3.4 GB often acts as a ceiling or a specific usage point for various applications:
4 GB text file, or are you trying to on a device showing this usage? (3.4 GB)
Historically, 32-bit systems were limited to addressing roughly 4 GB of RAM, but "hardware reserved" memory often left users with only about 3.4 GB to 3.5 GB of usable RAM [13]. (3.4 GB)