Intel Core i7-8550U vs Core i7-7700HQ – the performance is Watt matters!

A few days back we got a hold of a final unit of the new Intel Core i7-8550U that over-exceeded the expectations we had from the pre-production unit. It rocked in every benchmark despite the low TDP of just 15W.

The Core i5-8250U that we have also tested turned out to be just as powerful as its high-performance (HQ) counterpart from the 7th generation – the Core i5-7300HQ. This outcome really boosted our expectations and it is only fair to compare the Core i7-8550U the same way.

We are going to see how the 8th gen ULV Core i7 stacks next to the 7th gen HQ Core i7 used in most gaming notebooks.

Check out all available notebooks with these CPUs in our Specs System: Core i7-8550U / Core i7-7700HQ

Specs overview

While the two chips have a lot in common due to the fact that they are both based on the same 14nm Kaby Lake architecture (though the Core i7-8550U is based on the new refreshed version), they also sport a few very distinctive differences.

One of the features they share is the number of cores and threads. The big update with the Kaby Lake Refresh chips that even the ULV chips now feature four physical cores and Hyper-Threading (eight threads) is a fact we never get tired of repeating. The Core i7-8550U features the same core/thread configuration as the high-performance Core i7-7700HQ.

This fact is not so special on its own but it becomes quite fascinating when you add up the TDPs of both chips to the equation. The Core i7-7700HQ needs 45W to power its four cores and eight threads while the ULV Core i7-8550U accomplishes the same with just 15W or, to paraphrase that, it uses three times less power.

Of course, there isn’t any magic going around here and there is a reason for the extremely low TDP of the Core i7-8550U. To accommodate all eight threads and keep the power consumption low, Intel had to cut corners but the company did it in a brilliant way. The Core i7-8550U (and every Kaby Lake Refresh chip so far) has a very wide range of frequencies. The base clock of the ULV chip starts from just 1.80GHz opposed to 2.80GHz on the Core i7-7700HQ. However, the Core i7-8550U’s boost clocks exceed those of its rival by 200MHz (4.00GHz vs 3.80GHz). This results in a huge amplitude of 2.20GHz. Of course, the TDP goes up to 25W when loaded but it doesn’t go near the 45W of the Core i7-7700HQ.

The Core i7-8550U can also underclock to as low as 800MHz in favor of just 10W of power consumed. We should note that the Core i7-7700HQ also has a specific configurable TDP-down of 35W which is again more than the maximum of the Core i7-8550U.

Interesting to say, the Core i7-8550U has more cache than its rival – 8MB vs 6MB. On the other hand, the Core i7-7700HQ features a better graphics processor – the HD Graphics 630 opposed to the UHD Graphics 620 which is essentially a rebranded HD Graphics 620.

Benchmarks

As you can see in the graph below, the two chips are very close to one another. If one of them scored better in one benchmark, then the other will beat it in the other test. The difference is usually below 10% which is negligible on most occasions.

It is very interesting that the ULV Core i7-8550U managed to perform our preset of actions in Photoshop one second faster than the Core i7-7700HQ. It seems that even though the base clock speed of the ULV chip is low, it can pump enough horsepower when needed.

Results are from the Cinebench 20 CPU test (the higher the score, the better)

Results are from our Photoshop benchmark test (the lower the score, the better)

Results are from the Fritz chess benchmark (the higher the score, the better)


Conclusion

To be fair, we expected the Core i7-8550U to be a bit less powerful than the high-performance Core i7-7700HQ but we might have been wrong. By the looks of it, the Core i7-8550U seems to be a worthy opponent to the Core i7-7700HQ. We can’t be sure of its dominance but we can’t say it falls short. When we get more notebooks with different manufacturer settings and cooling systems, we will be able to get a better wider view on the performance of the new Core i7-8550U.

For now, we can give kudos to Intel for creating such a powerful high-performing chip while maintaining a low power consumption which is the best thing that could happen to a laptop.

We would recommend sticking to the Core i7-7700HQ because of the overall better performance at a lower price (based on Intel’s website) but the Core i7-8550U is the clear winner in terms of performance per watt ratio.

All laptops with Intel Core i7-7700HQ


All laptops with Intel Core i7-8550U

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Momelosegno
Momelosegno
6 years ago

Thanks miroslav, amazing comparison.
This i7 8550u is really a bomb. Now I expect a review of a notebook with i7 8550u to confirm these outstanding results.

Amlan
Amlan
6 years ago

“The Core i7-7700HQ needs 45W to power its four cores and eight threads while the ULV Core i7-8550U accomplishes the same with just 15W or”

This is not entirely correct. While TDP has some correlation with the amount of power drawn to run the processor, the TDP is a measure of the amount of heat dissipated from the processor, and not power drawn.

Here is the reference from Intel – https://www.intel.com/content/dam/doc/white-paper/resources-xeon-measuring-processor-power-paper.pdf

ahmedp800
6 years ago

This is just amazing!