Short answer: DeepSeek’s official full-precision repository displays 3.56GB for DeepSeek-R1-Distill-Qwen-1.5B. A compact quantized artifact can target small GPUs and CPU-first systems, but context, KV-cache precision, runtime state and the exact conversion still determine the real fit. The published 131,072-position limit is not a promise that a 4GB device can hold a full 128K allocation.
Model identity matters: this is the dense 1.5B distillation based on Qwen2.5-Math-1.5B. It is not the original DeepSeek-R1 671B-total/37B-active MoE model, and memory guidance for one does not transfer to the other.
DeepSeek-R1-Distill-Qwen-1.5B at a glance
| Published field | Value | Planning meaning |
|---|---|---|
| Official repository display | 3.56GB | Full-precision repository class, not peak runtime memory |
| Base model | Qwen2.5-Math-1.5B | Dense Qwen-family distillation |
| Layers | 28 | Multiplies per-sequence cache state |
| Attention / KV heads | 12 / 2 | Grouped-query attention reduces KV state |
| Head dimension | 128 | Derived from 1,536 hidden size ÷ 12 heads |
| Maximum positions | 131,072 | Architectural limit, not a guaranteed hardware fit |
Raw weight floors by nominal precision
| Nominal precision | Raw 1.5B floor | What it means |
|---|---|---|
| 4-bit | 0.75GB | Small-device starting point; artifact metadata and runtime memory are extra |
| 5-bit | 0.9375GB | More weight fidelity with modest additional storage |
| 6-bit | 1.125GB | Still compact, but not the complete allocation |
| 8-bit | 1.5GB | Leaves room on 4GB for cache and runtime only at bounded workloads |
| 16-bit | 3GB | Consistent with the official 3.56GB repository display before runtime state |
These are label arithmetic floors, not exact GGUF file sizes or measured allocations. Quantization formats add scales, metadata and alignment, while runtimes add buffers and temporary state.
KV-cache payload at 8K, 32K and 128K
For one sequence with FP16 key/value entries, the transparent architecture calculation is 2 × 28 layers × 2 KV heads × 128 head dimension × 2 bytes × token slots.
| Allocated token slots | Illustrative FP16 K+V payload | Planning consequence |
|---|---|---|
| 8,192 | 0.21875GiB | Usually secondary to weights, but not zero |
| 32,768 | 0.875GiB | Material on a 2GB–4GB device |
| 131,072 | 3.5GiB | Exceeds a 4GB plan once any weights and overhead are included |
This is architecture arithmetic, not measured peak memory. Cache quantization, paging, batch size, concurrency, alignment and runtime implementation can change the allocation.
Can DeepSeek 1.5B run on a 2GB GPU?
A compact 4-bit or 5-bit artifact can be a plausible starting point, but 2GB is workload-sensitive. Keep context and concurrency modest, verify the exact runtime’s GPU offload behavior, and expect CPU or shared-memory assistance when the complete allocation does not fit. Loading successfully is not proof that long prompts or generation peaks will remain on-device.
Is 4GB enough?
Four gigabytes gives much more practical room for a compact conversion, an 8-bit path, or a moderate cache. It still cannot combine the full 128K illustrative FP16 cache with the weights and runtime overhead. Treat 4GB as a useful small-model tier, not as an unlimited-context tier.
What do 6GB and 8GB change?
Six or eight gigabytes can provide more space for higher-precision weights, longer context, larger batches or runtime buffers. The extra capacity does not prove faster generation: memory bandwidth, compute, software kernels and CPU/GPU transfer behavior still matter. A well-supported 4GB device may outperform a poorly supported larger pool for a specific stack.
CPU and unified-memory use
This size is also a realistic CPU-first or integrated-memory candidate. Use the same discipline: count total system memory after the operating system and other applications, confirm whether the runtime preallocates the maximum cache, and measure resident memory during a representative long request. “Runs on CPU” says nothing by itself about latency, tokens per second or energy use.
A reproducible fit test
- Record the exact repository, revision, conversion, quantization and file size.
- Record runtime and version, device model, visible memory and offload settings.
- Test a short prompt first, then the intended context and output limit.
- Measure peak device memory and host memory separately.
- Repeat after a cold start; do not count only the post-load idle value.
- Record prompt-processing speed, generation speed and time to first token separately.
- Evaluate answer quality on representative tasks; fit is not capability.
Sources and limits
- Official DeepSeek-R1-Distill-Qwen-1.5B repository
- Official model configuration
- Official DeepSeek-R1 model table and usage guidance
- HighVRAM methodology
Reviewed October 25, 2026. Repository display and architecture fields come from DeepSeek’s official pages. Weight and cache figures are transparent planning arithmetic, not measured peak-memory claims. HighVRAM has not independently benchmarked every conversion or runtime. Capacity does not establish speed, reasoning quality or value.
Need a larger small-device model?
Compare the Qwen3-4B VRAM guide for official 2.50GB–4.28GB files, 32K context geometry and 4GB/6GB/8GB paths.
Comparing compact text models? Read the Gemma 3 1B VRAM guide alongside this 1.5B DeepSeek distill without assuming equal architecture or quality.