问为什么带有P-256(​NIST曲线P-256/​SHA-256)曲线的ECDSA符号比其它曲线要快得多？

EN

./openssl speed -elapsed ecdsa

OpenSSL 1.1.1n  15 Mar 2022
built on: Fri Jul 29 08:48:14 2022 UTC
options:bn(64,64) rc4(16x,int) des(int) aes(partial) idea(int) blowfish(ptr) 
compiler: gcc -fPIC -pthread -m64 -Wa,--noexecstack -Wall -O3 -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 -DZLIB -DNDEBUG
                              sign    verify    sign/s verify/s
 160 bits ecdsa (secp160r1)   0.0002s   0.0002s   4916.7   4923.6
 192 bits ecdsa (nistp192)   0.0003s   0.0002s   3936.7   4184.7
 224 bits ecdsa (nistp224)   0.0004s   0.0003s   2672.5   2960.2
 256 bits ecdsa (nistp256)   0.0000s   0.0001s  42865.3  13915.1
 384 bits ecdsa (nistp384)   0.0010s   0.0008s   1027.2   1281.3
 521 bits ecdsa (nistp521)   0.0022s   0.0017s    444.8    582.7
 163 bits ecdsa (nistk163)   0.0003s   0.0005s   3938.3   1969.7
 233 bits ecdsa (nistk233)   0.0004s   0.0007s   2825.4   1428.3
 283 bits ecdsa (nistk283)   0.0006s   0.0012s   1680.2    851.9
 409 bits ecdsa (nistk409)   0.0010s   0.0019s    998.3    523.9
 571 bits ecdsa (nistk571)   0.0022s   0.0042s    462.3    239.6
 163 bits ecdsa (nistb163)   0.0003s   0.0005s   3677.1   1862.8
 233 bits ecdsa (nistb233)   0.0004s   0.0007s   2699.5   1343.3
 283 bits ecdsa (nistb283)   0.0006s   0.0012s   1570.0    805.3
 409 bits ecdsa (nistb409)   0.0011s   0.0020s    942.2    495.5
 571 bits ecdsa (nistb571)   0.0023s   0.0045s    432.2    224.7

Operating Sytem: Ubuntu 16.04 LTS
Memory: 15.4 GiB
Processor: Intel® Core™ i7-7500U CPU @ 2.70GHz × 4