Planning to checksum in PHP?

I am rewriting NINJA to use the block scanning part of the rsync algorithm for binary differences, so I needed to figure out which checksum would be fastest to achieve in PHP. rsync normally calls for Adler-32, but any checksum algorithm should work fine.

Below are the results of several checksum/hash algorithms in PHP. Clearly, PHP’s native crc32() function is the fastest of the group:

This is a test to calculate which checksum/hashing algorithm is fastest.
Testing with a 0x100 size block: crc16() : Completed in 0.00100493431091s : 8d4d crc32() : Completed in 0.00001001358032s : 7c1e625b adler32(): Completed in 0.00113701820374s : 490d172b md5() : Completed in 0.00002098083496s : 0fe9cb3c5543066446bf35256be6d075 sha1() : Completed in 0.00003004074096s : 8a757300390b89df6f0f57f69d5b90b064dd4544 Testing with a 0x200 size block: crc16() : Completed in 0.00193786621094s : 72e5 crc32() : Completed in 0.00000905990600s : e37842fa adler32(): Completed in 0.00049519538879s : 25c52566 md5() : Completed in 0.00001502037048s : d78e366baf1b9cac702b25fcc8f29bf9 sha1() : Completed in 0.00001811981201s : 67dde897fc9cc0fcb2408f620b933a038060cfe0 Testing with a 0x400 size block: crc16() : Completed in 0.00572681427002us : ea94 crc32() : Completed in 0.00001215934753s : d90ebae3 adler32(): Completed in 0.00187897682190s : dd9549f1 md5() : Completed in 0.00001978874206s : c39ea5f986407208be72f6583bd33cc5 sha1() : Completed in 0.00002598762512s : fb35563f478ac896136323c44354d0bae7ce8f84 Testing with a 0x800 size block: crc16() : Completed in 0.00884294509888s : f1be crc32() : Completed in 0.00001597404479s : 991e35aa adler32(): Completed in 0.00279593467712s : 1b8aa5d0 md5() : Completed in 0.00002598762512s : 565d6a496a9eaae0d20b82167077cd20 sha1() : Completed in 0.00006914138793s : 3a182383312c801a54d101b29382ebdb2fa15f3c Testing with a 0x1000 size block: crc16() : Completed in 0.01928710937500s : 3f4b crc32() : Completed in 0.00002408027648s : a68c1fb3 adler32(): Completed in 0.00396609306335s : e3483428 md5() : Completed in 0.00003981590271s : 6b3343ca4a23b9b536cd9bd15aed55ea sha1() : Completed in 0.00098609924316s : 3ce01647efb6454f75df17db5903f4e3caab8802 Testing with a 0x2000 size block: crc16() : Completed in 0.03786110877990s : cc79 crc32() : Completed in 0.00004100799560s : 7d1cf85 adler32(): Completed in 0.00977802276611s : e7c44c66 md5() : Completed in 0.00006699562072s : eabca26813c7bdcae89a369e855dfd2c sha1() : Completed in 0.00009417533874s : 191d4a5803981f499440a144c60247ca18069962 Testing with a 0x4000 size block: crc16() : Completed in 0.08212399482730s : 57b6 crc32() : Completed in 0.00007605552673s : 11dfafc9 adler32(): Completed in 0.01928615570070s : f9db9b2e md5() : Completed in 0.00012612342834s : 7ebbe8b9c97854f4c17c5671aaedd2db sha1() : Completed in 0.00017595291137s : b482c1279333ac896a0bc9f0ba04719d8d4aad04 Testing with a 0x8000 size block: crc16() : Completed in 0.15789103508000s : 2e40 crc32() : Completed in 0.00014996528625s : b383f65c adler32(): Completed in 0.03803014755250s : bdb63537 md5() : Completed in 0.00022792816162s : d29cce15e12b0753b7f015ee004e54c8 sha1() : Completed in 0.00033116340637s : 67f323e6f111004f8323298928171d8bda9bee49
Testing with a 0x10000 size block: crc16() : Completed in 0.31415820121800s : 6f91 crc32() : Completed in 0.00027489662170s : f50d27d7 adler32(): Completed in 0.07920503616330s : a8391752 md5() : Completed in 0.00044894218444s : 131cb4ff2f30b5a3d311fa3ae1fcae6a sha1() : Completed in 0.00065088272094s : 011d57064caea04506ecae2fcdbb8c29c4a5ddb6