OK, this is my first and last time buying Gigabyte
I got GA-MA790X-UD4 v1.0 MB, and since then I had numerous problems with it.
1) On BIOS F1,F2 ACC is not working at all.
2) ON BIOS F3,F4,F5, PC couldn't boot if Virtualization is enabled. Cold boot is not possible when ACC is enabled (need to press reset button to boot). When booted with ACC system BSOD when I run Prime 95 (on stock CPU clock)
3) Default CPU voltages are too high on BIOS F2A and onwards. Gigabyte support team said that it is done to improve OC. (shocked) How LAME! If someone wants to OC will increase vcore from the bios!!! There is no need to be rised by default!
4)There is no propper CPU fan PWM control (my biggest problem). I have to have installed windows to get my CPU fan controlled by ET6. What if I run linux ? All oher brands MBs I had had a PWM controll in BIOS to keep CPU fan at low RPM and they had an option to set exact RPM you want when CPU is under certain temp. On gigabyte there is no such option and my CPU fan spins at 2300 RPM wich is unecessery loud. I have to boot in Windows to spin it down to 1400 RPM. And this is not the worst part: When gaming, my CPU fan spins up to 2800 RPM for 10 sec. and then back to normal with no reason, CPU temp did not exceed 50C. It happens randomly! I have contacted support team and they said that they working on the problem since F2 BIOS, now F5 is out and it still did not solve this issue.
5) CPU temps rise by ~10C with BIOS F2a onwards. (what the hell). My CPU idleing at 40C (stock clock, undervolted to 1.2V) !!!! Reaches low 60C in 1 min. on prime. On F2a BIOS it hardly reaches 45C
6) onboard sound card is RUBBISH. Sound is very low quality, crackling all the time when ET6 is loaded. I have to close ET6 to get better sound quality BUT then my CPU fans is irritating me! Again gigabyte team said that they know about this issue and working on it since F2a BIOS - still nothing!! I bought external sound card for £10 and it outputs way better sound than onboard one! partially solved this issue, but the problem with the fan that spins up and down drives me mad.
This is the worst MB I ever had.