Meet the Arm Mali G2-Ultra
Before we get into the AI enhancements found in this year’s Mali graphics chips, we need to dive into the core architecture and portfolio change in the G2 series. If you’re after the raw performance numbers, Arm lists quite a range of results. Gaming performance increases by 9% (Honkair Starrail) to 14% (Fortnite) when comparing the 14-core Mali G1-Ultra reference platform to the G2-Ultra equivalent (which also features a 1.53GHz versus 1.70GHz shader core clock difference). At the upper end, Arm expects we could see 17-20% performance improvements in the most demanding mobile graphics benchmarks.
Generation-on-generation improvements in general rasterization are reasonably modest, but that doesn’t mean things haven’t changed. The execution engines have been revamped to support much larger desktop-class shaders, with up to twice the registers per warp (now 128 instead of 64) and also more dynamic allocation, supporting 16 warp-wide steps from 16 to 128 registers. This allows advanced graphical shader technologies like Unreal 5’s Lumen and Nanite to run without register spilling and the associated performance drops from reaching out to DRAM. This marks Arm’s biggest change to Mali in seven generations.
NX explained — AI inside the GPU
OK, those performance metrics are all very welcome, but Arm’s biggest announcement is undoubtedly the introduction of native AI support via the new NX neural accelerator. NX is a tightly integrated, optional hardware accelerator that sits inside the GPU’s shader core to run neural graphics tasks while costing as little as 1W in power.
The tightly integrated neural accelerator supports INT8 and INT16 operations and includes its own motion engine processing block, which we’ll touch on later. The NX core also has its own clock frequency operating at up to 2x the main GPU clock using the same voltage, and shares memory with the rest of the GPU subsystem to ensure memory coherency.
The makings of a next-gen mobile processor
Putting this all together, there’s an even wider range of Mali configuration options than ever before, and it’s all getting rather overly complicated. As before, the Ultra range offers the highest core count, between 10 and 24 shader cores, to scale all the way up to laptop-class performance. The Ultra branding is appended to the NX brand, as it must contain at least one NX core, and there’s also an opinion to include ray-tracing support, though this doesn’t change the naming scheme. The G2-Premium range is a mid-tier mobile option with six to nine shader cores, optional NX branding if at least one such core is present, and optional ray tracing. Finally, the budget “Pro” segment caters to five cores and below, again with optional AI acceleration.
All in all, there are five possible configuration groups: the G2-Ultra NX, G2-Premium NX, G2-Premium, G2-Pro NX, and G2-Pro, with some variation within these brackets. Confused? Me too. In any case, we’re likely looking at around 12-core versions for premium smartphone platforms, no doubt with roughly half as many NX cores and ray-tracing support.
While bringing “fake frames” to mobile will undoubtedly be a controversial topic in some circles, I’ll admit I’m hesitant to see developers rely on AI techniques to compensate for a lack of traditional optimization and simply rush products to market. Still, mobile perhaps stands to benefit far more from AI-assisted graphics rendering than desktop and console players, owing to our more conservative power budgets for high-end rendering.
If Arm’s claims that titles look just as good but run more smoothly, and our batteries can game for longer, turn out to be true, then I’m all for it.
