date: 2026-09-15T09:39:17Z
os: Darwin 25.2.0 arm64
macos: 26.2 (25C56)
cpu: Apple M4 Pro
logical cpus: 14
performance cores: 10  efficiency cores: 4  smt: none
P-core L1d: 131072 B  L2 (shared per cluster of 5): 16777216 B
E-core L1d: 65536 B  L2 (shared per cluster of 4): 4194304 B
cache line: 128 B  page: 16384 B  memory: 24 GiB
isa features: CRC32 FlagM FlagM2 FHM DotProd SHA3 RDM LSE SHA256 SHA512 SHA1 AES PMULL SB FRINTTS PACIMP LRCPC LRCPC2 FCMA JSCVT PAuth PAuth2 FPAC FPACCOMBINE DPB DPB2 BF16 I8MM WFxT RPRES ECV AFP LSE2 CSV2 CSV3 DIT FP16 BTI SME SME2 SME_F64F64 SME_I16I64 
power: 'AC Power'
load average at start: 10.21 8.24 8.04
frequency: not published by the vendor for this part; see estimated clock below
compiler: Apple clang version 17.0.0 (clang-1700.4.4.1)
kernel: Darwin Kernel Version 25.2.0: Tue Nov 18 21:09:56 PST 2025; root:xnu-12377.61.12~1/RELEASE_ARM64_T6041
boot args: none set
mitigation state: not exposed by macOS
estimated clock: 4.49 GHz (dependent 1-cycle add chain, 400000000 adds, min of 7 runs)
bench: QUICK=0 REPS=default CLOCK_GHZ=4.49
---
file /var/folders/t4/dv716g7154qc59jxlrdxyn_h0000gn/T//syscall-cost.wbGZy7/data  bytes 67108864  written and fsynced in 46 ms, read back and verified in 5 ms
read offset 33554432  reps 31 (plus 1 warmup, discarded)  clock 4.49 GHz
size 1 bytes: 65536 calls per rep
size 64 bytes: 65536 calls per rep
size 4096 bytes: 65536 calls per rep
size 65536 bytes: 4096 calls per rep
size 1048576 bytes: 256 calls per rep
RESULT clock 4.49 GHz
RESULT reps 31 runs
pread 1 B                                min      281.246  median      290.455  max      328.547  cv   3.1%  n 31  ns/call
RESULT pread_1_bytes 1 bytes
RESULT pread_1_calls 65536 calls/rep
RESULT pread_1_min 281.246 ns/call
RESULT pread_1_median 290.455 ns/call
RESULT pread_1_cv 3.09 percent
RESULT pread_1_nsbyte 281.24556 ns/byte
RESULT pread_1_cycles 1262.8 cycles/call
pread 64 B                               min      281.916  median      290.424  max      305.824  cv   2.0%  n 31  ns/call
RESULT pread_64_bytes 64 bytes
RESULT pread_64_calls 65536 calls/rep
RESULT pread_64_min 281.916 ns/call
RESULT pread_64_median 290.424 ns/call
RESULT pread_64_cv 1.96 percent
RESULT pread_64_nsbyte 4.40493 ns/byte
RESULT pread_64_cycles 1265.8 cycles/call
pread 4096 B                             min      313.670  median      320.944  max      342.719  cv   1.9%  n 31  ns/call
RESULT pread_4096_bytes 4096 bytes
RESULT pread_4096_calls 65536 calls/rep
RESULT pread_4096_min 313.670 ns/call
RESULT pread_4096_median 320.944 ns/call
RESULT pread_4096_cv 1.91 percent
RESULT pread_4096_nsbyte 0.07658 ns/byte
RESULT pread_4096_cycles 1408.4 cycles/call
pread 65536 B                            min     1257.192  median     1370.860  max     1527.669  cv   3.4%  n 31  ns/call
RESULT pread_65536_bytes 65536 bytes
RESULT pread_65536_calls 4096 calls/rep
RESULT pread_65536_min 1257.192 ns/call
RESULT pread_65536_median 1370.860 ns/call
RESULT pread_65536_cv 3.36 percent
RESULT pread_65536_nsbyte 0.01918 ns/byte
RESULT pread_65536_cycles 5644.8 cycles/call
pread 1048576 B                          min    20490.398  median    21189.293  max    22415.363  cv   1.5%  n 31  ns/call
RESULT pread_1048576_bytes 1048576 bytes
RESULT pread_1048576_calls 256 calls/rep
RESULT pread_1048576_min 20490.398 ns/call
RESULT pread_1048576_median 21189.293 ns/call
RESULT pread_1048576_cv 1.53 percent
RESULT pread_1048576_nsbyte 0.01954 ns/byte
RESULT pread_1048576_cycles 92001.9 cycles/call
memcpy 1 B                               min        1.108  median        1.209  max        1.286  cv   5.0%  n 31  ns/call
RESULT memcpy_1_bytes 1 bytes
RESULT memcpy_1_calls 65536 calls/rep
RESULT memcpy_1_min 1.108 ns/call
RESULT memcpy_1_median 1.209 ns/call
RESULT memcpy_1_cv 5.05 percent
RESULT memcpy_1_nsbyte 1.10817 ns/byte
RESULT memcpy_1_cycles 5.0 cycles/call
memcpy 64 B                              min        1.330  median        1.429  max        2.118  cv   9.2%  n 31  ns/call
RESULT memcpy_64_bytes 64 bytes
RESULT memcpy_64_calls 65536 calls/rep
RESULT memcpy_64_min 1.330 ns/call
RESULT memcpy_64_median 1.429 ns/call
RESULT memcpy_64_cv 9.15 percent
RESULT memcpy_64_nsbyte 0.02078 ns/byte
RESULT memcpy_64_cycles 6.0 cycles/call
memcpy 4096 B                            min       37.453  median       42.519  max       48.382  cv   5.2%  n 31  ns/call
RESULT memcpy_4096_bytes 4096 bytes
RESULT memcpy_4096_calls 65536 calls/rep
RESULT memcpy_4096_min 37.453 ns/call
RESULT memcpy_4096_median 42.519 ns/call
RESULT memcpy_4096_cv 5.17 percent
RESULT memcpy_4096_nsbyte 0.00914 ns/byte
RESULT memcpy_4096_cycles 168.2 cycles/call
memcpy 65536 B                           min      519.897  median      546.021  max      599.436  cv   4.2%  n 31  ns/call
RESULT memcpy_65536_bytes 65536 bytes
RESULT memcpy_65536_calls 4096 calls/rep
RESULT memcpy_65536_min 519.897 ns/call
RESULT memcpy_65536_median 546.021 ns/call
RESULT memcpy_65536_cv 4.17 percent
RESULT memcpy_65536_nsbyte 0.00793 ns/byte
RESULT memcpy_65536_cycles 2334.3 cycles/call
memcpy 1048576 B                         min    11197.266  median    12204.750  max    12880.859  cv   2.5%  n 31  ns/call
RESULT memcpy_1048576_bytes 1048576 bytes
RESULT memcpy_1048576_calls 256 calls/rep
RESULT memcpy_1048576_min 11197.266 ns/call
RESULT memcpy_1048576_median 12204.750 ns/call
RESULT memcpy_1048576_cv 2.53 percent
RESULT memcpy_1048576_nsbyte 0.01068 ns/byte
RESULT memcpy_1048576_cycles 50275.7 cycles/call
getppid                                  min       83.148  median       87.238  max       89.345  cv   1.6%  n 31  ns/call
RESULT getppid_bytes 0 bytes
RESULT getppid_calls 65536 calls/rep
RESULT getppid_min 83.148 ns/call
RESULT getppid_median 87.238 ns/call
RESULT getppid_cv 1.65 percent
RESULT getppid_cycles 373.3 cycles/call
clock_gettime MONOTONIC_RAW              min       12.201  median       12.686  max       13.100  cv   2.2%  n 31  ns/call
RESULT clock_gettime_bytes 0 bytes
RESULT clock_gettime_calls 65536 calls/rep
RESULT clock_gettime_min 12.201 ns/call
RESULT clock_gettime_median 12.686 ns/call
RESULT clock_gettime_cv 2.24 percent
RESULT clock_gettime_cycles 54.8 cycles/call
pread: fixed cost 281.3 ns (intercept over 1, 64, 4096 B), slope 0.00790 ns/byte there; copy slope 0.01957 ns/byte between 65536 and 1048576 B
memcpy: fixed cost 0.9 ns (intercept over 1, 64, 4096 B), slope 0.00892 ns/byte there; copy slope 0.01086 ns/byte between 65536 and 1048576 B
RESULT pread_fixed 281.3 ns
RESULT pread_small_slope 0.00790 ns/byte
RESULT pread_copy_slope 0.01957 ns/byte
RESULT memcpy_fixed 0.9 ns
RESULT memcpy_small_slope 0.00892 ns/byte
RESULT memcpy_copy_slope 0.01086 ns/byte
RESULT pread_fixed_cycles 1263 cycles
RESULT clock_checksum 1114345161822424 sum
checksums: every pread and memcpy pass matched its reference sum and the source bytes; every getppid returned the parent pid
