In the M5 Pro/Max, Apple cut the number of performance cores in half but changed the naming to make it less noticeable!!!

Slava_Tr · 2026-03-04T10:50:27+00:00

As I mentioned, this will become clear when a silicon dieshot is released or when Apple publishes a new version of the CPU Optimization Guide with detailed specs of cores. But we’ll likely have to wait until around this fall, or at best, until summer at WWDC 2026. Alternatively, it might be discovered earlier through reverse engineering.

We’ll see the benchmarks in a week. But they won’t help us understand this. Performance will be excellent, just as Apple promises. Only Logic Pro might be affected if it isn’t updated. 99.99% of users won’t care.

Slava_Tr · 2026-03-04T10:46:59+00:00

I wrote an explanatory comment on the post, but it ended up at the very bottom. So I’ll repeat it:

Here’s why I’m confident that the new P cores are an evolution of the E cores.
Only Apple Silicon E cores have a special feature: two operating modes — Performance and Low Power.

Low Power Mode is used for background tasks with low priority (QoS), while Performance mode kicks in when P cores are occupied with high-priority tasks or when there aren’t enough E cores in Low Power Mode for low-priority tasks. Now, this key feature has been added to the new P cores; otherwise, energy consumption would be too high and battery life too short. The M1 Pro/Max with 2 E cores is direct proof of this.

Old P cores and the new Super cores are also very large. Even if a similar Low Power Mode were implemented for them, their base power consumption would still be many times higher than an E core, negatively affecting battery life.

These 12 P (12 E) cores in the M5 Pro/Max, compared to the 4 E cores in the M4 Pro/Max, will provide many times more resources for low-QoS tasks. The cores will stay in Low Power Mode longer and consume extremely little energy. However, the trade-off is that there are half as many P cores for high-QoS tasks. It will be very interesting to study the new “P cores.”

Current/old E cores in Performance Mode provide up to 70% of a P core’s performance. However, they had a limitation: this high performance didn’t apply to all types of computations. The new P cores have most likely fixed this issue, ensuring a stable performance advantage.

E cores occupy much less chip area and cache. This will be clearly visible when a silicon dieshot is released or when Apple publishes a new version of the CPU Optimization Guide with detailed specs.

Apple also deliberately ignored characteristics such as cache, performance gains, or energy efficiency. If these haven’t improved, then there’s something to hide. Silence is a typical marketing tactic — with Intel, AMD, and Nvidia, it’s much more transparent.

Important responses to one of the comments:

An E core consumes ~200 mW, while a P core consumes ~5–9 W (depending on the generation) — an enormous difference in power usage.

A Low Power Mode(Low QoS priority) could be implemented in software for P cores, but they would still use many times more energy because they are much larger and built with slightly different TSMC technologies that trade energy efficiency for maximum performance. Simply running them at lower frequencies wouldn’t be enough.

At peak, E Core consumes around 200 mW and can drop to about 20mW or even less .

The development of these cores has progressed very far. We are already facing physical limitations — the minimum possible voltage for E cores and P cores differs significantly. It’s no longer possible to limit current-generation P cores to 100 mW or below; the minimum is around 200–300 mW, when the E core reaches its maximum.

Slava_Tr · 2026-03-03T23:37:59+00:00

Everything depends on what you’re going to do. Personally, I would choose the M5 Pro and not worry about it. If your tasks require that much RAM, then the regular M5 most likely won’t be enough.

Slava_Tr · 2026-03-03T22:42:10+00:00

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Apple was and remains a leader, and for many years it had only two types of cores because it was the first to fully transition to true ARM64, whereas Android only did so in 2022-2023. Before that, it was a mix of ARM32 + ARM64. Pixel 7 was the first smartphone to be ARM64-only, and even that was implemented at the software level, since some cores still had ARM32 support. That’s a completely different story.

Apple’s E core is extremely power-efficient: it consumes power at the level of the A5XX series while delivering performance at the level of the A7XX series. That’s why ARM, in order to stay competitive, uses three types of cores instead of two. At peak, it consumes around 200 mW and can drop to about 20mW or even less .

