M5 Ultra
Apple's first processor built on a quad-chip fusion architecture, connecting two M5 Max dies via the UltraFusion interconnect. It supports up to 512 GB of unified memory and 1.2 TB/s memory bandwidth, enabling local inference of models with hundreds of billions of parameters.
Core Facts
Under the M5 Ultra's 1.2 TB/s bandwidth, the theoretical speed of a 100 GB quantized model is approximately 12 tokens/s, a 200 GB model approximately 6 tokens/s, and a 300 GB model approximately 4 tokens/s.
The M5 Ultra's peak AI compute performance is more than 4x higher than that of the M3 Ultra.
The UMA memory bus bandwidth of Apple's M2 Ultra has reached 800 GB/s.
Timeline (last 90 days)
A Reddit user ran benchmark tests of multiple models including GLM-5.3-Flash on an M5 Ultra 256GB 80-core Mac Studio.
If the GPU is already a bottleneck at the 256GB configuration, doubling the memory to 512GB will not improve GPU compute, and loading larger models will instead result in slower inference.
The M5 Ultra's 80-core GPU is the highest consumer-grade Apple Silicon configuration, but its floating-point compute still lags behind data center-grade GPUs such as the NVIDIA H100/H200 by an order of magnitude.
The user found that the M5 Ultra's GPU compute power is insufficient relative to its large 256GB memory capacity.
In the Blender public benchmark rankings, the Mac Studio equipped with the M5 Ultra scored between the RTX 5090 and the RTX 4090.
The M5 Ultra's BF16 compute performance is equivalent to only half of a DGX Spark.
UP host 小蛋糕's final decision is not to buy the M5 Ultra and to keep the Spark, primarily because of the need to run AI experiments and because the CUDA platform libraries are ready to use out of the box.
The M5 Ultra's FP8 and FP4 floating-point compute performance is identical to its BF16 performance, and the gap with the Spark narrows noticeably when dropping to FP4 precision.
The M5 Ultra's memory capacity is more than five times that of the RTX Pro 6000, but its memory bandwidth is only about two-thirds of the latter.
If bandwidth reached 2.4 TB/s, the theoretical speed ceiling for a 100 GB model could reach 24 tokens/s, a 60 GB model 40 tokens/s, and a 35 GB model close to 69 tokens/s.
40 more timeline events
All Facts (20)
Under the M5 Ultra's 1.2 TB/s bandwidth, the theoretical speed of a 100 GB quantized model is approximately 12 tokens/s, a 200 GB model approximately 6 tokens/s, and a 300 GB model approximately 4 tokens/s.
65%VerifiedThe M5 Ultra's peak AI compute performance is more than 4x higher than that of the M3 Ultra.
65%VerifiedThe UMA memory bus bandwidth of Apple's M2 Ultra has reached 800 GB/s.
65%VerifiedThe Mac Studio M5 Ultra starts at $5,499, with up to 512GB of memory and memory bandwidth of 1.2TB per second, with the 512GB version expected to ship in late October.
80%VerifiedThe Mac mini M6 starts at $899, with up to 32GB of unified memory, going on sale September 22, 2026.
75%VerifiedThe M5 Ultra is very likely to adopt UltraFusion dual-chip interconnect packaging technology, combining two M5 Max-level chips into a single logical unit.
65%Partially VerifiedThe UltraFusion inter-chip bandwidth of the M5 Ultra has increased from approximately 2.5 TB/s on the M3 Ultra to 4.4 TB/s, with a 6x improvement in connection density.
70%Partially VerifiedUnder heavy GPU load, the M3 Ultra consumes approximately 100 W, while the M5 Ultra surges to over 400 W.
65%Partially VerifiedThe M5 embeds a dedicated Neural Accelerator for matrix multiplication inside every GPU core.
65%Partially VerifiedThe new Mac Studio uses a unified memory design, with the 128 GB memory version starting at RMB 19,999 for the domestic Chinese market and the 512 GB version starting at RMB 46,999.
65%Partially Verified统一内存架构使CPU、GPU与NPU共享同一块内存池，避免数据在处理单元间反复搬运的开销
65%UnverifiedIf bandwidth reached 2.4 TB/s, the theoretical speed ceiling for a 100 GB model could reach 24 tokens/s, a 60 GB model 40 tokens/s, and a 35 GB model close to 69 tokens/s.
60%UnverifiedThe M5 Ultra version of the Mac Studio is equipped with up to 80-core GPU and up to 512GB of unified memory
60%UnverifiedCompared to the M3 Ultra, the M5 Ultra shows approximately 33.5% improvement in Geekbench single-core and approximately 32.5% improvement in multi-core scores.
60%UnverifiedIn the time-to-first-token test on a 70-billion-parameter model, the M3 Ultra took 31.6 seconds while the M5 Ultra took only 7.7 seconds, achieving approximately 4.1x, close to Apple's claimed 4.3x.
60%UnverifiedFor small-to-medium models that fit within 32 GB of VRAM, the RTX 5090 leads (approximately 45% on Gemma 4 12B and over 75% on GPT-OSS 20B), but the lead on Qwen 3 27B drops from 47% at Q4 to 23% at Q8.
60%UnverifiedThe M5 Ultra's multi-core performance score is nearly twice that of the 9950X3D, and it maintains the same advantage in Cinebench 2026.
60%UnverifiedOn the 70-billion-parameter DeepSeek R1 distillation model, because the model overflows the RTX 5090's 32 GB of VRAM, the M5 Ultra is more than 20 times faster than the 5090.
60%UnverifiedIn AmorphousDiskMark tests, the M5 Ultra achieves sequential read speeds of 14,888 MB/s and write speeds approaching 20,000 MB/s, while the M3 Ultra reads at approximately 6,500 MB/s and writes at 2,700 MB/s.
60%UnverifiedThe Mac Studio is equipped with M-series chips, such as the M2 Max, M2 Ultra, and subsequent updated versions.
60%