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Open models at full precision, and the memory they need.

Running an open model at full 16-bit precision takes about 2 GB of GPU memory per billion parameters for the weights alone: Qwen3.5 397B needs about 794 GB in BF16, which one Wick Ultra's 1,152 GB holds.

Several frontier models are released below 16-bit, so their full precision is the format their makers published: Kimi K2.5 ships native INT4 weights and DeepSeek V4 Pro mixes FP4 experts with mostly FP8 other weights.

See Wick Ultra

From $656,000Includes delivery, the outdoor unit and the first year of service.

What each model was released in

The released checkpoint is the reference for quality. Converting it up to 16-bit adds memory without adding accuracy; converting it down is a separate quantization step.

Released precision and 16-bit weight memory
ModelParametersReleased as16-bit weightsSmallest Wick at 16-bit
Qwen3.5 397B397 billionBF16 configuration; official FP8 variant available794 GBWick Ultra
GLM-5744 billionBF16 configuration; official FP8 variant available1,488 GBWick Cluster node
DeepSeek V4 Pro1.6 trillionMixed FP4 expert weights and mostly FP8 other weights3,200 GBMore than one Cluster node
Kimi K2.51 trillionNative INT4 weight quantization, as in Kimi K2 Thinking2,000 GBWick Cluster node
Kimi K32.8 trillionNative MXFP4 weights with MXFP8 activations5,600 GBMore than one Cluster node

BF16, FP8 and 4-bit

BF16 and FP16 store each weight in 2 bytes, FP8 and INT8 in 1 byte, and FP4, INT4 and MXFP4 in half a byte, plus small scale factors. Each step down halves the weight memory.

NVIDIA's Rubin GPU has hardware for NVFP4, a 4-bit format: NVIDIA rates it at 50 petaflops for inference per GPU (sparse) and 35 for training (dense). Those are NVIDIA's specifications, not Wick measurements.

GPU memory in each Wick

16-bit capacity is GPU memory divided by two bytes per parameter, before context.

Weights each Wick holds, by precision
SystemGPU memory16-bit up to8-bit up to4-bit up to
Wick288 GBAbout 144 billionAbout 288 billionAbout 576 billion
Wick Pro576 GBAbout 288 billionAbout 576 billionAbout 1.15 trillion
Wick Ultra1,152 GBAbout 576 billionAbout 1.152 trillionAbout 2.3 trillion
Wick Cluster node2,304 GBAbout 1.152 trillionAbout 2.304 trillionAbout 4.6 trillion

Questions

How much VRAM does a model need in BF16?

About 2 GB per billion parameters for the weights: 1,488 GB for GLM-5's 744 billion, and more for context. GLM-5 in BF16 fits one Wick Cluster node's 2,304 GB, and its official FP8 release, 744 GB, fits Wick Ultra.

Can DeepSeek V4 Pro run at full precision on one machine?

Its released mixed FP4 and FP8 checkpoint is its full precision. The uniform 4-bit floor is 800 GB, within Wick Ultra's 1,152 GB; the released checkpoint needs somewhat more, which Wick confirms for your Wick in your build review.

BF16 or FP8: which should a team serve?

Where a maker publishes an official FP8 release, as Qwen and GLM do, serving it halves the memory against BF16. Keep BF16 where you fine-tune or need the reference outputs.

Sources

  1. Qwen3.5 397B model card on Hugging Face, observed October 27, 2026
  2. GLM-5 model card on Hugging Face, observed October 27, 2026
  3. DeepSeek V4 Pro model card on Hugging Face, observed October 27, 2026
  4. Kimi K2.5 model card on Hugging Face, observed October 27, 2026
  5. Kimi K3 model card on Hugging Face, observed October 27, 2026
  6. NVIDIA, Vera Rubin NVL72 specifications, per Rubin GPU, observed October 23, 2026

Wick figures are read from its published specifications and list prices. Checked October 27, 2026.