Even more obvious with GCM cipher:
root@routegateway:~# openssl speed -elapsed -evp aes-128-gcm
You have chosen to measure elapsed time instead of user CPU time.
Doing aes-128-gcm for 3s on 16 size blocks: 64818679 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 64 size blocks: 40327930 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 256 size blocks: 20244667 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 1024 size blocks: 8163187 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 8192 size blocks: 1284854 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 16384 size blocks: 654175 aes-128-gcm's in 3.00s
OpenSSL 1.1.1g 21 Apr 2020
built on: Sun Aug 2 16:16:00 2020 UTC
options:bn(64,64) rc4(16x,int) des(int) aes(partial) blowfish(ptr)
compiler: x86_64-openwrt-linux-musl-gcc -fPIC -pthread -m64 -Wa,--noexecstack -Wall -O3 -pipe -fno-caller-saves -fno-plt -fhonour-copts -Wno-error=unused-but-set-variable -Wno-error=unused-result -Wformat -Werror=format-security -fstack-protector -D_FORTIFY_SOURCE=1 -Wl,-z,now -Wl,-z,relro -O3 -fpic -ffunction-sections -fdata-sections -znow -zrelro -DOPENSSL_USE_NODELETE -DL_ENDIAN -DOPENSSL_PIC -DOPENSSL_CPUID_OBJ -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DKECCAK1600_ASM -DRC4_ASM -DMD5_ASM -DAESNI_ASM -DVPAES_ASM -DGHASH_ASM -DECP_NISTZ256_ASM -DX25519_ASM -DPOLY1305_ASM -DNDEBUG
The 'numbers' are in 1000s of bytes per second processed.
type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes 16384 bytes
aes-128-gcm 345699.62k 860329.17k 1727544.92k 2786367.83k 3508507.99k 3572667.73k
root@routegateway:~# OPENSSL_ia32cap="~0x200000200000000" openssl speed -elapsed -evp aes-128-gcm
You have chosen to measure elapsed time instead of user CPU time.
Doing aes-128-gcm for 3s on 16 size blocks: 19441905 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 64 size blocks: 5798100 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 256 size blocks: 1517519 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 1024 size blocks: 385739 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 8192 size blocks: 48473 aes-128-gcm's in 3.00s
Doing aes-128-gcm for 3s on 16384 size blocks: 24269 aes-128-gcm's in 3.00s
OpenSSL 1.1.1g 21 Apr 2020
built on: Sun Aug 2 16:16:00 2020 UTC
options:bn(64,64) rc4(16x,int) des(int) aes(partial) blowfish(ptr)
compiler: x86_64-openwrt-linux-musl-gcc -fPIC -pthread -m64 -Wa,--noexecstack -Wall -O3 -pipe -fno-caller-saves -fno-plt -fhonour-copts -Wno-error=unused-but-set-variable -Wno-error=unused-result -Wformat -Werror=format-security -fstack-protector -D_FORTIFY_SOURCE=1 -Wl,-z,now -Wl,-z,relro -O3 -fpic -ffunction-sections -fdata-sections -znow -zrelro -DOPENSSL_USE_NODELETE -DL_ENDIAN -DOPENSSL_PIC -DOPENSSL_CPUID_OBJ -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DKECCAK1600_ASM -DRC4_ASM -DMD5_ASM -DAESNI_ASM -DVPAES_ASM -DGHASH_ASM -DECP_NISTZ256_ASM -DX25519_ASM -DPOLY1305_ASM -DNDEBUG
The 'numbers' are in 1000s of bytes per second processed.
type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes 16384 bytes
aes-128-gcm 103690.16k 123692.80k 129494.95k 131665.58k 132363.61k 132541.10k