How long it will last? I must live a charmed life. I still have (2) Windows XP computers and a Vista running. The only ones I ever threw in the trash were still running, but W3.x and W95 just aren't good enough for today's world. They had to be put out of their misery

 

If it helps, here are the manuals for each one.

Both boards are fairly up-to-date, so I expect if they continue to work for the next 5 years, they won't become obsolete in that amount of time. You never know though

Gigabyte: http://download1.gigabyte.ru/manual/motherboard_manual_ga-ex58-ud3r_e.pdf

Asus: http://www.datasheets.pl/motherboards/MOTHERBOARD_ASUS_SABERTOOTH-X58.pdf

 

I used to repair and build PC's daily and used both brand motherboards for years.
50 Gigabyte MB's about 20% had to be replaced within 1 year, another 20% the next year. Asus we installed 75 boards, after 3 years when I left 72 boards were still running from initial install.