Originally Posted by rv8000
Thanks for the explanations.
Concerning the Scalar, at least by ASUS's definition, the only description they really offer within the bios is that altering the scalar level only allows the vcore/VID to sustain longer durations at it's defined level. They don't really mention anything about frequency, though in turn higher/longer sustained voltage does result in longer periods at a higher frequency. Would one have to increase the VID from auto to +10mV, in theory, to start to see higher frequency jumps even though the Auto OC is set to +200mhz? For instance: if I increased the VID value in the bios/PBO would I see larger than a 25mhz increase when to the best of my knowledge I'm not hitting any of the PBO limits?
Increasing the scalar only helps, if FIT causes a voltage limit that is below the "global Vmax" (LUVL), which is 1.5000V (unless manually set to a lower value, through the control introduced in AGESA 184.108.40.206).
This is rarely the case in ST workloads, but very common in MT scenarios, especially on 3700X and 3800X SKUs. That being said, I've seen it happening in ST scenarios as well.
For example, if you increase the PPT to say 128W, TDC to 100A and EDC to 140A you should see somewhat higher clocks and significantly higher voltages during e.g. Cinebench R20 MT test when you raise PBO scalar from 1x to e.g. 3x.
Thats because in MT scenario the voltage is limited by the stock reliability (FIT) and increasing the scalar (hence reducing the reliability) will allow the use of higher voltages.
Offsetting the voltages won't technically make any difference, since the CPU will follow its AVFS decisions when it operates in non-OC (i.e. manual) mode. Offsetting can get you around the PPT/TDC/EDC limits, but obviously it won't change what the CPU
expects and wants to receive, in terms of the voltage.
Let's say that you have a 3700X CPU with following V/F for Core 1: 4100MHz = 1.3250V, 4200MHz = 1.36250V, 4300MHz = 1.4125V, 4400MHz = 1.4625V.
When you increase the Fmax through Auto OC, the CPU will calculate the V/F for this range as well (most likely through extrapolation, similar to Intel). If it determines that the Core 1 will require
1.4750V for 4425MHz, 1.49375V for 4450MHz and 1.51250V for 4475MHz, then =< 4450MHz is the maximum you will see no matter what you do (due to 1.5000V hard LUVL / Vmax limit). You can offset the effective voltage, but not what the CPU needs and wants to see.
There is room for improvement in the way the AVFS currently behaves however, these improvements will not result in higher peak frequencies (only avg) even if they all would materialize.
There are two ways for the frequencies to improve on 3000-series CPUs: Either the Vmax (LUVL) is allowed to be increased (not going to happen frankly) or the manufacturing process improves from its current state.
AMD has themselves stated in their slides that the Fmax on 3000-series CPUs is being limited by the maximum voltage they can feed to the silicon.