can someone tell me, in wich cases LZMA2 is better than LZMA?
I´ve compressed some files with both to test the filesize. Some files with LZMA2 are a bit bigger than with LZMA. (most times ISO files)
Thx
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there is no black magic: single-threaded algorithm can't be executed without modifications by many threads. and these changes sometimes means less compression, trading speed vs size
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unfortunately, that's impossible with current algos. for people compressing gigabytes of data loss of comprssion ratio will be not so huge and not so important
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For LZMA2 in normal/max/ultra level:
2 threads provides almost the same compression ratio as with 1 threads.
If you set 3 threads, LZMA2 still use 2 threads.
4 and more threads give worse compression ratio.
For LZMA2 in fast/fastest level:
1 thread provides best сompression ratio.
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Hi,
can someone tell me, in wich cases LZMA2 is better than LZMA?
I´ve compressed some files with both to test the filesize. Some files with LZMA2 are a bit bigger than with LZMA. (most times ISO files)
Thx
Use 2 threads in LZMA2 for better compression ratio.
Compression ratio depends on amount of CPU threads??? Strange...
The compression algorithm isn't exactly the same
there is no black magic: single-threaded algorithm can't be executed without modifications by many threads. and these changes sometimes means less compression, trading speed vs size
If increasing the amount of threads the users expects faster but not different results. This is what I mean.
unfortunately, that's impossible with current algos. for people compressing gigabytes of data loss of comprssion ratio will be not so huge and not so important
Igor P. says:
"Use 2 threads in LZMA2 for better compression ratio."
Better than 1 or better than 3, 4... threads?
For LZMA2 in normal/max/ultra level:
2 threads provides almost the same compression ratio as with 1 threads.
If you set 3 threads, LZMA2 still use 2 threads.
4 and more threads give worse compression ratio.
For LZMA2 in fast/fastest level:
1 thread provides best сompression ratio.