i installed a bunch of time many linux distro and never got this "bug". It's kind of weird, the system run really fine , but when there is operation like update manager or download via any browser , etc. It goes well until a moment (never the same delay) and radically slow down or even stop , the pc doesn't freeze but the operation is paused , and when i touch the touchpad it continue .
i suspected hard drive issue , so i changed it , a bios issue , except AHCI i can't modify anything..., also suspected that ACPI stop the drive so i unchecked the box but still the same bug.
if anyone has already got this... it's not a deadly bug but a big annoyance.