Can someone explain

[Quarttt]

Why does the higher wattage get lower boost clock?

Can someone explain what all these things means and how they relate to actual performance.

 

The image is from asus website for the zephyrus g14

[Electronics Wizardy]

Those are different graphics cards, the clock speed can't be compared.

 

Basically higher end gpus, like the 2060, have more units. More units means more power. So for the sameish power usage, they need to run at a lower clock. But since there are more units, it will be faster

[mariushm]

You're comparing apples to oranges.

 

They're different processors, which have different number of "cores", and the "cores" have different complexity, performance and power consumption.  

 

The frequency isn't everything. 

[Quarttt]

On 10/5/2020 at 11:18 AM, mariushm said:

You're comparing apples to oranges.

 

They're different processors, which have different number of "cores", and the "cores" have different complexity, performance and power consumption.  

 

The frequency isn't everything. 

How to compare graphical power of different laptops then?

I don't know much about comparing Gpu of different laptops without benchmarks

[mariushm]

Find a review of that laptop

Find a review of a laptop with same video card and similar CPU (because a lower performance cpu may hold back the video card even if it's the same model of video card)

 

Look at the fps the reviewer gets in various games.

 

You have to pay attention at a couple of things 

* if the video card model can be configured with two or more power budgets, make sure the model reviewed has the same power budget for the video card as the laptop you're interested in. 

 

For example, - and these are numbers out of my ass, not actual numbers - could have a laptop that has a  RTX 2060 Max-Q card that's limited to using maximum 55 watts, and another laptop with same card but which is not limited (allowing up to 65-70w of power going to video card) - obviously the second laptop will have better performance in graphics IF the processor can keep up. 

 

* processors in laptops also have a power budget and a maximum power they can take and for how long they can use that much power. You can have a CPU that can consume 15w or 25w, and that can be configured by the laptop manufacturer (so it's either always locked at 15w, or you could go in bios to set it at 25w - sometimes they limit it to the lower treshold of 15w or whatever is available for that cpu because the heatsinks are too small to handle 25w processors). 

 

So one laptop could have different performance in some games compared to other laptops even though they have same cpu and video card.  

** cpu is limited to 15w which means is slower, BUT you may run a game that doesn't use the cpu a lot, so the video card can use a lot more power and give you more FPS  OR 

** cpu is limited to 15w which means is slower so a game that uses a lot of cpu will run slow and not use the video card to the best of its abilities because it waits for cpu OR

** cpu is not limited, which means it can go to 25w so it's faster but also produces more heat, which means the video card may have to reduce its frequency/performance so that overall the laptop stays cold enough, therefore in games which don't use cpu a lot, you could get less fps because the video card is warmer because of the cpu. 

 

There's also tricks like "this is a 25w cpu but stays at 15w and can boost to 25w for up to 30 seconds and then the heatsink and fan can't handle it anymore so the cpu has to go back to lower frequencies and 15w power budget"  - you get a high performance in applications that only need it for brief periods of time, but slower performance if an application needs it for long periods of time... games typically are in the second category.

 

So tldr you need to read proper reviews and see what they say about such things. Some fixed numbers don't tell you anything, you just can't make comparisons. 

 

About the apple to oranges bit ...

 

You also have to understand that with each new manufacturing process, chips require less voltage to operate and less power, if the internals are the same. 

So for example, if you take a gpu chip made 2-3 years on 20nm manufacturing process, it may need 1.3v and 60 watts to give 1000 points of performance. 

The same gpu chip could be remade on 12nm manufacturing process, exactly same internals, and would only need 1v and maybe 50 watts of power to give you 990+ points of performance.  

But it usually costs a lot (hundreds of thousands of dollars) to remake a chip to a lower manufacturing process, so it's usually not done, you take a chip and improve on it, add smart things, add more cache memory, add more "cores" 

 

So let's say  20nm chip in my example has 1000 cores, each working together to give you 1000 points of performance at 60 watts.

The 12nm chip could be made to have only 800 cores, but the designers could make each core work more efficiently and smarter, giving you close to 1000 points of performance but with much less power consumption, let's say 50 watts. 

You could also have a model with 1100 cores which needs 65 watts (just 5 watts more) but give you 1200 points of performance (more than 1100 you'd expect if you compare against first chip)

That's why I said you can't compare different generation chips.

 

3 minutes ago, Quarttt said:

How to compare graphical power of different laptops then?

I don't know much about comparing Gpu of different laptops without benchmarks