a data point on a machine from 2014: $ ./aestest -l BearSSL aes_ct Intel SSE2 bitsliced
$ progress -f /dev/zero sh -c 'exec ./aestest -e -b 256 -c aes-xts -i "Intel SSE2 bitsliced" > /dev/null' 399 MiB 56.98 MiB/s ^C $ progress -f /dev/zero sh -c 'exec ./aestest -e -b 256 -c aes-xts -i "BearSSL aes_ct" > /dev/null' 211 MiB 26.38 MiB/s ^C $ progress -f /dev/zero sh -c 'exec ./bad -e -b 256 -c aes-xts > /dev/null' 869 MiB 86.85 MiB/s ^C So the sse2 is slower, but not enough to get upset about. cpu0: "Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz" cpu0: Intel Core i7, Xeon 34xx, 35xx and 55xx (Nehalem) (686-class), 2800.09 MHz cpu0: family 0x6 model 0x1a stepping 0x5 (id 0x106a5) cpu0: features 0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE> cpu0: features 0xbfebfbff<MCA,CMOV,PAT,PSE36,CLFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2> cpu0: features 0xbfebfbff<SS,HTT,TM,SBF> cpu0: features1 0x98e3bd<SSE3,DTES64,MONITOR,DS-CPL,VMX,EST,TM2,SSSE3,CX16> cpu0: features1 0x98e3bd<xTPR,PDCM,SSE41,SSE42,POPCNT> cpu0: features2 0x28100800<SYSCALL/SYSRET,XD,RDTSCP,EM64T> cpu0: features3 0x1<LAHF> cpu0: features7 0x9c000000<IBRS,STIBP,L1D_FLUSH,SSBD>
