lucabesa :
is the gigabyte z370p compatible with the i7 9700k after the bios update? I read somewhere that although the update is supposed to support the 9th gen it won't support 8 cores cpus.
If it is actually compatible, can I flash the mobo while using an old cpu to update it(i7 3700k)?
Yeah, it will work.....
BUT, I wouldn't do it because that's a
low end Z370 MB and the VRM's might not be able to handle it for long. Very possible you could burn up the MB due to the weak VRM's.
I recommend staying with the 8700K or if you want to go with the 9th Generation get a new MB.
If you do get another MB don't cheap out on it, get a good one this time.
The 9900K and 9700K pull a lot more power than the 8700K does.
I am running a 9900K on my AORUS Z370 Gaming 5 motherboard and it works great, but that's not a low end MB and it has great power delivery and VRM's.