Because the compression is so heavy, your computer has to do a lot of "heavy lifting" to unpack the files.
You need 17 GB of free space for the final game, though you may need up to 34 GB during the actual installation process.
Are you planning to run this on a or a standard Windows PC ?
If you hit a "CRC Mismatch" error during installation, it usually means your antivirus interfered or you don't have enough RAM allocated. Try limited RAM mode (2GB) in the installer if your system is struggling.
How to fix "FAILED: CRC MISMATCH" Fitgirl Repack : r/CrackSupport
Around 40 minutes on an 8-core CPU, or up to 1 hour 20 minutes on a 4-core CPU.