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Old 2020-06-18, 15:35   #23
chalsall
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Quote:
Originally Posted by kriesel View Post
Maybe (optional?) compression will help some too...
The files will most likely be effectivly pure noise. No compression possible.
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Old 2020-06-18, 15:55   #24
Uncwilly
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Quote:
Originally Posted by chalsall View Post
No practical amount of compression possible.
Fixed that for you.
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Old 2020-06-18, 15:56   #25
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Quote:
Originally Posted by chalsall View Post
The files will most likely be effectively pure noise. No compression possible.
Agreed If they're like the randomly selected gpuowl save file I just tried in IZArc, the 7z compressed file will be BIGGER than the original.

Last fiddled with by kriesel on 2020-06-18 at 15:56
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Old 2020-06-18, 16:31   #26
chalsall
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Quote:
Originally Posted by kriesel View Post
...the 7z compressed file will be BIGGER than the original.
Information theory 101.
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Old 2020-06-18, 17:22   #27
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Quote:
Originally Posted by chalsall View Post
Information theory 101.
no redundancy = no compression?
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Old 2020-06-18, 18:48   #28
M344587487
 
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Originally Posted by kriesel View Post
no redundancy = no compression?
Sprinkle in some phrases like Shannon entropy and Kolmogorov complexity and you might even get a passing grade. No matter what you do you'll still need to search every time you need to spell Kolmogorov. It's been mathematically proven that no one can retain how to spell Kolmogorov for more than a few days not even the man himself.
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Old 2020-06-18, 19:44   #29
ATH
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Quote:
Originally Posted by kriesel View Post
Agreed If they're like the randomly selected gpuowl save file I just tried in IZArc, the 7z compressed file will be BIGGER than the original.
If you use 7-zip with Compression Level: Ultra, Compression Method "LZMA2" and Dictionary size "24MB" or more, I got a 91M exponent PRP file at 45.647.640 bytes down to 34.239.642 bytes
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Old 2020-06-18, 19:54   #30
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If you use 7-zip with Compression Level: Ultra, Compression Method "LZMA2" and Dictionary size "24MB" or more, I got a 91M exponent PRP file at 45.647.640 bytes down to 34.239.642 bytes
Well done sir! I only quickly tried my default IZArc settings.
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Old 2020-06-18, 20:04   #31
Viliam Furik
 
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Quote:
Originally Posted by M344587487 View Post
No matter what you do you'll still need to search every time you need to spell Kolmogorov. It's been mathematically proven that no one can retain how to spell Kolmogorov for more than a few days not even the man himself.
No, not really. If you are Russian or Slovak, like me, you don't have issues because of the language similarity. Russian and Slovak languages are not as similar, as Slovak and Czech, but have a common basis.
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Old 2020-06-18, 20:07   #32
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Quote:
Originally Posted by ATH View Post
If you use 7-zip with Compression Level: Ultra, Compression Method "LZMA2" and Dictionary size "24MB" or more, I got a 91M exponent PRP file at 45.647.640 bytes down to 34.239.642 bytes
Out of couriosity, I tried to compress P-1 files and LL (etc.) residue files with 7z. The result was always around 100 % compression rate (sometimes below, sometimes above, sometimes having tons of files using "solid" compression). Please teach me! xD Using your settings, I got no better results on the files I tried.
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Old 2020-06-18, 20:15   #33
ewmayer
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Quote:
Originally Posted by ATH View Post
If you use 7-zip with Compression Level: Ultra, Compression Method "LZMA2" and Dictionary size "24MB" or more, I got a 91M exponent PRP file at 45.647.640 bytes down to 34.239.642 bytes
These are Prime95/mprime checkpoint files? Because that's way bigger than needed for that exponent, even with 2 full-length PRP residues - 1 for the PRP tests, 1 for the Gerbicz-check residue - taken into account. A 91M expo yields a residue of ceiling(exponent/8) ~ 11.4Mbytes, a minimal-length checkpoint file will only be of that size plus a few more bytes for metadata. For example, here an Mlucas LL-test checkpoint file for an expo near yours:

-rw-r--r-- 1 ewmayer ewmayer 11196942 May 1 15:45 p89575217

Here a more recent Mlucas PRP residue file, note the doubling in size relative to the exponent due to inclusion of the auxiliary GEC residue:

-rw------- 1 ewmayer staff 25990715 May 3 20:11 p103962577

Here gpuowl - this one is also for a PRP tests but is clearly just of single-residue size, so gpuowl must stash the GEC residue somewhere else ... but the 104960929-old.owl file is the only other one of that size I see. Ah, I get it - gpuowl is storing last-GEC-good residue in the 'old' file, and latest PRP-test residue in the non-old file, and using an on-the-fly method to generate a GEC residue at each restart, rather than a whole-run-cumulative one as I use:

-rw-r--r-- 1 ewmayer ewmayer 13120173 Jun 18 13:01 104960929.owl

Anyhow, try your compression magic on either an Mlucas or gpuowl savefile, you'll see the expected "maximal entropy, effectively no redundancy" result.

Last fiddled with by ewmayer on 2020-06-18 at 20:18
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