This week, Xiaomi launched an in-house flagship chipset for smartphones and tablets, the Xring O1. It’s featured on the Xiaomi 15S Professional and the Xiaomi Pad 7 Extremely. Some expressed doubt as to how a lot Xiaomi really did right here – in spite of everything, the O1 makes use of commonplace CPU and GPU cores from the ARM elements bin. The group at Geekerwan did a deep dive and found that that is really a closely custom-made chip.
The Xring O1 is fabbed on the TSMC N3E node, the identical as MediaTek’s Dimensity 9400. And it makes use of a few of the similar elements too – Cortex-X925 and A720 for the CPU and Immortalis-G925 for the GPU. Nonetheless, the design may be very, very completely different.
For starters, there are two Cortex-X925 prime cores on board, not only one. And Xiaomi passed over the X4, as a substitute choosing two variants of the Cortex-A720 for the large and mid-cores. And it added two A520 cores as a security web.
These Cortex-A720 cores are an attention-grabbing aspect of the O1 design. There are two clusters – 4 cores designed for prime efficiency and two extra optimized for effectivity. Within the die shot proven within the video you possibly can see that the 2 effectivity A720 cores are bodily completely different from the 4 efficiency A720 cores – they’re a bit bigger and are restricted to a a lot decrease clock pace (1.9GHz vs. 3.4GHz).
This enables the chipset to change between cores to match efficiency necessities whereas utilizing as little energy as attainable. The low-power A720 cores are so good that the 2 A520 cores could not have been vital.
The top result’s fairly spectacular – Xiaomi’s Xring O1 beats the Dimensity 9400 when it comes to CPU efficiency and energy effectivity. It’s not fairly on the extent of Qualcomm’s Snapdragon 8 Elite, however it’s not far off both.
The Xring O1 is pretty small at 109mm² – it’s about the identical measurement because the Apple A18 Professional. Nonetheless, each the Xiaomi and Apple chips use exterior modems, whereas the Dimensity 9400 and Snapdragon 8 Elite have built-in modems. This explains a part of the dimensions discrepancy (and creates a difficulty that we’ll come to afterward).
The Xring group configured the on-chip reminiscence in an attention-grabbing means – most chipsets nowadays have a number of megabytes of System Degree Cache (SLC), which is the final cease earlier than having to fetch information from RAM.
The O1 has no SLC. As an alternative, Xiaomi configured the CPU with a number of cache – 16MB of L3 shared between all 10 cores, 2MB L2 every for the X925 cores and 1MB L2 for every of the A720 cores. The GPU has 4MB of cache and the NPU has 10MB – have a look at it, it’s large!
The NPU is just not an ARM design however as a substitute a customized Xiaomi creation. The 6-core NPU takes up nearly as a lot room on the chip because the CPU. The ISP can also be created by Xiaomi, a fourth era design. Earlier generations have been featured as separate chips on the motherboards of Xiaomi flagships, however having it inbuilt is extra environment friendly.
Now we come to the GPU – a 16-core Immortalis-G925 from ARM. The Xring group did a superb job configuring the CPU, however it might have gotten it mistaken with the GPU. For one, it’s fairly massive – the Dimensity 9400 has a 12-core G925.
Additionally, the Geekerwan group speculates that the omission of the SLC has damage GPU effectivity – it’s fairly quick, however it makes use of extra energy than the Dimensity GPU at peak efficiency.
The extra environment friendly CPU mixed with the truth that the GPU hardly ever runs at full tilt makes for fairly good general effectivity in real-life gaming exams. Nonetheless, that is an space that needs to be improved in future designs.
Another downside with effectivity – having an exterior modem (a MediaTek T800 on this case) makes use of extra energy, which hurts Xiaomi 15S Professional’s standby endurance. That is without doubt one of the causes Apple labored so laborious on having an built-in 5G modem (which made its debut with the iPhone 16e).
Xiaomi isn’t there but, however it took step one – it launched its first 4G modem with the Xring T1, the chipset for the revamped Xiaomi Watch S4. 5G is rather a lot more durable than 4G (it took Apple years to get it proper), however it could be one other main milestone in the direction of vertical integration for Xiaomi.
With that, we depart you to observe the video, which works into nice element on how the Xring O1 is constructed and the way it performs:
