RARLab recientemente ha lanzado una nueva versión de su reconocida utilidad de compresión de archivos: WinRAR, la que llega a su versión 4.2.
El nuevo WinRAR 4.2 trae una larga lista de importantes cambios, entre ellos uno que sus usuarios han estado reclamando durante mucho tiempo: la optimización de sus algoritmos para aprovechar el gran poder de los múltiples núcleos que poseen los actuales microprocesadores, optimización que consigue importantes mejoras de rendimiento para los poseedores de CPUs cuádruple núcleo y configuraciones superiores.
Los nuevos algoritmos usados en la compresión/descompresión de archivos por WinRAR 4.2 no solamente están optimizados para múltiples núcleos, sino también para aprovechar los modernos juegos de instrucciones de los actuales microprocesadores, por los que incluso los usuarios que aún posean equipos con microprocesadores mono-núcleo, aunque los poseedores de viejos procesadores que carezcan de los modernos juegos de instrucciones podrían no beneficiarse de las mejoras al código del programa.
Aquí la lista de cambios completa:
1. Changes in RAR compression:
a) RAR general compression algorithm is optimized for better utilization of several processor cores. While some speed gain is possible even in single processor mode, best results are achieved in multi-core environment.
Speed gain depends on data type and average file size. Several cores are utilized more efficiently when compressing large files.
b) we had to increase memory requirements to achieve higher compression speed. General RAR compression algorithm allocates about 120 MB comparing to 40 MB in WinRAR 4.11;
c) RAR text compression algorithm cannot utilize several CPU cores efficiently, so its performance in multiprocessor environment is much lower than for general algorithm. Also its decompression speed is much lower than in general algorithm regardless of CPU number. So we decided to disable the text algorithm by default.
If you need maximum possible compression ratio for plain text data regardless of speed, you can enable the text compression in «Advanced compression parameter» dialog. Press «Compression…» button on «Advanced» page of archiving dialog to access it. You can also change this option permanently in default compression profile;
In the command line mode the text compression can be enabled with -mct switch;
d) «Fastest» (-m1) compression mode also supports several processor cores now. In 4.11 it could use only a single processor core.
2. RAR general decompression algorithm speed is slightly improved, though not to same extent as RAR compression. RAR decompression is not able to use several processor cores, so its performance does not depend on a number of cores.
3. Changes in ZIP compression:
a) now ZIP compression supports several processor cores resulting in noticeably higher performance in multi-core environment. Single CPU ZIP compression is also faster than in 4.11;
b) memory use for ZIP compression is increased to about 15 MB.
4. Recovery volume creating and processing can use several CPU cores resulting in higher speed. Though, typically hard drive seek speed is a limiting factor for recovery volumes, so this gain is most noticeable when working with solid state drive.
5. Now the allowed value for -mt switch is 1 – 32, not 0 – 16 as before.
6. «Find files» command can search data in 7-Zip archives. Previously «Find files» did not support .7z archive format.
7. Windows 2000 is not supported by WinRAR and WinRAR self-extracting modules anymore.
8. «Save current settings» button in «Advanced SFX options» dialog is now available only when converting an existing archive to SFX. Options saved with this button are applied only to convert to SFX operation.If you create or update SFX archive, only SFX options stored in default compression profile are used. Options saved in «Advanced SFX options» dialog are ignored for these operations.
Los de Planet 3DNow! realizaron una mini-prueba a fin de comprobar las afirmaciones de RARLab, comprimiendo un grupo de ficheros con un tamaño conjunto de 528.115 KB, usando un microprocesador AMD FX-6100, donde el nuevo WinRAR 4.2 casi duplicó el rendimiento de WinRAR 4.11:
- WinRAR 4.11 x64 = 2:02 min
- WinRAR 4.20 x64 = 1:03 min
Fuente: Planet 3DNow!
