How to compare two big (!) binary files if equal or not?

[mattad]

Assume I have 2 big binary files (e.g. > 400 MB). I want to test (only) if they are equal or not.

When I open now UltraCompare and drag the first file onto the pane then UC starts to compare
it with the other (currently empty) file. This takes a long, long time and is useless.

How can I tell UC to wait until I dragged the second files onto UC as well?

Furthermore it seems to me that UC tries (in general) not only to find out if two files are equal or not
but what are the differences. That is fine but in my case not necessary.
Finding out if equal or not should be much, much faster.

I could imagine that there is an option which speeds up this comparison operation by only test on equalness.
How do I do that?

Matt

[pietzcker]

You could use the UC shell extension (select both files in Windows Explorer and then run Ultracompare from the (right-click) context menu) so it will load both files right from the start.

If you had the two files in different directories (as the only files there) you could do a directory compare where you have the option of doing a simple compare (just compare dates and file sizes) or a "real" compare but not list the actual differences unless you then switch to file compare.

Or just use the DOS command fc (http://www.computerhope.com/fchlp.htm)

Or - the best and fastest solution: Compare the two files' MD5 or other checksums. If they are equal, the files are equal. Use HashTab as an extension to Windows Explorer: http://www.beeblebrox.org/hashtab/index.php

HTH,
Tim

[Aqualung]

You could use the UC shell extension (select both files in Windows Explorer and then run Ultracompare from the (right-click) context menu) so it will load both files right from the start.

Myeah, no need for UC: go about comparing hashes.