scp speeds

so i was scp’ing some files across my network when i realized that there is / was something wronf with the speeds at which the transfers were occuring.

here is what i learned

we will create a test file to copy around the network (not to big or it will take forever but not to small so it can average out):
$ dd if=/dev/zero of=test500M bs=1M count=500

now lets get some numbers:

user@uranus ~ $ scp test500M user@titan:/mnt/HD_b2/
user@titan's password:
test500M                                  100%  500MB   2.2MB/s   03:44

UGH!!!! – wtf ??

user@uranus ~ $ scp -c blowfish test500M user@titan:/mnt/HD_b2/
user@titan's password:
test500M                                  100%  500MB   3.6MB/s   02:21

okay – a little better

user@uranus ~ $ scp -C test500M user@titan:/mnt/HD_b2/
user@titan's password:
test500M                                  100%  500MB   8.6MB/s   00:58

okay – way better

user@uranus ~ $ scp -C -c blowfish test500M user@titan:/mnt/HD_b2/
user@titan's password:
test500M                                  100%  500MB   9.4MB/s   00:53

now we are cranking on all gears

i tested arcfour cipher also with similar results to blowfish

so with those tests i have learned 2 things:
1) keep compression enabled
2) always use a lighter cipher when encryption is not critical