Slow SSHFS speed

[MarkChang]

Dear all,

i have been using Armbian bionic currently running kernel 4.4.156-rockchip64, for sharing files over the internet, i am currently using sshfs. Openssl benchmark ls as followed
 

OpenSSL 1.1.0g  2 Nov 2017
built on: reproducible build, date unspecified
options:bn(64,64) rc4(char) des(int) aes(partial) blowfish(ptr)
compiler: gcc -DDSO_DLFCN -DHAVE_DLFCN_H -DNDEBUG -DOPENSSL_THREADS -DOPENSSL_NO_STATIC_ENGINE -DOPENSSL_PIC -DOPENSSL_BN_ASM_MONT -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DVPAES_ASM -DECP_NISTZ256_ASM -DPOLY1305_ASM -DOPENSSLDIR="\"/usr/lib/ssl\"" -DENGINESDIR="\"/usr/lib/aarch64-linux-gnu/engines-1.1\""
The 'numbers' are in 1000s of bytes per second processed.
type             16 bytes     64 bytes    256 bytes   1024 bytes   8192 bytes  16384 bytes
aes-256-cbc      89554.02k   252995.50k   458589.18k   588922.54k   641851.39k   637659.82k

However, when it comes to sshfs speeds, i can only reach around 20-25MBytes per second

> fallocate -l 1G /tmp/largefile
> pv /tmp/largefile > /srv/tmp/test_largefile
1.00GiB 0:00:46 [22.0MiB/s] [==============================================================================================================================================>] 100%

Do i need AF_ALG to actually speedup sshfs speed? or is this board not fast enough to achieve higher sshfs speeds?
Note : the cpu loading is not that high on sshfs copying
Thanks a lot for your help

[jmandawg]

over scp, i average around 30-35MBs:

root@chromebox:/home/jmandawg# scp random500MBfile renegade:/mnt/data/
root@renegade's password: 
random500MBfile                               100%  500MB  31.5MB/s   00:15