variadic performance hit

ow.cljc

(deftype Vec3 [x y z])

(defn vec3+
  [a b]
  (Vec3. (+ (.-x a) (.-x b))
         (+ (.-y a) (.-y b))
         (+ (.-z a) (.-z b))))

(defn vec3+v
  ([a b]
   (Vec3. (+ (.-x a) (.-x b))
          (+ (.-y a) (.-y b))
          (+ (.-z a) (.-z b))))
  ([a b c]
   (Vec3. (+ (.-x a) (.-x b) (.-x c))
          (+ (.-y a) (.-y b) (.-y c))
          (+ (.-z a) (.-z b) (.-z c)))))

(defn bench[]  ;; "Elapsed time: 7.300000 msecs"
  (time (dotimes [x 1000000]
          (vec3+ (Vec3. 1 2 3)
                 (Vec3. 4 5 6)))))

(defn bench-v[] ;; "Elapsed time: 105.700000 msecs"
  (time (dotimes [x 1000000]
          (vec3+v (Vec3. 1 2 3)
                  (Vec3. 4 5 6)))))