DSA, RSA, ECDSA etc - which one is cheapest for signing?
From these three, ECDSA is faster - it does arithmetic with smaller numbers, and is thus faster. (RSA verification is faster than ECDSA, even though it uses larger numbers, because it computes a exponentiation by a small number.)

Still, elliptic curve Schnorr signature should be around 5-10% faster than ECDSA (or even more in a side-channel resistant implementation) since it does not require an inversion modulo the curve order. And as mentioned, there is also Ed25519, which uses a special, non-standard curve in order to be more efficient.