Step 3.5 Flash REAP 121B A11B — Hardware Requirements & GPU Compatibility
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123 downloads
9 likesSpecifications
- Publisher
- Cerebras
- Parameters
- 121.0B
- Architecture
- Step3p5ForCausalLM
- Context Length
- 262,144 tokens
- Vocabulary Size
- 128,896
- Release Date
- 2026-02-25
- License
- Other
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HuggingFace
How Much VRAM Does Step 3.5 Flash REAP 121B A11B Need?
Select a quantization to see compatible GPUs below.
| Quantization | Bits | VRAM | + Context | File Size | Quality |
|---|---|---|---|---|---|
| IQ4_XS | 4.30 | 71.5 GB | — | 65.02 GB | Importance-weighted 4-bit, compact |
Which GPUs Can Run Step 3.5 Flash REAP 121B A11B?
IQ4_XS · 71.5 GBStep 3.5 Flash REAP 121B A11B (IQ4_XS) requires 71.5 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 93+ GB is recommended. No single GPU has enough memory — multi-GPU or cluster setups are needed.
Which Devices Can Run Step 3.5 Flash REAP 121B A11B?
IQ4_XS · 71.5 GB5 devices with unified memory can run Step 3.5 Flash REAP 121B A11B, including NVIDIA DGX H100, NVIDIA DGX A100 640GB.
Related Models
Frequently Asked Questions
- How much VRAM does Step 3.5 Flash REAP 121B A11B need?
Step 3.5 Flash REAP 121B A11B requires 71.5 GB of VRAM at IQ4_XS.
VRAM = Weights + KV Cache + Overhead
Weights = 121.0B × 4.3 bits ÷ 8 = 65 GB
KV Cache + Overhead ≈ 6.5 GB (at 2K context + ~0.3 GB framework)
VRAM usage by quantization
IQ4_XS71.5 GB- Can NVIDIA GeForce RTX 5090 run Step 3.5 Flash REAP 121B A11B?
No — Step 3.5 Flash REAP 121B A11B requires at least 71.5 GB at IQ4_XS, which exceeds the NVIDIA GeForce RTX 5090's 32 GB of VRAM.
- Can I run Step 3.5 Flash REAP 121B A11B on a Mac?
Step 3.5 Flash REAP 121B A11B requires at least 71.5 GB at IQ4_XS, which exceeds the unified memory of most consumer Macs. You would need a Mac Studio or Mac Pro with a high-memory configuration.
- Can I run Step 3.5 Flash REAP 121B A11B locally?
Yes — Step 3.5 Flash REAP 121B A11B can run locally on consumer hardware. At IQ4_XS quantization it needs 71.5 GB of VRAM. Popular tools include Ollama, LM Studio, and llama.cpp.
- How fast is Step 3.5 Flash REAP 121B A11B?
At IQ4_XS, Step 3.5 Flash REAP 121B A11B can reach ~41 tok/s on AMD Instinct MI300X. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.
tok/s = (bandwidth GB/s ÷ model GB) × efficiency
Example: AMD Instinct MI300X → 5300 ÷ 71.5 × 0.55 = ~41 tok/s
Estimated speed at IQ4_XS (71.5 GB)
AMD Instinct MI300X~41 tok/sNVIDIA H100 SXM~31 tok/sAMD Instinct MI250X~25 tok/sReal-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.
- What's the download size of Step 3.5 Flash REAP 121B A11B?
At IQ4_XS, the download is about 65.02 GB.
- Which GPUs can run Step 3.5 Flash REAP 121B A11B?
No single consumer GPU has enough VRAM to run Step 3.5 Flash REAP 121B A11B at IQ4_XS (71.5 GB). Multi-GPU or professional hardware is required.
- Which devices can run Step 3.5 Flash REAP 121B A11B?
5 devices with unified memory can run Step 3.5 Flash REAP 121B A11B at IQ4_XS (71.5 GB), including Mac Pro M2 Ultra (192 GB), Mac Studio M2 Ultra (192 GB), Mac Studio M4 Max (128 GB), NVIDIA DGX A100 640GB. Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.