New 96GB–512GB Local AI Hardware Guides

HighVRAM has expanded its large-memory local-AI buyer cluster with three new guides: AMD Instinct MI300X 192GB, Mac Studio M5 Ultra with up to 512GB, and a direct M5 Ultra versus RTX PRO 6000 Blackwell comparison. Together they cover dedicated HBM, dedicated CUDA workstation VRAM and shared unified-memory paths for models that exceed ordinary desktop GPU capacity.

These are capacity-planning guides, not a speed ranking. Published memory capacity and bandwidth do not establish runtime compatibility, prompt-processing speed, generation rate, reliability or value for a particular model.

Three large-memory paths at a glance

Path	Published memory	Published bandwidth	Planning distinction
RTX PRO 6000 Blackwell Workstation Edition	96GB GDDR7 with ECC	1,792GB/s	Dedicated CUDA workstation GPU; requires a qualified host system
AMD Instinct MI300X	192GB HBM3 with full-chip ECC	5.3TB/s peak theoretical	Passive OAM datacenter accelerator; requires a qualified server platform and ROCm support
Mac Studio M5 Ultra	96GB unified; configurable to 256GB or 512GB	1.2TB/s	Complete desktop with one pool shared by CPU, GPU, macOS and applications

Manufacturer specifications. The form factors, memory architectures, power scopes and software stacks differ.

What changes for Qwen3.5-122B?

The official Qwen3.5-122B-A10B GPTQ-Int4 files total 78.864GB, so they fit by files on a 96GB-class device or unified-memory system, but with limited headroom. The official 127.163GB FP8 checkpoint exceeds 96GB and fits by files on one 192GB MI300X or a 256GB M5 Ultra configuration. The 250.173GB BF16 checkpoint is a file boundary at 256GB shared memory and does not fit on one MI300X; it needs a larger shared pool or an explicitly supported multi-device plan.

What changes for Qwen3.5-397B?

The smallest listed official artifact, 235.708GB GPTQ-Int4, exceeds one 192GB MI300X or 96GB RTX PRO 6000. It is a tight file boundary on a 256GB Mac and a practical capacity candidate on 512GB. The 406.152GB FP8 checkpoint fits by files only in the 512GB Mac class among these one-system examples. Multiple accelerators can provide sufficient aggregate memory, but separate device pools require runtime-supported placement and per-device headroom.

The software decision comes first

RTX PRO 6000: verify the exact driver, CUDA toolkit, Blackwell kernels, model architecture and quantization.
MI300X: verify the exact ROCm release, container, gfx942 kernels, OAM platform, firmware and multi-accelerator topology.
M5 Ultra: verify an Apple-silicon runtime such as MLX or Metal supports the exact model, quantization, hybrid attention, MoE and multimodal components.

A model file fitting within the advertised capacity is only the first gate. Record context, modality, batch size, concurrency, device placement, offload, peak device/system memory, time to first token, prompt-processing rate, generation rate and errors.

New 32GB-versus-96GB Blackwell comparison

The upgraded RTX 5090 versus RTX PRO 6000 Blackwell guide now applies exact Qwen3.5-27B and 35B-A3B files to both cards. It identifies the 27B Q8-plus-projector pair as an unsafe 2.477GB file-margin boundary on RTX 5090 and separates that capacity result from bandwidth, ECC, MIG, support and measured performance.

Use the expanded buyer path

Start with the 96GB-to-1TB Qwen3.5 hardware comparison, then open the exact 122B or 397B artifact guide. Before buying, use the workload test and contribute measured results through the benchmark builder.

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Primary sources and limits

Published October 25, 2026. File totals were summed from the cited official Qwen repositories. Hardware specifications are manufacturer-published. HighVRAM has not independently benchmarked every system, runtime or workload. Fit does not establish speed, quality, reliability or value.