Power Stages of a B560M-A

[Joe_Kerr]

Hello everyone,

I have a question for a power delivery problem

Anyone know how to choose power stages (35W, 65W, 125W etc...) on a B560M-A (if that is possible, hope you understand what I mean)

Im looking to use the full 4.4Ghz of my 11400f but at much less power draw than the 150W full load 

[Electronics Wizardy]

Do you have the board now? There should be a option for chaning the turbo limits, thats what I'd do here.

 

But your not lowing power without lowing performance with this setting. It will still let it boost up to 4.4 if power allows, but will lower clocks to hit the power limit.

 

Undervolting can lower power a bit without affecting performance.

[RONOTHAN##]

I think you're a little confused about what power stages are. Power stages are an integrated high and low side MOSFET that convert the 12V DC from the power supply to the ~1.2V DC used by the CPU. These have a power rating in amps that tell how much current they can theoretically handle in ideal situations, though in practice that number more translates to the relative efficiency of the power stage (I.E. a 60A power stage should be significantly more efficient than a 45A power stage, though that does start to break down above ~70A where it comes down to the individual parts for what is actually the most efficient). 

 

It sounds like you're more referring to the power limits than the power stages. Any sort of power limit on that CPU is going to result in it having a lower clock speed under full load, the question is more how much does that extra power actually help performance, and figuring out the sweet spot between extra performance and extra power. This can only really be determined through a guess and check method, so experiment with it until you find the amount of power that is good for your workload without hurting your performance that much. 

 

Also as @Electronics Wizardy said, an undervolt is a good idea to consider as well, since that will lower the power requirements for the same performance level. 

[Tetras]

It is called cTDP in my BIOS and I can choose a lower setting than the CPU's TDP (e.g. 65 watt can have 35 watt), but I'm not sure if the B560M-A supports it. It might help if I knew if your board was Asus or MSI.

 

If it doesn't, you could try changing PL1, PL2 and TAU to achieve the same outcome (11400T is PL1:35, PL2:84).

[Joe_Kerr]

24 minutes ago, Electronics Wizardy said:

Do you have the board now? There should be a option for chaning the turbo limits, thats what I'd do here.

 

But your not lowing power without lowing performance with this setting. It will still let it boost up to 4.4 if power allows, but will lower clocks to hit the power limit.

 

Undervolting can lower power a bit without affecting performance.

Yes, thats the board in my main PC, I sniffed in the bios a lot and 0 options for that, only "Dual Tau Boost"

 

[Joe_Kerr]

15 minutes ago, Tetras said:

It is called cTDP in my BIOS and I can choose a lower setting than the CPU's TDP (e.g. 65 watt can have 35 watt), but I'm not sure if the B560M-A supports it. It might help if I knew if your board was Asus or MSI.

 

If it doesn't, you could try changing PL1, PL2 and TAU to achieve the same outcome (11400T is PL1:35, PL2:84).

The board is a Asus B560M-A

 

[Joe_Kerr]

18 minutes ago, RONOTHAN## said:

I think you're a little confused about what power stages are. Power stages are an integrated high and low side MOSFET that convert the 12V DC from the power supply to the ~1.2V DC used by the CPU. These have a power rating in amps that tell how much current they can theoretically handle in ideal situations, though in practice that number more translates to the relative efficiency of the power stage (I.E. a 60A power stage should be significantly more efficient than a 45A power stage, though that does start to break down above ~70A where it comes down to the individual parts for what is actually the most efficient). 

 

It sounds like you're more referring to the power limits than the power stages. Any sort of power limit on that CPU is going to result in it having a lower clock speed under full load, the question is more how much does that extra power actually help performance, and figuring out the sweet spot between extra performance and extra power. This can only really be determined through a guess and check method, so experiment with it until you find the amount of power that is good for your workload without hurting your performance that much. 

 

Also as @Electronics Wizardy said, an undervolt is a good idea to consider as well, since that will lower the power requirements for the same performance level. 

I wanted to say I want to run my 11400f at turbo boost, but I dont want it to go 150W, I have a Artic I35 which is very good, but I want to limit my cpu to around 100-110W of power

 

[Tetras]

3 minutes ago, Joe_Kerr said:

The board is a Asus B560M-A

There's no mention of cTDP in the BIOS manual, from what I can see.

 

You could try downloading XTU or throttlestop.

 

2 minutes ago, Joe_Kerr said:

I wanted to say I want to run my 11400f at turbo boost, but I dont want it to go 150W, I have a Artic I35 which is very good, but I want to limit my cpu to around 100-110W of power

If PL1/PL2 are configurable in your BIOS, I'd try 65 and 95. If that limits your gaming performance too much, then 95 and 125.

[Electronics Wizardy]

3 minutes ago, Joe_Kerr said:

I wanted to say I want to run my 11400f at turbo boost, but I dont want it to go 150W, I have a Artic I35 which is very good, but I want to limit my cpu to around 100-110W of power

 

Is cooling why you want to limit the power?

 

If so, don't bother, the CPU will thermal throttle if needed. I'd just let the temp be the limit here

[RONOTHAN##]

1 hour ago, Joe_Kerr said:

I wanted to say I want to run my 11400f at turbo boost, but I dont want it to go 150W, I have a Artic I35 which is very good, but I want to limit my cpu to around 100-110W of power

 

You can't have full turbo boost without the CPU going to full power. For reference, the CPU power consumption in a particular workload is a function of the clock speed and voltage, where if one increases, so does the power consumption. The power consumption can vary depending on the workload (Cinebench will pull much less power than Prime95 Small FFTs, for instance), so you could have some workloads where at 4GHz it will pull 100W and another it will pull almost 200W, so just keep that in mind.

 

Because of that, the only way to lower the power consumption without dropping the clock speed is to lower the voltage by undervolting. If you don't want to do that, you have to sacrifice some performance to set a power limit of 110W. In the lighter workloads like games, it will still likely boost to the full 4.4GHz, it's just that in workloads where it can boost to 150+W it will limit the clock speed to prevent it from drawing that much power. 

 

 

Either that or just live with the power consumption. 50W under the occasional full load is not something you'd notice on your electric bill or as heat in your room, and if your CPU cooler is enough to keep it cool at that power consumption, I don't see much reason to worry about it. 

[Joe_Kerr]

21 hours ago, Electronics Wizardy said:

Is cooling why you want to limit the power?

 

If so, don't bother, the CPU will thermal throttle if needed. I'd just let the temp be the limit here

Well cooler can cool 150W easily, just I dont see any reason for a high power consumption

[Electronics Wizardy]

2 hours ago, Joe_Kerr said:

Well cooler can cool 150W easily, just I dont see any reason for a high power consumption

You can lower turbo limits, but its gonna lower clock speeds. Unvolting can lower power with the same performance, but check stability.

 

What is your power consumption now? Its probably well under 150w when gaming. My 12900k uses 240w peak, but gaming its only about 80w.