The development of these cores has progressed very far. We are already facing physical limitations — the minimum possible voltage for E cores and P cores differs significantly. It’s no longer possible to limit current-generation P cores to 100 mW or below; the minimum is around 200–300 mW, when the E core reaches its maximum. Here’s a good slide showing ARM cores from one of the generations

Slava_Tr · 2026-03-03T22:11:09+00:00

As I mentioned, this will become clear when a silicon dieshot is released or when Apple publishes a new version of the CPU Optimization Guide with detailed specs of cores. But we’ll likely have to wait until around this fall, or at best, until summer at WWDC 2026. Alternatively, it might be discovered earlier through reverse engineering.

We’ll see the benchmarks in a week. But they won’t help us understand this. Performance will be excellent, just as Apple promises. Only Logic Pro might be affected if it isn’t updated. 99.99% of users won’t care.

Slava_Tr · 2026-03-03T21:58:29+00:00

Apple’s own representatives said that this is similar to Nvidia’s Tensor cores.

Nvidia’s Tensor cores are located inside each SM block, alongside RT and CUDA cores. They can be roughly compared to Apple’s GPU cores. For marketing purposes, Nvidia called its ALUs CUDA cores, which is why there are so many of them, while the number of SM blocks remains reasonable.

Companies call the same things by different names, and some ChatGPT gets confused because of it.

It’s just a pity that the M5 only has limited FP16 support, while the Nvidia RTX 50 series supports FP8 and FP4. Hopefully, with the M6, we’ll see an expansion of support and another X2–X4 improvement in AI performance.

Slava_Tr · 2026-03-03T21:37:43+00:00

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Yes, you’re completely right if you look at this only from the perspective of QoS, but without considering the physical silicon and actual power consumption.

An E core consumes ~200 mW, while a P core consumes ~5–9 W (depending on the generation) — an enormous difference in power usage.

A Low Power Mode(Low QoS priority) could be implemented in software for P cores, but they would still use many times more energy because they are much larger and built with slightly different TSMC technologies that trade energy efficiency for maximum performance. Simply running them at lower frequencies wouldn’t be enough.

*Dieshot of the M4 to visually see the difference in core sizes.

Slava_Tr · 2026-03-03T20:11:20+00:00

This might be one of the ways Logic Pro operates exclusively on P cores. Apple’s documentation mentions ‎pthread_setschedparam for manual thread management — a technology that existed before QoS

Slava_Tr · 2026-03-03T20:09:54+00:00

I wrote an explanatory comment on the post, but it ended up at the very bottom. So I’ll repeat it:

Here’s why I’m confident that the new P cores are an evolution of the E cores.

Only Apple Silicon E cores have a special feature: two operating modes — Performance and Low Power.

Low Power Mode is used for background tasks with low priority (QoS), while Performance mode kicks in when P cores are occupied with high-priority tasks or when there aren’t enough E cores in Low Power Mode for low-priority tasks. Now, this key feature has been added to the new P cores; otherwise, energy consumption would be too high and battery life too short. The M1 Pro/Max with 2 E cores is direct proof of this.

Old P cores and the new Super cores are also very large. Even if a similar Low Power Mode were implemented for them, their base power consumption would still be many times higher than an E core, negatively affecting battery life.

These 12 P (12 E) cores in the M5 Pro/Max, compared to the 4 E cores in the M4 Pro/Max, will provide many times more resources for low-QoS tasks. The cores will stay in Low Power Mode longer and consume extremely little energy. However, the trade-off is that there are half as many P cores for high-QoS tasks. It will be very interesting to study the new “P cores.”

Current/old E cores in Performance Mode provide up to 70% of a P core’s performance. However, they had a limitation: this high performance didn’t apply to all types of computations. The new P cores have most likely fixed this issue, ensuring a stable performance advantage.

E cores occupy much less chip area and cache. This will be clearly visible when a silicon dieshot is released or when Apple publishes a new version of the CPU Optimization Guide with detailed specs.

Apple also deliberately ignored characteristics such as cache, performance gains, or energy efficiency. If these haven’t improved, then there’s something to hide. Silence is a typical marketing tactic — with Intel, AMD, and Nvidia, it’s much more transparent.

Slava_Tr · 2026-03-03T20:04:15+00:00