The new AMD Ryzen 5 7545U and Ryzen 3 7440U chips are the first laptop processors to feature AMD’s new Zen 4c CPU cores, which first debuted earlier this year in some of the company’s EPYC server chips and the entry-level AMD Ryzen Z1 chip for handheld gaming PCs.

So what makes a Zen 4c processor core different from the Zen 4 cores that power most of the chips in the AMD “Phoenix” lineup? In a nutshell, they offer most of the same features, but take up less space and run at lower speeds. But since AMD is bundling Zen 4c and Zen 4 cores together on its new chips, it’s likely that users won’t see a huge drop in performance.

AMD says its Zen 4c cores take up 35% less physical space than Zen 4, which allows the company to either fit more cores into the same amount of space or the same amount of cores into a smaller space.

In the case of these laptop chips, AMD is replacing the Ryzen 5 7540U and Ryzen 3 7440U (yes, it’s the same name) Phoenix chips that launched earlier this year with the new Ryzen 5 7545U and Ryzen 3 7440U “Phoenix 2” processors.

The company is still using the same number of CPU cores (6 for the Ryzen 5 chips and 4 for the Ryzen 3 chips), but now some of those cores are Zen 4c chips, which the company says should bring efficiency improvements, allowing better performance at sub-15 watts and similar performance in the 17 to 20 watt range. You’ll only really notice a significant difference when running at higher power levels, and even then, the difference doesn’t look all that great.

One thing to keep in mind though, is that while AMD officially says the new chips have the same base and boost speeds as their predecessors, that’s a little misleading, because the company is using the numbers for the Zen 4 CPU cores, not the Zen 4c cores. We don’t actually know what the top speeds for those Zen 4c cores are, although Anandtech notes that in server chips, they’re about 30% slower than their Zen 4 counterparts.

But, again, that might not have a huge impact on real-world performance.

Here’s a run-down of the updated Ryzen 7040U lineup, with the new chips highlighted:

Ryzen 7040U Series “Phoenix” for ultrathin laptops (November, 2023)
ModelCPU GenCores / ThreadsBase / Boost CPU freqCacheGraphicsRAMUSB4TDP
Ryzen 7 7840U8 x Zen 48 / 163.3 GHz / 5.1 GHz24MBRadeon 780M
(12 x RDNA 3)
DDR5 / LPDDR5Yes15 – 30W
Ryzen 5 7640U6 x Zen 46 / 123.5 GHz / 4.9 GHz22MB Radeon 760M
(8 x RDNA 3)
DDR5 / LPDDR5Yes15 – 30W
Ryzen 5 7540U6 x Zen 46 / 123.2 GHz / 4.9 GHz22MBRadeon 740M (4 x RDNA 3)DDR5 / LPDDR5Yes15 – 30W
Ryzen 5 7545U2 x Zen 4
4 x Zen 4c
6 / 123.2 GHz / 4.9 GHz22MBRadeon 740M (4 x RDNA 3)DDR5 / LPDDR5Yes15 – 30W
Ryzen 3 7440U (old)4 x Zen 44 / 83 GHz / 4.7 GHz12MBRadeon 740M (4 x RDNA 3)DDR5 / LPDDR5Yes15 – 30W
Ryzen 3 7440U (new)1 x Zen 4 
3 x Zen 4c
4 / 83 GHz / 4.7 GHz12MBRadeon 740M (4 x RDNA 3)DDR5 / LPDDR5Yes15 – 30W

Another thing to keep in mind is that none of the chips featuring Zen 4CPU cores feature AMD’s Ryzen AI technology, which enables some AI-accelerated features like Studio Effects for video apps in Windows 11. But that’s a feature that the Ryzen 5 7540U and older Ryzen 3 7440U processors didn’t have anyway. It’s only available in the higher-performance Ryzen 5 7640U and Ryzen 7 7840U processors.

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  1. The most important thing is that there is still the option of 8 “normal” cores. Then they can add 2 or more ZenXc cores. If you can’t buy a device with 8 “normal” cores, I won’t buy anything from them. Many users will also abandon the purchase. The amount of ZenXc should decrease when talking about X840U and higher models. If I can’t buy “normal” cores, I will choose Apple’s offer (although I don’t like them for the lack of privacy).

    1. I don’t think most users actually know or care about the difference between a zen4c core or a zen4 core, or a thread, or if that particular core supports virtualization. Mostly they’ll notice sluggishness when trying to load a program (which has more to do with storage speeds) and battery life. And in fact until benchmark results start getting publicized it will be hard for anyone to be sure how much of a difference it’ll make. Although given that these still have two threads per core and don’t require a hardware scheduler, I’d be willing to bet that it isn’t worth sacrificing your privacy to appease randos on the internet who you’ll never meet. Once a particular piece of information about you is in someone else’s hands, that’s something they can use against you. And in a world where people are worth so little that everyone is just one bad day from being homeless, you really can’t afford to give them anything unless you want to fully surrender your free will too. Not that we’ll have a choice about that, in the end, the way things are going and can’t be spoken against.

      1. It is necessary to separate: “taking care of privacy” and “providing privacy by agreeing to the terms”. In the first case, I do not share anything and only my or the software’s error determines the loss of privacy. In the second case, I consciously decide to give my privacy to a third party.

        Coming back to the topic of ZenXc. An internet eater does not need devices with 8 “normal” cores. Higher notebook models are bought by people who compile code, edit videos, etc. In this case, ZenXc is worse.

  2. I garauntee you that the likes of lamacpp and koboldcpp are finding ways to take advantage of AI acceleration in their programs.

    I think this particular chip has been so successful because of the Steam Deck and Asus Rog handhelds and others.

    I read in another forum somewhere that AMD was struggling financially. No, they’re not. They made nearly 6 billion last quarter. QUARTER mind you. AMD is strong, and I support them 100%. After more than two decades, they are still my favorite chip company.

    1. Personally, I’m anxiously waiting for DDR6 and 32+ core processors to be mainstream, then I’ll bite.

      Unless RISC-V becomes a decent alternative, then I’ll finally jump the x86 ship for good.

      Either way, AMD is doing well despite some naysayers, and I say good for them!

      1. RiscV is the rising sun. It saddens me that any European entity doesn’t developing this architecture (like ARM from the UK).

    2. Have you read their financial report?
      AMD’s 2Q 2023 GAAP financial report:
      They made $5.4B in REVENUE. Down 18% from 2Q 2022 ($6.6B)
      Net earnings: $27M. Down 94% from 2Q 2022 ($447M)
      2Q 2023 was a bad quarter for them. It’s probably one of the reasons why they’re cutting down their graphics division again and consolidating their GPU lines.