GS305E does have an IP stack, does support DHCP for address assignment (it's on the data sheet, too).
i understand some of that but not all of it.
as far as model numbers. the last digit is whether its a 5, 8 or 16 port.
1 is the old model. 2 is an older version with plastic shell. 3 is a metal shell that is the newest.
i basically use the older current one as a switch between my tv, ps4, hue lights and the router. i dont use it for any business purposes.