Spark X2.5 1.7B
Parameters
1.7B
Context Length
1.05M
Modality
Text
Architecture
Dense
KV Cache Rate
56 KB/tok
License
Apache 2.0
Release Date
24 Aug 2026
Knowledge Cutoff
-
API Pricing (per 1M)
Self-hosted only
Hardware Sizing
Precision
Context
Workload Memory: 3.73 GB
INT4 · 8K context
Base Weights: 0.79 GB
KV Cache: 0.44 GB
Runtime & Graphs: 2.50 GB
Minimum Required Hardware
1x NVIDIA L4 24GB
3.7 / 21.6 GB usable
1x RTX 3060 12GB
3.7 / 10.8 GB usable
Apple M4 24GB
3.7 / 18.0 GB usable
Determine requirements for your specific workload:
Open in VRAM Calculator
Architecture Diagram
Evaluation Benchmarks
No evaluation benchmarks for Spark X2.5 1.7B available.
Rankings
Overall Rank
-
Coding Rank
-
About Spark X2.5 1.7B
Spark X2.5 1.7B is an ultra-lightweight open-weights model tailored for mobile and on-device text generation. It balances minimal latency and low memory footprint with solid general-domain understanding.
Technical Specifications
Attention
Attention Structure
Grouped-Query Attention
Attention Heads
8
Key-Value Heads
2
Attention Head Dimension
256
Position Embedding
ROPE
RoPE Theta
5,000,000
Sliding Window Attention
Yes
Sliding Window Size
512
Sliding Window Ratio
75.0%
Normalization
RMS Normalization
Activation Function
GELU
Dimensions
Hidden Dimension Size
2,048
Number of Layers
28
FFN Intermediate Size (Dense)
6,656
Tokenizer
Vocabulary Size
131,072
Resources
About Spark X
The Spark X model series developed by Thinking Machine Labs, featuring lightweight and high-efficiency models optimized for edge deployment, fast local inference, and low memory footprints.