"performs the same function as" is correct and usable in written English.
You can use it when you need to compare two or more things or activities and describe how they are alike. For example: "The Wright brothers' plane performed the same function as modern aircraft; it allowed people to travel by air."
In her project, the grid of steel mullions performs the same function as Johnson's period windows.
During daylight hours it performs the same function as any other cigar store on a busy corner.
The chip performs the same function as the magnetic strip on the back of a credit card, storing account information and other data necessary to make a purchase.
The loudspeaker performs the same function as the earphone of the telephone receiver but is required to displace a larger volume of air.
In the given example, the human nervous system is simply a physical system, a specific assembly of particles, which performs the same function as one of these devices, if no other such device interacts with the photons before the human observer does.
The Hydrojet Cutter is a fine high-pressure jet of water, which essentially performs the same function as the ultrasound aspirator.
A motel performs the same functions as a hotel but in a format designed for travelers using automobiles.
The arc is completely enclosed by the flux so that a high current can be used without the risk of air entrainment or severe spatter but otherwise the flux performs the same functions as the flux in manual metal arc welding.
The chloroplast Sar1 homologue is probably a GTPase, but whether it performs the same functions as Sar1 appears less certain.
Sociologically, "I think papal trips perform the same function as gay pride parades," Mr. Allen said.
But General O'Reilly stressed that the Russian radar was not designed to perform the same function as the American radar proposed for the Czech Republic.
