It can be its possible to speed up up to 10% or so on. If I remember right, I read like this on this gl forum on last weeks, by replace or add one of new more secure and about 10% faster chipper (with or with other eliptic courve?) suite for Open VPN.
If its true, you can hope to speed up your Open VPN from 8,5MB to 9,35MB.
It can be one other will find the link by the search function:
By the way, thats remember me on on old possible open chipper suite question from old deleted bug tracker. I open the fllow discussion for this: