# Question about the speed of multi-core HP laptops

• aheight
This machine has a base speed of 2.5 GHz and can run at up to 4.9 GHz with Turbo Boost. This is the same type of CPU as the one in the ZBook, but the HP machine has a dedicated graphics card.Does this mean I don't need to purchase a separate CPU with a base speed of 4 GHz?No. You still need a CPU with a base speed of 4 GHz.No. You still need a CPU with a base speed of 4 GHz.f

#### aheight

TL;DR Summary
Question about speed of multi-core processor
Hi,
I'm thinking about buying a fast laptop with 4 cores but I've never been quite clear just how fast they run. Here's the description of the CPU from HP's website:

ZBook Fury 17 G7 with Intel® Core™ i5-10400H vPro processor (2.6 GHz, up to 4.6 GHz with Turbo Boost, 8 MB cache, 4 core) + Intel® UHD Graphics (9UY33AV)

Does this mean that if I set up parallel processing on all cores, each core "can" run at (or near) 4.6 GHz or the combined sum of speeds of all four can reach near 4.6? If it's the later, what would I need to do to get all four running at the turbo speed (without over-clocking)? Would I need to purchase a CPU with a base speed of 4 GHz for this?

Each core runs at the quoted speed, but "Turbo Boost" happens at light load - unlikely if all 4 cores are running full out.

aheight
Each core runs at the quoted speed, but "Turbo Boost" happens at light load - unlikely if all 4 cores are running full out.

This is an example of my machine:

Processor Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz, 2592 Mhz, 2 Core(s), 4 Logical Processor(s)
running ParallelTable in Mathematica using 2 cores. Note the base speed is 2.5 GHz but my CPU is showing 2.99 GHz which is the 114% frequency shown on the screen on the right.

Does this mean each core is running at 2.99GHz or the total number of cycles that both cores execute in one second is 2.99 billion?

Does this mean each core is running at 2.99GHz
Each core runs at the quoted speed

I'm sorry but I thought I answered this. I'll repeat it, but that usually doesn't help. Each core runs at 2.99 GHz.

aheight
Each core runs at the quoted speed, but "Turbo Boost" happens at light load - unlikely if all 4 cores are running full out.

Turbo Boost happens at light loads? I thought it only happened at peak loads?

No. If many cores are idle, the chip is cool, so you can run the one core working faster.

I see you mean mean light load across cores. What do you mean that turbo boost is unlikely if all cores are running full out though? When I run all cores full out it's still 1ghz above base clock.

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What's shown in #3 is a CPU at 66% load running a hair under 20% faster than base. That's a pretty good boost, but the processor is still only doing 79% of what it would do running 4 cores at the base rate.

TurboBoost is intended to speed up single-threaded workloads on multicore processors. Since speed is limited by heat, one can run one core faster if the others are idle. If all cores are running full out, the chip is likely near the base frequency. Because that's what the base frequency means.

I ended up ordering an HP Z2 G4 Tower Workstation with:

Intel® Xeon® E-2274G Processor (4.0GHz, up to 4.9GHz w/Boost, 8MB cache, 4 core) + Intel® UHD Graphics P630

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