magnum-v4-27b
anthracite-org/magnum-v4-27bmagnum-v4-27b at Q4_K_M is exactly 16,645,381,728 bytes (15.50 GiB / 16.65 GB) — an effective 4.891 bits per weight, not the nominal 4. Its KV cache at 32K is 6.56 GiB, not the 11.50 GiB a flat formula predicts.
Shipped quantizations
| Quant | Size● | Exact bytes● | Effective bpw● | Tensors● | Publisher |
|---|---|---|---|---|---|
| IQ2_XS | 7.82 GiB | 8,399,715,936 | 2.468 | — | bartowski |
| IQ2_S | 8.06 GiB | 8,652,160,608 | 2.542 | — | bartowski |
| IQ2_M | 8.75 GiB | 9,398,877,792 | 2.762 | — | bartowski |
| Q2_K | 9.73 GiB | 10,449,575,520 | 3.070 | — | bartowski |
| Q2_K_L | 10.00 GiB | 10,735,271,520 | 3.154 | — | bartowski |
| IQ3_XS | 10.76 GiB | 11,550,629,472 | 3.394 | — | bartowski |
| Q3_K_S | 11.33 GiB | 12,169,059,936 | 3.576 | — | bartowski |
| IQ3_M | 11.60 GiB | 12,454,829,664 | 3.659 | — | bartowski |
| Q3_K_M | 12.50 GiB | 13,424,647,776 | 3.945 | — | bartowski |
| Q3_K_L | 13.52 GiB | 14,519,361,120 | 4.266 | — | bartowski |
| IQ4_XS | 13.80 GiB | 14,814,420,576 | 4.353 | — | bartowski |
| Q4_0 | 14.60 GiB | 15,681,461,856 | 4.608 | — | bartowski |
| Q4_K_S | 14.66 GiB | 15,739,264,608 | 4.625 | — | bartowski |
| Q4_K_M | 15.50 GiB | 16,645,381,728 | 4.891 | — | bartowski |
| Q4_K_L | 15.77 GiB | 16,931,077,728 | 4.975 | — | bartowski |
| Q5_K_S | 17.59 GiB | 18,884,206,176 | 5.549 | — | bartowski |
| Q5_K_M | 18.08 GiB | 19,408,117,344 | 5.703 | — | bartowski |
| Q5_K_L | 18.34 GiB | 19,693,813,344 | 5.787 | — | bartowski |
| Q6_K | 20.81 GiB | 22,343,523,936 | 6.565 | — | bartowski |
| Q6_K_L | 21.08 GiB | 22,629,219,936 | 6.649 | — | bartowski |
| Q8_0 | 26.95 GiB | 28,937,387,616 | 8.502 | — | bartowski |
| F162 shards | 50.72 GiB | 54,462,021,184 | 16.002 | — | bartowski |
KV cache by context
| Context | KV cache (f16)● | Flat formula | Overstated by | Full / windowed / recurrent |
|---|---|---|---|---|
| 4,096 | 1.44 GiB | 1.44 GiB | — | 23 / 23 / 0 |
| 8,192 | 2.25 GiB | 2.88 GiB | 1.28× | 23 / 23 / 0 |
| 16,384 | 3.68 GiB | 5.75 GiB | 1.56× | 23 / 23 / 0 |
| 32,768 | 6.56 GiB | 11.50 GiB | 1.75× | 23 / 23 / 0 |
| 65,536 | 12.31 GiB | 23.00 GiB | 1.87× | 23 / 23 / 0 |
| 131,072 | 23.81 GiB | 46.00 GiB | 1.93× | 23 / 23 / 0 |
23 of 46 layers cache only a 4,096-token window rather than the full context, on a period of 2. Figures assume the default configuration; --swa-full disables the saving entirely.
Compare with
Will it run on your card?
Why other calculators give a different number
A parameters × bits ÷ 8 estimate puts Q4_K_M at roughly 14.26 GiB. The real file is 15.50 GiB, because a quantization is a mixture and some tensors are always kept at higher precision. The larger discrepancy is the cache: a flat formula gives 11.50 GiB at 32K context where the real figure is 6.56 GiB, because most of this model's layers cache a fixed window rather than the whole context.
Architecture
Questions people ask
- How much VRAM does magnum-v4-27b need?
- Q4_K_M is exactly 16,645,381,728 bytes (15.50 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
- How large is magnum-v4-27b's KV cache?
- 6.56 GiB at 32K context with an f16 cache, computed per layer. Quantizing the cache to q8_0 roughly halves it, which is often the difference between a context length fitting and not.
- Which quantization of magnum-v4-27b should I use?
- Q4_K_M is the usual default. Pick the largest quantization that fits your card at the context you actually need — the table above gives exact sizes for every one published.