Extreme Llano A8-3870K LN2 Action: 6GHz Attempt
We used the ASUS F1A75-V Pro from our recent round-up, the reason being it has an 8-Pin CPU power connector, and our other boards only had a single 4-Pin which wasn't enough. This board uses an 8 phase VRM, but just like the others it is lacking Clear CMOS, Reset, and Power buttons as well a POST code display. We cannot even measure voltage from voltage read points, but it is easy enough to find manual read-points around the board if you wanted to, however we chose not to.
First we covered the board with the silicon based conformal coat, to waterproof the board. We even did it to the back of the entire board, and then to the other side of where the DIMMs are. We also did it up to the first PCI-E 16X slot. Special care must be taken to not cover up the MOSFETs, the DIMMs, the Socket, or the PCi-E slots when coating the board. Next we apply heated art eraser to the immediate area around the CPU socket. You want to get it over and into every nook and cranny; it is used to displace air over the electrical components so that condensation cannot form. A thick piece of neoprene was placed under the CPU socket area, and then the POT’s back plate holds the neoprene to the board. We then placed a thermocouple as so that it was touching the CPU IHS. Then we added some Armaflex insulation around where the POT sits to add extra insulation.
Next, place a small amount of thermal paste evenly spread over the CPU IHS. Mount the POT and screw down the hold down, but only use as much force as your hands can provide to screw down the POT. Don't over-do the pressure (by using pliers to tighten hold down even more) or you will crack the CPU when its cold.
Once the POT is wrapped in neoprene and the hold down is secure, we have some fans blowing air up, and not down, as to remove the cold nitrogen vapours which will cause dangerous condensation after a while.
At this point you want to log into the BIOS, and then watch the CPU temperature. Let the CPU warm up to about 60C, it might take a while to get that high, and then pour in LN2 slowly to bring down the temperature. It is important you allow the CPU and POT to warm up, as it allows the thermal paste to cure a bit. You also want to watch the difference between the BIOS CPU temperature and that on your digital thermometer.
Make sure to use a HDD/SSD you are ready to have corrupted, and set SSD/HDD mode to IDE, as AHCI seems to cause data corruption problems when going over 110MHz.
As we're clearly not saving the environment here, you want to turn off EPU and/or TPU power saving options to prevent them from interfering in the overclock.
With max APU multiplier of 47X on an "unlocked CPU" we can use a FSB of 133-135 easily so that we have some room to use 45x, 46x, and 47x to find which one fits the CPU best. So what you want to do first is set the CPU Multiplier a bit lower, we used 43X or even 37X in many cases.
At this point it would be a good idea to set CPU Voltage to offset mode, as the manual mode only allows up to 1.7v, but in windows we can increase the VID to take Vcore over 2v, which is what we need for 6GHz. We found that over 2V has very little impact on CPU OC, but 2V wasn't easy to get working straight from BIOS either. We had to use an AMD program called PSCheck to change the VID and multiplier in windows. FSB was much harder to change outside the BIOS.
We set the maximum offset we could possible select, but make sure that your CPU temperature is below -130C before doing this. We left all other voltages alone.
We maxed out the PWM settings, however we didn't use the maximum LLC setting. Current capability is very important, and so is phase control scheme.
We disable all AMD power saving technologies.
Remember to use IDE instead of AHCI, if you have already installed OS under AHCI, please re-install. You can install windows at -190C and at stock speeds, we did.
Make sure to set CPU temperature monitor to ignore, and set voltage monitoring to ignore as well as the motherboard will be uncomfortable about these extreme values and shows warnings/shutdown.