Apple drops top‑RAM M3 Ultra Mac Studio as M5 Max's 18‑core CPU edges M4 Max by 10%

Apple’s decision to drop the 512 GB unified‑memory option from the M3 Ultra Mac Studio reflects a broader supply‑chain squeeze that is reshaping Apple’s high‑end desktop lineup. 9to5Mac notes that the top‑RAM configuration, which was a headline feature at the product’s launch a year ago, is no longer listed on Apple’s configurator, leaving the 256 GB option as the maximum for the M3 Ultra model. The outlet attributes the change to “global supply constraints … high memory needs for servers powering AI,” a shortfall that appears to be affecting other manufacturers that rely on the same DRAM suppliers. By contrast, the newer M5 Max SoC, which debuted in the latest Mac Studio refresh, still caps at 128 GB of unified memory, but it compensates with a modest CPU uplift that pushes its performance roughly 10 % ahead of the M4 Max, according to a benchmark leak reported by Wccftech.

The memory reduction has practical implications for developers and enterprises that target on‑device AI workloads. Apple’s original press release for the M3 Ultra highlighted the ability to run “large language models (LLMs) with over 600 billion parameters entirely in memory,” a claim that hinges on the availability of the full 512 GB pool. With only 256 GB now possible, the ceiling for in‑memory model size drops dramatically, potentially forcing customers to offload portions of their workloads to external GPUs or cloud services. MacRumors, citing Apple’s current ordering page, confirms that the 256 GB configuration remains the highest RAM offering across the Mac Studio family, still ahead of the M2 Ultra‑based Mac Pro’s 192 GB limit but well below the original M3 Ultra promise.

Performance‑wise, the M5 Max’s 18‑core CPU—six efficiency and twelve performance cores—delivers a “small 10 % performance bump” over the M4 Max in both single‑threaded and multi‑threaded benchmarks, as detailed by Wccftech. While the gain is modest, the M5 Max’s architecture enables it to outpace the workstation‑class M3 Ultra in the same tests, marking the first time an Apple‑silicon desktop has eclipsed the M3 Ultra’s raw compute despite the latter’s larger core count and higher memory ceiling. The improvement underscores Apple’s shift toward incremental CPU enhancements rather than dramatic leaps, a strategy that aligns with the company’s current focus on balancing performance with the realities of component scarcity.

From a market perspective, the removal of the 512 GB option may signal a recalibration of Apple’s pricing and positioning for its professional‑grade Macs. The M3 Ultra Mac Studio, originally marketed as the most powerful personal computer for AI‑intensive tasks, now shares its top‑memory tier with the M2 Ultra‑based Mac Pro, which caps at 192 GB. This convergence could narrow the differentiation between Apple’s desktop offerings, potentially nudging enterprise buyers toward alternative platforms that can guarantee larger memory footprints. At the same time, the M5 Max’s modest CPU edge and its continued support for up to 128 GB of RAM may make it an attractive compromise for customers who prioritize compute speed over sheer memory capacity.

Overall, Apple’s adjustment to the M3 Ultra’s memory options illustrates how supply‑chain pressures are forcing the company to temper its most ambitious specifications. The shift does not diminish the M3 Ultra’s status as the Mac Studio with the highest configurable RAM—still double the M2 Ultra’s 192 GB—but it does curtail the extreme use cases that Apple originally touted. As the industry watches Apple navigate these constraints, the modest performance gains of the M5 Max suggest that future gains will likely come from architectural refinements rather than headline‑grabbing memory expansions.