Because it uses the V2 dat files, it has to decompress them before scanning.
In the dos version there is a switch to decompress the dat file, that you can use after the dat updates (scan /decompress ) If exported into the unix version, then I'd expect it to be --decompress
Note that even after decompressing, I don't believe the performance will be the same as the 5xxx engine. There will still be a performance hit when starting the scanner.
You only need to run
after the dat files are updated. Add it into whatever updating script you use.
And yes, it does make a difference.