Post a Comment On: xdelta

Re: MS "Linker Version Info" in 3.0u

I can't explain this problem report *SEE BELOW*, indicating that Xdelta on Microsoft platforms is slower than the previous build by a factor of two.

?

Hello ... !

First of all I want to thank you for creating XDelta tool.
Realy nice and well documented stuff which sometimes helps a lot.
When I changed from v3.0t to v3.0u I've noticed some slowdown
in processing time. Well, it was just visual observation so I decided
to conduct a couple of tests. Here's what I've done.
Test was conducted on virtual memory disk using RAMDiskXP v2.0.0.100
from Cenatek Inc. It was done to exclude any impact from IO system.
Processing time was measured with Timer v8.00 tool by Igor Pavlov.
Test files size is about 275 MB. More exactly speaking 288 769 595
bytes for Test.dat.old and 288 771 262 bytes for Test.dat
Command line for XDelta is:
timer xdelta3 -v -9 -A= -B x -W x -I 0 -P x -s Test.dat.old Test.dat Diff.dat
where x is one of the values given below with the test results.

3.0t 3.0u
----- ----- --------------
16384 3.687 6.391 73.3% slower
65536 3.469 6.125 76.6% slower
1048576 2.578 5.453 111.5% slower
4194304 3.281 6.625 101.9% slower
8388608 3.953 7.718 95.2% slower

As you see v3.0u is averagely 91.7% SLOWER !!! I don't think it's a
some evil coincidence cause I redone every test twice. I have only one
clue. I see Linker Version Info in v3.0t exe-file is 8.0 while is 9.0
for the v3.0u exe-file so I suppose you changed or compilator itself
or its version.
I'll be very glad to hear from you.
Truly yours, ...