Tech Support Forum - View Single Post - MD5 of a file is different on different computers?

matt99b · 06-17-2009, 04:46 AM

Is this possible? It is the same file.

I have a few .rar files, and I want to distribute it online. I want to check that the MD5 is indeed the same on every computer (as people claim), so that I can provide it on my website as a means of checking the integrity of the files. Each file is very large (1GB). I have copied them to 5 different computers, and 2 of the computers are giving a different MD5 result to the other 3 computers.

On Macbok Pro, OS X:
MD5 (test.part1.rar) = 84cc656767f52708a7d491e80b9153a7
MD5 (test.part2.rar) = ecc5f0f3939112d533321679329d35c0

On PC Laptop, Windows XP:
test.part1.rar = 84CC656767F52708A7D491E80B9153A7
test.part2.rar = ECC5F0F3939112D533321679329D35C0

On Mac Pro, OS X:
test.part1.rar = 84CC656767F52708A7D491E80B9153A7
test.part2.rar = ECC5F0F3939112D533321679329D35C0

----

Desktop PC, Windows XP:
test.part1.rar = 527C6E130835387DA8DE7F343CC5CE54
test.part2.rar = A38857B949E390CEC7AE096B7B7B42CA

On 2nd Laptop, OS X:
test.part1.rar = 527C6E130835387DA8DE7F343CC5CE54
test.part2.rar = A38857B949E390CEC7AE096B7B7B42CA

----

So, why would the MD5 be different? I thought it was meant to be the same on all machines?

I've copied the files many many times, via network, and DVD, to check that it is copied correctly. Indeed it is the same result every time. It does unrar correctly without errors on all machines. Indeed the above MD5 results are consistent and remain unchanged.

Can anyone shed any light on this? Is the MD5 check not quite what we believe it to be?

06-17-2009, 04:46 AM	#1 (permalink)
matt99b Registered User Join Date: Apr 2008 Posts: 13 OS: win xp	MD5 of a file is different on different computers? Is this possible? It is the same file. I have a few .rar files, and I want to distribute it online. I want to check that the MD5 is indeed the same on every computer (as people claim), so that I can provide it on my website as a means of checking the integrity of the files. Each file is very large (1GB). I have copied them to 5 different computers, and 2 of the computers are giving a different MD5 result to the other 3 computers. On Macbok Pro, OS X: MD5 (test.part1.rar) = 84cc656767f52708a7d491e80b9153a7 MD5 (test.part2.rar) = ecc5f0f3939112d533321679329d35c0 On PC Laptop, Windows XP: test.part1.rar = 84CC656767F52708A7D491E80B9153A7 test.part2.rar = ECC5F0F3939112D533321679329D35C0 On Mac Pro, OS X: test.part1.rar = 84CC656767F52708A7D491E80B9153A7 test.part2.rar = ECC5F0F3939112D533321679329D35C0 ---- Desktop PC, Windows XP: test.part1.rar = 527C6E130835387DA8DE7F343CC5CE54 test.part2.rar = A38857B949E390CEC7AE096B7B7B42CA On 2nd Laptop, OS X: test.part1.rar = 527C6E130835387DA8DE7F343CC5CE54 test.part2.rar = A38857B949E390CEC7AE096B7B7B42CA ---- So, why would the MD5 be different? I thought it was meant to be the same on all machines? I've copied the files many many times, via network, and DVD, to check that it is copied correctly. Indeed it is the same result every time. It does unrar correctly without errors on all machines. Indeed the above MD5 results are consistent and remain unchanged. Can anyone shed any light on this? Is the MD5 check not quite what we believe it to be? Last edited by matt99b; 06-17-2009 at 04:50 AM.