Very slow symmetric encryption/decryption with GnuPG 2.X

[wurzelsepp1337 at web.de]

Hello
 

I use a Bashscript for Cloud-Encryption-Purposes under Debian Testing. It uses GnuPG for symmetrically encryption of many files with a for loop. With GnuPG 1.4.20, the encryption/decryption runs always very fast on my machine, but with GnuPG 2.X the speed is many many times slower. This process is really slow, I see the slow encryption/decryption of every (even small) single file.
 
Versions:
GnuPG 1.4.20
GnuPG 2.1.11 (even very slow with 2.0.X)
 
Commandline:
tar -cf - "$file" | gpg2 -z 0 --yes --batch --no-tty --symmetric --cipher-algo twofish --digest-algo sha512 --passphrase-file FILE -o /PATH/FILE
 
I've tested out that the RNG is not the problem. But even with "ln -s /dev/urandom /dev/random", the speed remains very slow.
Is there any way to analyse these performance differences? I've no idea.
But I think its better to use newer versions, when GnuPG 2.X represents the future.
 
Nick