Optimal CPU Tuning settings for i9 MBP to stop VRM throttling / Explanation of Apple's Engineering F

[leman]

As far as I am aware, the MSR is set to the intel's default ... and clearly Intel expects that if you are going to use this default, you will have a machine capable of delivering 100 Watts of power steady state.

Btw, I was looking at it and I don't think this is Intel's default. Intel docs say that the default is CPU's TDP. Rather, what I think is happening is that Apple has chosen an arbitrary large TDP numbers to remove all restrictions from the CPU, so that the thermals are the only limit. And since no CPU so far was actually able to pull that much power, this has worked well for them and gave them decent CPU performance.

However, they most likely "missed" the fact that Coffee Lake (and i9, particularly), can draw 100W or even more, which is well beyond what the power system can supply. If my guess is right, this is just sloppiness. Not the first time it would happen... Fortunately, its not difficult to fix. They can set the limits to what the VRM can handle (Apple probably knows it better), which should fix power throttling and make the performance more consistent. I sincerely hope for a quick patch.

 

[dof250]

The Volta tool is now updated to support higher wattages up to 90W on my 15" 2.2 i7 base model.

 

[abn5x]

I'm just mesmerized how I posted this program earlier and got bashed by some users and now its all fine and tinkly ‍♂️

 

[maflynn]

Tbh, I think this is great news but are those specific settings for the i7 2.2GHz? I've I have to plug in a string of hex numbers, I want to have full grasp of what its doing and I don't. I'm not knocking the OP, he did a great job, and I'm not down on the solution but I'm hesitant to alter a setting on the CPU with a string of numbers that may be meant for a different CPU on mine.

 

[leman]

Tbh, I think this is great news but are those specific settings for the i7 2.2GHz? I've I have to plug in a string of hex numbers, I want to have full grasp of what its doing and I don't. I'm not knocking the OP, he did a great job, and I'm not down on the solution but I'm hesitant to alter a setting on the CPU with a string of numbers that may be meant for a different CPU on mine.

No, it’s not CPU specific. It just sets general limits. It’s the same, really, as what the Volta tool does. Of course, there might be more optimal values for your particular machine, but I would t tweak all this stuff too much without knowing what you do exactly

 

[maflynn]

but I would t tweak all this stuff too much without knowing what you do exactly

Exactly, while Volta may not give me the optimum setting, I have it altered to a high degree that the laptop runs relatively cool and I'm happy with the performance. I'm in no way taking anything away from the hard work the OP did and for him he found a great solution that provides a very granular solution to adjusting the CPU to avoid throttling. For me I'm happy with what I have in place

 

[Nozuka]

I'm just mesmerized how I posted this program earlier and got bashed by some users and now its all fine and tinkly ‍♂️

Don't take it personally. People just thought it seemed suspicious, because it was your first post

 

[shavou]

For me I'm happy with what I have in place

Does it mean will you keep it? In other words, would you buy it again if you had the chance?

 

[maflynn]

Does it mean will you keep it? In other words, would you buy it again if you had the chance?

Short answer, I'm definitely keeping it.
Long answer, I had bought another laptop that I returned, partly to see if apple releases a new laptop. That was fine in many respects, but it revealed to me what I'm missing with the apple experience. I raise that now, because if I return the MBP, what will I get? Dell? They're dealing with similar throttling issues. Razer (That's the one I bought), its a good laptop, but it runs hot as well. Any Coffee Lake CPU has varying levels of temperature issues. The benefits of the MBP outweigh the negatives and while the throttling could have been a show stopper, I have a workaround that provides a good balance of performance at decent temps

 

[drvelocity]

FWIW I tried op's settings on my i9 and ended up with much worse scores in the mid 800's, where Volta gives me upper 900's with a 49W limit and a 100mV undervolt (turbo boost enabled). I'd probably need to do more tweaking with the various values to hone in on my particular chip's abilities.

Thanks OP for the fantastic info and sharing your extensive knowledge with the forums.

 

[The Mercurian]

Short answer, I'm definitely keeping it.
Long answer, I had bought another laptop that I returned, partly to see if apple releases a new laptop. That was fine in many respects, but it revealed to me what I'm missing with the apple experience. I raise that now, because if I return the MBP, what will I get? Dell? They're dealing with similar throttling issues. Razer (That's the one I bought), its a good laptop, but it runs hot as well. Any Coffee Lake CPU has varying levels of temperature issues. The benefits of the MBP outweigh the negatives and while the throttling could have been a show stopper, I have a workaround that provides a good balance of performance at decent temps

If you bought a Dell for example you would also be saving a fair amount of cash. If Dell sold their 15" with Ubuntu factory installed I would buy that. But they only sell the 13" with that option and I don't want to spend time hacking a 15" to make ubuntu work. And the 13" would not give me 32GB RAM or hex core - both of which I want. So Win10 puts me off the 15". Which leaves me without a decision and this topic sucking up ever more of my time

 

[M.Rizk]

FWIW I tried op's settings on my i9 and ended up with much worse scores in the mid 800's, where Volta gives me upper 900's with a 49W limit and a 100mV undervolt (turbo boost enabled).

Thanks OP for the fantastic info and sharing your extensive knowledge with the forums.

Seems like the i9 will require different values.

Regarding Volta. It doesn’t support undervolting so just disable this. Just keep the power limit. Also have you tried higher values for power limit? If yes, did you get lower scores so you returned to 49?

 

[Mr Screech]

OP's solution stresses the VRM's a lot less than other software options, correct?
So for laptop-lifetime I'd go for OP's option until Apple makes an official fix.

