[R]Fuzzy C-Means, different between ppclust vs e1071?

Question

no. of cluster = 10, data points = 6000

library(ppclust)
cm <- fcm(x,centers = cen)

takes ~ 10 minutes

library(e1071)
cm <- cmeans(x,cen,1000)

takes ~ 1 minute

the only reason I prefer ppclust is because it allows nstart, meaning I am not stuck with local optima.

Given both are doing same thing, why is one taking 10x time then other?