BIOS help needed

[nocrapman]

I have a Gigabyte GA-MA790XT-UD4P motherboard with a Phenom X2 550 Callisto cpu for my backup rig. Been running the basic BIOS with a modest OC to 3.3 for power consumption reasons.
Anyway, Today with the mindset of upgrading the cpu to an X6 1055... I updated the BIOS to F8. This went pretty smoothly. Then all these options in the BIOS became available. The EC firmware option on Hybrid basically turned this CPU into an X4 and seems to be running fine.
The CPU is identified as B50 on Coretemp. However there are no temp readings!!

Now I have a question about all these other options:

1. Advanced Clock Calib - on auto for now - leave it there or modify? What is this supposed to do?

2. CPU core control - On auto; change or not; what does this do?
3. As I am still exploring this BIOS, Any other setting that you guys have found to be good for OCing. The system specs are in my sig.

Thanks for the help!!

[jagd]

1-It is used to enable core unlocking mostly ,2nd iirc you can get higher oc when it is enabled (there was an article at anand when acc first introduced ) .
Edit :I thought you had X6 ,keep it enabled to use your x2 550 as X4
2-It is used to control cpu cores .You can disable defected cpu core(s) with this option with unlocked cpu i.e you unlocked dual core cpu and got a quad but one core is not stable than you can disable defected core and can use 3 cores .

[nocrapman]

Thank you! Makes sense.
Now how do I know if a core is defective or which one is defective?
I ran prime 95 briefly with all 4 workers and the computer froze.
But it boots up fine, runs Fritz chess marks ok with a score of 17. I havent done any benchmarking with it yet...

[mastrdrver]

The reason you don't see the core temperature is because the way ACC works it works in the same data area. ACC is a function of the SB and there are a few pins that connect the SB to the cpu directly. The board has a good cpu temperature sensor. Add 3C or so to that and you should be close to core temperature.

If you freeze with P95 then your not stable with all 4 cores. You may need more vcore, cpu-nb, or maybe sb volts only testing will tell. Though if you're only getting 3.3 on stock voltage that doesn't sound like a good chip (if it is a C3 stepping). Try bumping NB (not cpu-nb) up to 1.2v and see if that doesn't help when pushing HTT.

As for the numbers for ACC they have to do with system clocks on the board. As you overclock the cpu when pushing HTT or unlocking cores there are other latencies that might need changing. What exactly they change AMD has kept silent about. Fwiw I've found that changing just one of them off 0 to -2% negatively effected PC Vantage scores but it was only certain ones. If you changed it back to 0 and another to -2% the negative effect would go away. It was very repeatable. It could change the score by 400 points when I ran the full suite.