a little confused by speed shift on i7 10750h

[cwell80]

Hi Everyone,

I'm the owner of a new HP Omen 15 (2020 model, with the i7 10750H and RTX 2060). I basically love the laptop as-is. Even with boost set to "aggressive" in the Windows power plan, and with the Omen Center performance control set to "Performance," I don't see sustained CPU temperatures over 85 degrees C very often, if at all. If I disable boost via Windows or even set it to "Efficient Aggressive," then I see even better temps. I can often keep this thing humming along at sub 75 C temperatures while under load (and sub 70 if it's an older game).

BUT, that said, I'm interested in tinkering with Throttle Stop and having further control of boost clock speeds.

So instead of having boost on or off, I'm trying to keep boost somewhere in between the base clock (2.6 GHz) and the max clock (reported as 5 GHz, but HWInfo and Throttlestop show that it's closer to 4.8 GHz). I know I can't undervolt on this CPU without messing with my BIOS and I'm really not willing to do that, so I started looking at the Speed Shift option. I believe that setting it to 0 will force the CPU to favor max clock speed (it doesn't force boost, but it allows for all boost all the time, right?), and setting it to 255 is a lot like turning boost off entirely.

So if I turn it on and leave it at 128, will the laptop behave any differently than if I had Speed Shift off? Because setting it to something low like 28 or 32 seems to imply that the CPU will actually boost more often than it already is.

Said another way: is 128 the default setting for this CPU even without Throttlestop? Or does the CPU operate closer to 0 in most cases?

Thanks for your help with understanding this.

 

[unclewebb]

Different laptop models use different default EPP values. The typical default is 128, mostly because that is half way between 0 and 255. I prefer using 80. On some CPUs, a setting of 128 can limit maximum performance.

To find out what values your laptop uses, do not check the Speed Shift EPP value in ThrottleStop. Open the FIVR window and adjust the Windows power slider from Best Battery to Best Performance. As you move this slider, you should see the Speed Shift EPP value that the CPU is using change. Watch the monitoring table in the top right corner of the FIVR window. I tell people that if Windows can control this appropriately then there is no need to check the Speed Shift EPP box in ThrottleStop. This option was originally added to ThrottleStop for older CPUs or for older versions of Windows that were not enabling or using Speed Shift Technology. Most recent computers running Windows 10 handle Speed Shift automatically.

If a laptop enables Speed Shift in the BIOS, there is no way to turn Speed Shift off after you have booted up into Windows. The only options are to control Speed Shift EPP using ThrottleStop or let Windows control the Speed Shift EPP value. An EPP setting of 255 should be avoided. A slow CPU is an inefficient CPU. The whole point of Speed Shift is so CPUs can quickly burst up to maximum speed, get tasks done as fast as possible and then have the core immediately return to the low power C7 state when it is not needed. The core is disconnected from the internal clock and disconnected from the voltage rail when it is in C7. A CPU core running at 0 MHz and 0 volts is the best way for modern CPUs to save power. Slowing them down to a crawl when a task needs to be performed should be avoided.

 

[cwell80]

To find out what values your laptop uses, do not check the Speed Shift EPP value in ThrottleStop. Open the FIVR window and adjust the Windows power slider from Best Battery to Best Performance. As you move this slider, you should see the Speed Shift EPP value that the CPU is using change. Watch the monitoring table in the top right corner of the FIVR window. I tell people that if Windows can control this appropriately then there is no need to check the Speed Shift EPP box in ThrottleStop. This option was originally added to ThrottleStop for older CPUs or for older versions of Windows that were not enabling or using Speed Shift Technology. Most recent computers running Windows 10 handle Speed Shift automatically.

Oh man, you have no idea how dumb I feel right now. Had I stopped to think about it a little more, I would have tried moving the battery slider.

Instead, I was changing the Processor Performance Boost Mode option in the Advance Power Settings and seeing a constant value of zero. Except for disabling the boost or setting it to "Aggressive" (which basically means "always boost when needed" - this is the default), I still can't figure out what those settings do for users. Is there really any difference between "Efficient Aggressive" and "Aggressive?" If there is, I can't see it. What's funny is that HP's Omen Command Center doesn't seem to impact the Speed Shift either. Whether you're in "Balanced" or "Performance," the CPU appears to be the same. Maybe it's just a matter of fan curves? Or maybe "Performance" boosts the GPU's frequency. I actually see better temps that way.

In any case I did exactly what you suggested just now and Windows does indeed shift the value according to where I position the slider. Half way puts it at a value of 84. I'm going to shift it to around 30 with the slider and see what happens. Then I will test it with Forza Horizon and see if my temps are impacted at all. Like I said, things run pretty steadily on their own but I love tinkering with this sort of thing and it's always fun to see where the right balance of power, temperatures, and fan noise falls.

I really appreciate your quick reply and this tool. Many thanks!!

EDIT: Actually, HP seems to have limited how much you can manipulate that slider. There's only three options: best performance, better performance. and best battery, which gets you speed shift values of 0 or 84. Weird. Maybe I will use ThrottleStop to get somewhere in between. I'll have to play around and see what else "best battery" changes, because it doesn't appear to be processor performance.

 

[unclewebb]

HP seems to have limited how much you can manipulate that slider.

The CPU recognizes 256 different EPP settings but HP and others are realizing that the vast majority of these are pointless. Use 0 for maximum CPU speed and use 84 for a Balanced profile when running on battery power. Sometimes two different settings for the Windows power slider results in the exact same EPP value. It gives a user a warm and fuzzy feeling when they believe they are saving power. The placebo effect.

Slowing a CPU down to a crawl might have been a good idea 20 years ago before the C states were invented. With modern CPUs that can enter the low power C7 state, slowing the CPU down is not that important. Many users only feel good about things when they are running at 800 MHz, right where the CPU is least efficient. Kind of like driving on the freeway at 1 km/h and taking a day to get from one side of the city to the other. That is not an efficient way to drive and 800 MHz is not an efficient speed to compute at.

Then I will test it with Forza Horizon

As soon as there is a load on the CPU, it is going to go up to full speed. You might not see any difference between EPP set to 0 or 84.