So, I've looked around for other people's implementations (to save time) and wrote a quick benchmark.

We'll start with the slowest and get to the quickest.

1. ArrayEqualCompare Taken from here.

public bool Compare(byte[] array1, byte[] array2) { return (array1 as IStructuralEquatable).Equals(array2,StructuralComparisons.StructuralEqualityComparer); }

2. SequenceEqualCompare

public bool Compare(byte[] array1, byte[] array2) { return Enumerable.SequenceEqual(array1, array2); }

3.SimpleCompare

public bool Compare(byte[] a1, byte[] a2) { if (a1.Length != a2.Length) return false; for (int i = 0; i < a1.Length; i++) if (a1[i] != a2[i]) return false; return true; }

4. unsafeByteCompare Taken from here.

public unsafe bool Compare(byte[] a, byte[] b) { if (a.Length != b.Length) return false; int len = a.Length; unsafe { fixed (byte* ap = a, bp = b) { int* aip = (int*)ap, bip = (int*)bp; for (; len >= 4; len -= 4) { if (*aip != *bip) return false; aip++; bip++; } byte* ap2 = (byte*)aip, bp2 = (byte*)bip; for (; len > 0; len--) { if (*ap2 != *bp2) return false; ap2++; bp2++; } } } return true; }

5. unsafeIntCompare Taken from here.

public unsafe bool Compare(byte[] b1, byte[] b2) { if (b1 == b2) return true; if (b1 == null || b2 == null) return false; if (b1.Length != b2.Length) return false; int len = b1.Length; fixed (byte* p1 = b1, p2 = b2) { int* i1 = (int*)p1; int* i2 = (int*)p2; while (len >= 4) { if (*i1 != *i2) return false; i1++; i2++; len -= 4; } byte* c1 = (byte*)i1; byte* c2 = (byte*)i2; while (len > 0) { if (*c1 != *c2) return false; c1++; c2++; len--; } } return true; }

6. unsafeSvensonCompare Taken from here.

[ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)] public unsafe bool Compare(byte[] strA, byte[] strB) { int length = strA.Length; if (length != strB.Length) { return false; } fixed (byte* str = strA) { byte* chPtr = str; fixed (byte* str2 = strB) { byte* chPtr2 = str2; byte* chPtr3 = chPtr; byte* chPtr4 = chPtr2; while (length >= 10) { if ((((*(((int*)chPtr3)) != *(((int*)chPtr4))) || (*(((int*)(chPtr3 + 2))) != *(((int*)(chPtr4 + 2))))) || ((*(((int*)(chPtr3 + 4))) != *(((int*)(chPtr4 + 4)))) || (*(((int*)(chPtr3 + 6))) != *(((int*)(chPtr4 + 6)))))) || (*(((int*)(chPtr3 + 8))) != *(((int*)(chPtr4 + 8))))) { break; } chPtr3 += 10; chPtr4 += 10; length -= 10; } while (length > 0) { if (*(((int*)chPtr3)) != *(((int*)chPtr4))) { break; } chPtr3 += 2; chPtr4 += 2; length -= 2; } return (length <= 0); } } }

7. unsafeCompare Taken from here.

public unsafe bool Compare(byte[] a1, byte[] a2) { if (a1 == null || a2 == null || a1.Length != a2.Length) return false; fixed (byte* p1 = a1, p2 = a2) { byte* x1 = p1, x2 = p2; int l = a1.Length; for (int i = 0; i < l / 8; i++, x1 += 8, x2 += 8) if (*((long*)x1) != *((long*)x2)) return false; if ((l & 4) != 0) { if (*((int*)x1) != *((int*)x2)) return false; x1 += 4; x2 += 4; } if ((l & 2) != 0) { if (*((short*)x1) != *((short*)x2)) return false; x1 += 2; x2 += 2; } if ((l & 1) != 0) if (*((byte*)x1) != *((byte*)x2)) return false; return true; } }

8. unsafeLongCompare taken from Here.

public unsafe bool Compare(byte[] a, byte[] b) { if (a.Length != b.Length) return false; int len = a.Length; unsafe { fixed (byte* ap = a, bp = b) { long* alp = (long*)ap, blp = (long*)bp; for (; len >= 8; len -= 8) { if (*alp != *blp) return false; alp++; blp++; } byte* ap2 = (byte*)alp, bp2 = (byte*)blp; for (; len > 0; len--) { if (*ap2 != *bp2) return false; ap2++; bp2++; } } } return true; }

9. memcmpCompare Taken from here.

[DllImport("msvcrt.dll", CallingConvention = CallingConvention.Cdecl)] static extern int memcmp(byte[] b1, byte[] b2, long count); public bool Compare(byte[] b1, byte[] b2) { // Validate buffers are the same length. // This also ensures that the count does not exceed the length of either buffer. return b1.Length == b2.Length && memcmp(b1, b2, b1.Length) == 0; }

You can find the test project at

https://github.com/drorgl/ForBlog/tree/master/CompareByteArray

And the benchmarks at

http://uhurumkate.blogspot.com/p/byte-array-comparison-benchmarks.html

Hello! I cannot find the benchmark results anywhere... ??

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