Update: GIGABYTE has reached out to TweakTown over this story, which we're going to clarify now. GIGABYTE released the iffy BIOS on 25/8, but on 31/8 the company realized there were some problems with the F5 BIOS.
GIGABYTE quickly pulled the F5 BIOS from their website, and on the morning of 9/1 they had the announcements on their forums, with information on the updated BIOS. GIGABYTE is reaching out to affected customers now.
Original story: GIGABYTE X370 motherboard owners, listen up: GIGABYTE has posted a new BIOS for their Ryzen-capable X370 Gaming K7 and X370 Gaming K5 motherboards, with this F5 revision BIOS meant to provide optiomizations to GIGABYTE's boards... but, it did anything but what it promised.
Some users installed the F5 BIOS onto their X370-based GIGABYTE motehrboard, and saw their vCore voltages hit sky high readings of 1.5-1.7V, which is insane as it should sit somewhere around 1.2V or so. With voltages this high, you won't just damage your AMD Ryzen CPU - but you could permanently damage it - killing the CPU.
Users have posted through various forums, warning users that "F5 is dangerous. I did load optimized defaults before and after flashing. Entered settings and started to check memory settings. About 2-3 hours later system was unbootable. I though that board bricked itself, but it seems that it fried the cpu. Local dealer checked the cpu. It's dead, fortunally they agreed to replace it. A lot faster than GIGABYTE. No offical word on forums and ticket is still in new status on esupport".
On another forum, a post added: "That is in the firmware notes but DON'T DOWNLOAD IT!!! That firmware melts CPUs with massive overvolting. Stick with F6 for now". And on another forum, a different post added: "Do not use BIOS revision F5 on your board if you want to keep your CPU. I had temps that were simply too high so I started doing some investigating and the base CPU Vcore appears to be 1.5500v instead of 1.2250v. It still says you are setting 1.2250v but it isn't. If you use Normal and a positive offset it adds that to 1.5500v. If you try to set 1.2250v directly it still provides 1.5500v. It is messed up and who knows what else is messed up too. I tested this on my 1700 (other CPUs may be affected differently)".
Better yet, TechPowerUp forum user 'psyko12' posted something regarding the F5 BIOS fiasco:
Just wanted to share something regarding gigabytes x370 K7 BIOS or maybe other board BIOS that they released on 2017/08/18.
K7 owner here and reporting some findings about the mysterious F5 BIOS that came out on the official site (it didn't go thru the BETA BIOS thread), it was just posted as a "stable" release.
Having flashed the BIOS some users noticed it to set the cpu vcore to a very high voltage 1.55v instead of the default 1.2ish~ v. Having applied optimized settings saved and restarted it went back to normal.
Findings: Most or some users got the same experience.
More info, it is something to do with auto and voltage offsetting that this bug occurs, but if you set it to use a manual voltage and use LLC to compensate then you are golden.
At the moment have read and found out some people getting their processors fried due to this bug. We haven't heard yet from gigabyte in their forums regarding this one.
Minus that very very bad bug, overall the BIOS is very good. It has unlocked more dividers/MHz for the memory (3066, etc.).
+Noticed with the same oc settings that I use, the VRMs are also way cooler than previous set of bioses also my machine idle temps are way lower (atm running sweet spot 3.8ghz on all cores)
+XMP on some kits even on other dies that the godly b-dies can hit XMP with just turning on the setting without further tweaks. (I had to raise RAM voltages to make it stable tho 1.4v)
+The notorious soft brick issue (for me maybe) does not happen (haven't noticed it too on F4). Maybe I just go lucky.
As of date I saw 2 or 3 persons on the gigabyte forum reporting of fried processors.