sha256 vs sha512

➜  ~ openssl speed sha256 sha512
To get the most accurate results, try to run this
program when this computer is idle.
Doing sha256 for 3s on 16 size blocks: 4524013 sha256's in 2.65s
Doing sha256 for 3s on 64 size blocks: 2538054 sha256's in 2.62s
Doing sha256 for 3s on 256 size blocks: 1179898 sha256's in 2.64s
Doing sha256 for 3s on 1024 size blocks: 360805 sha256's in 2.60s
Doing sha256 for 3s on 8192 size blocks: 51451 sha256's in 2.66s
Doing sha512 for 3s on 16 size blocks: 3500317 sha512's in 2.65s
Doing sha512 for 3s on 64 size blocks: 3257795 sha512's in 2.58s
Doing sha512 for 3s on 256 size blocks: 1515417 sha512's in 2.64s
Doing sha512 for 3s on 1024 size blocks: 555108 sha512's in 2.64s
Doing sha512 for 3s on 8192 size blocks: 81725 sha512's in 2.64s
OpenSSL 0.9.8zh 14 Jan 2016
built on: Jan 23 2017
options:bn(64,64) md2(int) rc4(ptr,char) des(idx,cisc,16,int) aes(partial) blowfish(idx)
compiler: -arch x86_64 -fmessage-length=0 -pipe -Wno-trigraphs -fpascal-strings -fasm-blocks -O3 -D_REENTRANT -DDSO_DLFCN -DHAVE_DLFCN_H -DL_ENDIAN -DMD32_REG_T=int -DOPENSSL_NO_IDEA -DOPENSSL_PIC -DOPENSSL_THREADS -DZLIB -mmacosx-version-min=10.6
available timing options: TIMEB USE_TOD HZ=100 [sysconf value]
timing function used: getrusage
The 'numbers' are in 1000s of bytes per second processed.
type             16 bytes     64 bytes    256 bytes   1024 bytes   8192 bytes
sha256           27365.21k    62047.81k   114524.80k   142162.35k   158232.26k
sha512           21099.80k    80751.73k   146928.32k   215369.03k   253480.51k