Model library / XHToken
Spark-X2.5-1.7B is a 1.7 billion-parameter causal language model from XHToken with a 1 M token context window, released under Apache-2.0.
Parameters in total
Context length in tokens, as published
Weights at the released precision
Licence declared on the repository
Overview
Spark-X2.5-1.7B is a 1.7 billion-parameter causal language model released by XHToken. According to the publisher it is a compact, general-purpose model aimed at everyday tasks such as conversation, writing, translation, reasoning, coding, tool utilisation and agentic workflows, and it claims strong performance across more than 200 languages.
The model contains 1.7 billion parameters stored in bfloat16 format, which keeps the memory footprint modest for inference on GPUs or other accelerators. It offers a native context window of 1,048,576 tokens, allowing processing of very long sequences without external chunking. The weights are distributed under the Apache-2.0 licence, permitting unrestricted commercial and research use.
Specification
| Repository | XHToken/Spark-X2.5-1.7B |
| Publisher | XHToken |
| Published | 24 August 2026 |
| Architecture | Spark2_5ForCausalLM |
| Model type | spark2_5 |
| Parameters | 1,707,657,216 |
| Layers | 28 |
| Hidden size | 2,048 |
| Attention heads | 8, 2 key/value heads |
| Context length | 1,048,576 tokens |
| Vocabulary | 131,072 tokens |
| Weight format | bfloat16 |
| Licence | apache-2.0 |
| Base model | XHToken/Spark-X2.5-1.7B-Base |
Memory
Parameter count multiplied by the bytes each format uses. The key-value cache comes on top.
| Precision | Weights | Notes |
|---|---|---|
| bf16 | 3.2 GiB | Full precision as released |
| fp8 | 1.6 GiB | 8-bit, near-lossless on most models |
| int4 | 0.8 GiB | 4-bit, smallest footprint |
The cache costs 56 KiB per token at 16-bit, so the full 1,048,576-token context of one request needs about 56.0 GiB. Concurrency multiplies that number, not the weights.
That figure is an upper bound: this model uses sliding-window attention with a 512-token window on some layers, so long requests cache less than this.
Hardware
At the released precision, with 90% of the card given to the server and 2.5 GiB kept for the runtime. The context column is what is left for the cache on that setup.
| GPU | Cards needed | Free for cache | Context it holds |
|---|---|---|---|
| RTX 4090 24GB | 1 | 15.9 GiB | about 298,080 tokens |
| RTX 5090 32GB | 1 | 23.1 GiB | about 432,897 tokens |
| L40S 48GB | 1 | 37.5 GiB | about 702,531 tokens |
| A100 80GB | 1 | 66.3 GiB | the full 1,048,576 tokens |
| H100 80GB | 1 | 66.3 GiB | the full 1,048,576 tokens |
| RTX PRO 6000 96GB | 1 | 80.7 GiB | the full 1,048,576 tokens |
| H200 141GB | 1 | 121.2 GiB | the full 1,048,576 tokens |
Serving
A vLLM launch line for the shape above. Check the model card for a runtime the publisher recommends.
vllm serve XHToken/Spark-X2.5-1.7B \ --max-model-len 294912 \ --gpu-memory-utilization 0.90
Questions
The weights take about 3 GiB at the released precision. That fits on one RTX 4090 24GB, which leaves roughly 16 GiB for the key-value cache.
The repository declares apache-2.0. Read the licence text before commercial use: the name alone does not tell you what is allowed.
The configuration allows 1,048,576 tokens. Whether the whole window is usable depends on the memory left for the cache, which the hardware table works out per card.
This page is a reference, and Aiqre does not serve this model today. We deploy open-weight models on dedicated EU hardware on request, so if you want an OpenAI-compatible endpoint for it, email [email protected] with the model name and roughly what volume you expect.
Also in the library
Spark-X2.5-4B is a 4.1 billion-parameter causal language model from XHToken designed for general-purpose tasks with a 1 M token c…
Spark-X2.5-1.7B-Base is a 1.7 billion-parameter general-purpose language model with a native 1 M-token context window.
Spark-X2.5-4B is a 4.1-billion-parameter causal language model with a 1-million-token context window, released under Apache-2.0.
MiniCPM5-2B is a 2-billion-parameter dense transformer aimed at on-device and resource-constrained deployments.
Hosting
Tell us the model and roughly what volume you expect. We reply with a price and an OpenAI-compatible endpoint, with your prompts never stored.