Intel(R) Core(TM) i7 8750H turbo speed

[alfani]

Hello,

I have just bought a new laptop with this processor and on its specs it is mentioned that turbo speed goes up to 4.10 GHz.
I have done a rendering job on it and by checking the speed on my task manager, I found out that although the CPU was used at 100% the processor speed was only 2.80 GHz.
I have contacted the laptop company and they asked me to check on BIOS if the turbo option was enabled, but it was already enabled by default.
Some other thoughts are that the power supply is not powerful enough to support the turbo speeds or some power saving settings on Windows could limit the speed?
I have also read somewhere that the maximum turbo speed is only meant when the processor is using just a single core. Bu if this is true, what should be the turbo speed if all cores are used? Is 2.80 GHz not too low? And do we have any option to control how many cores will the processor use?

 

[bwang]

Its probably power limiting - XTU will tell you why your processor has dropped out of Turbo.

 

[tangoseal]

Turbo is not all cores. Turbo doesnt work that way.

Under an all core load the chip will run at non turbo clocks to maintain tdp.

The laptop chips are not as fast as desktop chips in clock speed because yes .. power supply sizes.. power savings. Thermal solution being smaller...tdp etc..

It's normal. They are not workstation chips with huge cooling water blocks etc.. there is nothing the manufacturer of your laptop can do to change Intels design parameters.

The base speed of that chip is 2.20ghz so I'd say 2.8 full load is quite a substantial turbo for a laptop.

Here is the ARK for your reference.

https://www.intel.com/content/www/us/en/products/processors/core/i7-processors/i7-8750h.html

 

[CAD4466HK]

From TechSpot:

The key improvement to the i7-8750H is in its core count: we’re now looking at 6 cores and 12 threads, up from 4 cores and 8 threads in the i7-7700HQ while keeping to the same 45W TDP. To fit these extra cores under the same power envelope, Intel has gone with the same approach they used with 'Kaby Lake Refresh' U-series CPUs: the base clock speed has been reduced from 2.8 GHz in the 7700HQ, to just 2.2 GHz with the 8750H.

While the base clock has been reduced, Intel is pushing single-core performance higher with these new 8th gen processors. The 8750H hits a maximum of 4.1 GHz on a single core, up from 3.8 GHz on the 7700HQ. It’s also capable of this same 4.1 GHz clock speed on two cores, along with 4.0 GHz on up to four cores, and 3.9 GHz on up to six cores. That’s a pretty big jump in clock speed considering the 7700HQ topped out at 3.4 GHz in all core workloads.

 

[Azrak]

What laptop?
My Gigabyte Aero 15xv8 (same cpu) will throttle under high load due to thermals. It's a thin design with a somewhat anemic cooler, so it's expected.
You could try undervolting to reduce thermals and possibly gain speed but you need to verify stability and every CPU is different.
Look up Throttlestop and Intel XTU.
Also download HWiNFO and use it to monitor temperatures/voltages and to see which limit the CPU is hitting (power/thermal). It's a great utility. https://www.hwinfo.com/

 

[unclewebb]

I have also read somewhere that the maximum turbo speed is only meant when the processor is using just a single core.

The 8750H adjusts its maximum speed based on how many cores are active.

1 or 2 Cores Active - 4.10 GHz
3 or 4 Cores Active - 4.00 GHz
5 or 6 Cores Active - 3.90 GHz

These speeds will only be reached if the CPU is not thermal throttling or throttling because it has reached one of the turbo power or current limits.

I'd say 2.8 full load is quite a substantial turbo for a laptop.

When properly setup, a fully loaded 8750H can run all 6 cores at a steady 3.90 GHz without a hint of throttling. Cinebench scores of 1300+ are possible but it depends on the laptop. Many so called gaming laptops are poorly designed with inadequate cooling and restrictive power limits that are locked down in the bios by the manufacturer.

The WalMart Overpowered series uses the TONGFANG chasis. Its 8750H benchmark scores are the envy of the competition. Here are some screenshots that show how to get the most out of an 8750H while using ThrottleStop.

http://forum.notebookreview.com/thr...gk5cq7z-gk5cp0z.815943/page-379#post-10869138

the processor speed was only 2.80 GHz

If you take the time to learn about these processors, there is lots of room for improvement.