i7 6700HQ won't clock above 1.7GHz...

Hi all, I've noticed as of recent the i7 in my 6700HQ won't clock above 1.7GHz. I have tried both Prime 95 and Cinebench R15. Does anyone know what settings could be causing this? I originally thought it was my undervolt settings, but same problem with default voltages...

 

What notebook do you have?

 

9550...

 

You're likely suffering from the VRM problem

Here to fix:

 

Check Dell power manager. If the fan profile is set to ultra quiet or whatever it is, it won't let the CPU turbo.

 

You can also install free ThrottleStop software. Then click SpeedShift (set EPP between say 0 and 78) and that should allow your CPU to run full turbo speeds. Don't run this & Intel XTU at the same time as they tend to conflict.

As Danish notes, if your CPU runs full turbo but then drops speeds on benchmarks, you may have a throttling problem.

 

If the Dell fan control is set to ultra quiet it will override TS settings though.

 

Not the case on my 9550. SpeedShift will override and allow the CPU to hit max turbo clocks on my Skylake i5 (6300HQ) regardless of setting on Dell Command I Power Manager.

Of course EPP needs to be set rather low (say between 0 and 80) for max turbo.

 

Have you tried it? In the long long ago when I had my 9550s it wouldn't. The first time I ran across the cpu not clocking up I was stumped till I remembered that I had set ultra quiet mode. Maybe Dell fixed that.

 

Tried it just before I wrote the previous post.

In my experience you are correct as a general matter. But if one enables SpeedShift, SpeedShift takes priority and does allow the CPU to hit max clocks on my 9550.

 

Glad it works now. I did have speedshift on with TS when I had the issue. Even setting EPP to 0 wouldn't allow the CPU to clock up. I think I noticed it when trying to run a benchmark or something like that and I was quite perplexed.

 

In principle, SpeedShift should move more CPU control from Windoze to the CPU. Not quite sure how hidden BIOS errors can screw things up but I suspect that was the issue.

The XPS BIOS was a mess at release of the 9550 & 9560. The latest BIOS still do not support SpeedShift (the Skylake and Kaby Lake CPUs certainly do as ThrottleStop never had a problem enabling SpeedShift).

Dell has sorted out a lot of the BIOS problems so I suspect some of the fixes (inadvertently) solved that SpeedShift glitch.

 

Thanks for the replies.

The system has been repasted and padded, so thermal throttling is not an issue.

I will check Dell Command when I get home - should it be set to Ultra Performance?

I already have TS installed which I use for undervolting, but I’ve never touched SpeedShift. What would be the most ideal SpeedShift setting to use?

Thanks

 

In ThrottleStop:

- Check the box Next to SpeedShift (SST letters will turn green)

- Set EPP between 0 (for max performance) and 255 (for min energy use)

- EPP 128 is mid range per Intel but that probably prevents max turbo speeds. If you want max turbo access, EPP probably needs to be below 70 (you need to check on your system).

More details at:

http://forum.notebookreview.com/threads/dell-xps-speed-shift.796891/

You can also use Dell Command I Power Manger. That gives you access to some power and fan settings that you may not be able to access elsewhere. Click Quiet, Optimized, Cool, Ultra Performance depending on your task (e.g. use Ultra Performance with a low EPP)

 

Good news! Changing from Quiet to Ultra Performance in Dell Command puts the clocks speeds back up to normal even with SST disabled. Is having SST disabled the same as having it enabled and on "1"?

 

No.

 

Would it be better to use SST or is it fine to keep off? I think I might actually put Dell Command back to Quiet as this system is mainly only used for browsing, and battery life is my main priority. I was just curious as to what was originally causing the low clock speeds

 

In older CPUs, people tried to reduce clock speeds to save energy. With modern CPUs, you generally want the CPU to execute tasks very rapidly, thus allowing cores to rapidly enter deep sleep states where they enjoy virtually zero power consumption. SpeedStep and SpeedShift were introduced to facilitate this; SpeedShift is next gen technology so significantly more efficient AND higher performing. The ThrottleStop Guide thread has much more detail.

Default, your 6700HQ will run the old SpeedStep because Dell didn't bother to finalise the BIOS. With ThrottleStop you can run SpeedShift and find an optimal EPP (you might find 255 laggy but select highest figure that is not irritating).

With respect to Dell Command, I don't know what those adjustments do but quiet might use less power based on the fan and processor description. You will need to do some trial and error.

 

Okay, I've been playing around a bit with SST and EPP. Just wondering, is it more efficient and better on battery to set Max Multiplier say 18, and leave EPP on 70, or, Max Multiplier 35 and EPP on 128?

 

As I noted above, changing multiplier was for older CPUs. You should not be using those buttons on newer CPUs like your Skylake. Adjust with EPP.

 

What about executing longer tasks rather than short tasks, say watching a 4K YouTube video in full screen for example...

With EPP at 128 & Multiplier 35: CPU sits at 2.8GHz, 0.9V, 12W draw & 42C degrees - video is laggy and audio is crackling

With EPP at 70 & Multiplier 18: CPU sits at 1.8GHz, 0.75V, 9W draw & 38C degrees - completely smooth playback

 

Whatever works for you. . .

 

I still don't get changing multipliers in TS when you have speed step, it's one or the other.

I find it hard to believe that 1.8ghz plays videos better than 2.8ghz.

 

I didn't understand it either, but 1.8GHz with a lower EPP plays video MUCH smoother, cooler and uses MUCH less voltage than 2.8GHz with a higher EPP - you should test it for yourself. I'm assuming that upping the EPP changes many other things than just the multiplier, as it seems to throttle performance significantly, even if running at higher clock speeds.

Btw, I have SpeedStep disabled - Only SpeedShift is enabled, EPP at 70 & Max multiplier set to 18. Runs extremely efficiently and is still very snappy to use