3. Undervolting (in addition to OC)
I reduced CPU voltage/vcore by 0.25v. And the NB voltage also by 0.25v. Did it inside the BIOS. Everything works stable with
that. I´ve not tried the limits though.
I was confused with the CPUVid values first. Programs like "AOD" and "CoreTemp" always showed me the same CPUVid voltage no
matter how much I reduced the CPU voltage. If I reduced the CPUVid using "AOD" ... after a system shutdown and reboot the
changes have been canceled again.
Then I realized that the CPUVid is not the actual CPU voltage but a maximum value you cannot change. So no need to worry
about that. I later on installed "EasyTunes" to control the CPU fan speed is able to show you the actual CPU voltage and that
fits to what I had set inside the BIOS.
Btw: the CPUVid is at 1.4125v with turbo mode enabled and 3.3375v if it`s disabled.
4. Fan speed control and additional case fans
I wanted to equip my case with two additional case/intake fans. On the GA-990XA-UD3 you have got 4 ports: "Sys fan 1", "Sys
fan 2" (already equiped with an exaust fan), "cpu fan" (already equiped with an cpu fan) and no.4 "power fan".
I`ve tried a lot e.g. using y-adapters on "cpu fan" as well as "Sys fan 2". Nothing has satisfied me. Sometimes the fans
work, sometimes only after a reboot, on the "Sys fan 1" port only with 200 rpm and so on and so on.
First of all: I`ve not managed to change the exaust fan speed connected to the "Sys fan 2" port. It always runs with
half-speed-? (1100rpm).
Via "Speedfan" I`ve managed to set a variable speed to my additional case fans wich in the end I connected to "Sys fan 1".
I´d have liked to use the "Speedfan" program with my CPU fan, too. But it starts to work with too much delay that way.
For the case fans a bit of delay is not so important, though.
Finally I`ve installed "EasyTunes6", there I changed the smart settings for the CPU fan speed a bit. And with that this fan
doesn`t do anything until it gets 27 degrees celsius warm and then starts with half speed and runs on full speed if the CPU
is at 45 degrees. With this setting I don`t get more than 45 degrees when gaming (up to 54 degrees in "Prim95s" blend test
@3.8GHz) and the fan even turns off while doing some office work.
It seems that the MB cannot let the CPU fan work at speeds below 50%. But maybe I`m able to change that via "Speedfan" in the future.
What I´ve read in forums about Gigabyte`s "EasyTunes" you should be very careful using it for overclocking.
Well, as you can see I`ve tried and learned a lot. Sometimes I came near to tears but in the end I`m satisfied with my
system. Hope this may aid other GA-990XA-UD3 users.
Greeting from Germany!
Chris