 

[M.Rizk]

OP's solution stresses the VRM's a lot less than other software options, correct?
So for laptop-lifetime I'd go for OP's option until Apple makes an official fix.

Voltage Shift stresses the VRM more than Volta does because Voltage Shift allows in this case the CPU to take full advantage of the turbo boost for the first few seconds.

Both software stress the VRM much less than Apple default settings do.

 

[abn5x]

op, did you try undervolting with VoltageShift ?

 

[drvelocity]

op, did you try undervolting with VoltageShift ?

I just tried undervolting with VoltageShift and unfortunately it has no effect (results are 0mv undervolt for both CPU and GPU).

 

[abn5x]

View attachment 772301

I just tried undervoltiing with VoltageShift and unfortunately it has no effect (results are 0mv undervolt for both CPU and GPU).

oh **** mind if i ask do you know which adress means what in the MSR? maybe there is an adress for unlocking the VIDs or is this hardware locked ?

 

[risottto]

Not sure you’d want to do that now. I wish Apple put the VRMs on the heat pipe path, but this at least gets us much closer to the performance seen by this chip in other machines.

You can pop off the base cover and stick a thermal pad on the VRM to conduct heat to the aluminum shell, i believe Dave Lee recommends this for the XPS 15. Totally reversible if you ever bring it in for repair.

 

[dburkland]

I ended up building a launchd plist file for this, here are the steps to get it installed:

• Download & install VoltageShift under "/opt/VoltageShift" using the instructions previously posted
• Create the "/opt/VoltageShift/voltageshift_exec.sh" file and copy the contents below into it:

• #!/bin/bash
  cd /opt/VoltageShift
  ./voltageshift write 0x610 0x4283E8001B8188
  ./voltageshift read 0x610

  
  
• Create the "/Library/LaunchDaemons/com.dburkland.VoltageShift.plist" file and copy the contents below into it:
  

  <?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
      <dict>
          <key>Label</key>
              <string>com.dburkland.VoltageShift.plist</string>
          <key>ProgramArguments</key>
              <array>
                <string>/opt/VoltageShift/voltageshift_exec.sh</string>
              </array>
          <key>RunAtLoad</key>
              <true/>
          <key>StandardOutPath</key>
              <string>/opt/VoltageShift/voltageshift_exec.log</string>
          <key>StandardErrorPath</key>
              <string>/opt/VoltageShift/voltageshift_exec.log</string>
      </dict>
  </plist>

• Configure the plist file to start at boot

• launchctl load -w /Library/LaunchDaemons/com.dburkland.VoltageShift.plist

 

[MrGimper]

OT I know, but does anyone know if these tools can be used on, say a 2014 13", to reduce voltages from defaults and potentially reduce heat and increase battery life?

 

[crinkleshoes]

You can pop off the base cover and stick a thermal pad on the VRM to conduct heat to the aluminum shell, i believe Dave Lee recommends this for the XPS 15. Totally reversible if you ever bring it in for repair.

Any idea on the thickness required please?

I'm planning to re-do the thermal paste and would be nice to do this at the same time so that I only have to remove the base once.

Thanks

 

[risottto]

Any idea on the thickness required please?

I'm planning to re-do the thermal paste and would be nice to do this at the same time so that I only have to remove the base once.

Thanks

Re-paste on the 2016-18 requires popping the motherboard off to get to the screws on the bottom (keyboard side) ... a bit more involved than 2012-2015 where it just comes off.

My MO would be to have some 1.0mm and 0.5mm pads handy. I would put a small ball of kneadable eraser on the chip, press the cover on without screwing it in, the pop it back off and see how much is squished down and put in thermal pads to match that thickness.

 

[crinkleshoes]

Re-paste on the 2016-18 requires popping the motherboard off to get to the screws on the bottom (keyboard side) ... a bit more involved than 2012-2015 where it just comes off.

My MO would be to have some 1.0mm and 0.5mm pads handy. I would put a small ball of kneadable eraser on the chip, press the cover on without screwing it in, the pop it back off and see how much is squished down and put in thermal pads to match that thickness.

Yeah, I'm not too worried about the dis-assembly... I've taken apart various laptops for repair so that doesn't phase me... just would like to do it once rather than twice. I might wait a little bit until someone else has done it as it's best for heat transfer to use a single pad than layer pads together.

I dunno... I might be the one to do it.

 

[MacRS4]

I've been testing this on my i9/512Gb/32Gb unit, mainly with some video encoding. I've used exactly what was outlined in the original post, and the times I'm seeing averaged on three runs are as follows:

Surface Book 2 - just for the lols: 23 minutes 11 seconds
2017 macbook Pro i7 2.9Ghz: 12 minutes 44
2018 macbook Pro i9 2.9Ghz: 11 minutes 22, and then 10 minutes 27 after these changes

Anyways, thought you may be vaguely interested.

 

[kotlos]

@winterny You are awesome!

I implemented the solution that you had, but I am getting significantly worse performance.

On average I get much higher temperatures than you.

When PL1 time is 8 I can see the throttling kick in before it sets to PL2 which results in a score of 990 for the first run. When setting the PL1 time to 7, it improves to ~1050 but still temperatures quickly rise to >95C and the frequency in PL2 with the 49W limit is ~3.1. Also that does not give me consistent results, since when I run it with the same settings (7sec PL1) it can still throttle and go into this oscillatory pattern. All this is with the fans maxed out and an ambient temp of 82F.

I wonder if the problem is the ambient temperature, or the variability across i9/VRM chips.

Any ideas?

My next step would be to add thermal pads on the VRM and heat pipes to get some of the heat dissipate through the base.

Thanks again for all the effort!

By the way, when I run the updated Volta app with a 55W limit I get a similar score of ~1050.