llmrun
XHTokenSpark2_5ForCausalLM

Spark X2.5 1.7B Base — Hardware Requirements & GPU Compatibility

Chat

Spark X2.5 1.7B Base is a 1.7B-parameter open language model from XHToken. It supports a context window of up to 1,048,576 tokens. At BF16 it needs about 3.83 GB of VRAM — see which GPUs and Macs can run it below.

1.7B params · dense1049K contextApache 2.0333 downloads17 likes51 quant downloads
S

Runs great on a 24 GB GPU

Runs from8 GB BF16 · 64KBest on24 GB BF16 · ~171 tok/s · 256KMacs from8 GB BF16 · ~19 tok/s

Apache 2.0

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run Spark X2.5 1.7B Base

One recommended way. Every other method, OS and quant is in the step-by-step guide.

Recommended

vLLM
one command · needs vLLM installed
$vllm serve XHToken/Spark-X2.5-1.7B-Base --max-model-len 16384

vLLM repo with its own quantisation

Download: Weights on Hugging Face

install, OS, other quants

Other ways

each opens step-by-step

Run in cloud

Fits on RTX 3060 12GB (7 GB headroom) · BF16

Generation speed
~61 tok/s
generation speed
Cost per 1M output tokens
$0.34
per 1M output tokens

How Much VRAM Does Spark X2.5 1.7B Base Need?

Select a quantization level; the listed hardware adheres to it.

QuantizationVRAM+32KOn RTX 4090 (reference)
3.8 GB5.6 GB16-bit · bfloat — Brain floating point 16 — preferred for trainingFits: 256K context · ~171 tok/s
est.calculated, no published file yet

Selected BF16

Brain floating point 16

4.7GBat 16K context

Weights
3.4 GB
KV cache
0.9 GB
Overhead
0.3 GB

Fits RTX 4090 (reference) · 19.4 GB free · ~171 tok/s

≥50 tok/s needs ≥294 GB/s · RTX 5090 ~304, RTX 3090 Ti ~171

Which Hardware Can Run Spark X2.5 1.7B Base?

BF16 · 3.8 GB

Spark X2.5 1.7B Base (BF16) requires 3.8 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 5+ GB is recommended. Using the full 1049K context window can add up to 60.0 GB, bringing total usage to 63.8 GB. 52 GPUs can run it, including NVIDIA GeForce RTX 5090, NVIDIA GeForce RTX 3090 Ti. 163 devices with unified memory can run Spark X2.5 1.7B Base, including Mac Studio (M3 Ultra, 256GB), Mac Studio (M3 Ultra, 512GB), MacBook Air 13" M3 (8 GB).

By VRAM tier · typical GPUs and Macs at BF16
8 GB · RTX 4060BF16 · 4.7 GB · ~46 tok/s · 64K8 GB tier →
12 GB · RTX 3060 12GBBF16 · 4.7 GB · ~61 tok/s · 128K12 GB tier →
16 GB · RTX 5060 Ti 16GBBF16 · 4.7 GB · ~76 tok/s · 128K16 GB tier →
24 GB · RTX 4090referenceBF16 · 4.7 GB · ~171 tok/s · 256K24 GB tier →
Mac 32 GB · Mac Mini M4BF16 · 4.7 GB · ~22 tok/s · 256KMacs →
Mac 64 GB · Mac Studio M4 MaxBF16 · 4.7 GB · ~100 tok/s · 512KMacs →

Alternatives to Spark X2.5 1.7B Base

Similar models

6
ModelScoreVRAMtok/sWhy it is similar
Granite 4.0 1BIBM—2.6 GB~452same size
LFM2 VL 1.6BLiquid AI—1.5 GB~496same size
Qwen 1 8BAlibaba—1.9 GB~542same size
Qwen3 1.7B BaseAlibaba—3.2 GB~417same size
DeepSeek R1 Distill Qwen 1.5BDeepSeek—1.8 GB~461same size
SmolLM2 1.7B InstructHugging Face—2.9 GB~379same size
Fine-tunes & variants(1)

Specifications

Publisher
XHToken
Parameters
1.7B
Architecture
Spark2_5ForCausalLM
Context Length
1,048,576 tokens
Vocabulary Size
131,072
Release Date
2026-08-28
License
Apache 2.0

Frequently Asked Questions

How much VRAM does Spark X2.5 1.7B Base need?

Spark X2.5 1.7B Base requires 3.8 GB of VRAM at BF16. Full 1049K context adds up to 60.0 GB (63.8 GB total).

VRAM = Weights + KV Cache + Overhead

Weights = 1.7B × 16 bits ÷ 8 = 3.4 GB

KV Cache + Overhead ≈ 0.4 GB (at 2K context + ~0.3 GB framework)

Fit ratings and hardware model lists check this model with room for a 16K-token context, which needs a little more memory.

KV Cache + Overhead ≈ 60.4 GB (at full 1049K context)

VRAM usage by quantization

3.8 GB
63.8 GB

Learn more about VRAM estimation →

Can I run Spark X2.5 1.7B Base on a Mac?

Yes — MacBook Air 13" M3 (8 GB) and 145 other Macs can run Spark X2.5 1.7B Base. Apple Silicon uses unified memory, so the model shares RAM with the system. At BF16 you need at least 3.8 GB of usable unified memory (RAM minus macOS overhead).

Can I run Spark X2.5 1.7B Base locally?

Yes — Spark X2.5 1.7B Base can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is Spark X2.5 1.7B Base?

At BF16, Spark X2.5 1.7B Base can reach ~1253 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~171 tok/s. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.

tok/s = (bandwidth GB/s ÷ model GB) × efficiency

Example: NVIDIA B200 → 8000 ÷ 3.83 × 0.65 = ~1358 tok/s

Estimated speed at BF16 (3.8 GB)

~1358 tok/s
~171 tok/s
~1358 tok/s
~1253 tok/s

Real-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.

Learn more about tok/s estimation →

What's the download size of Spark X2.5 1.7B Base?

At BF16, the download is about 3.42 GB.

Which GPUs can run Spark X2.5 1.7B Base?

52 consumer GPUs can run Spark X2.5 1.7B Base at BF16. Top options include AMD Radeon RX 6700 XT, AMD Radeon RX 6800, AMD Radeon RX 6800 XT. 52 GPUs have plenty of headroom for comfortable inference.

Which devices can run Spark X2.5 1.7B Base?

163 devices with unified memory can run Spark X2.5 1.7B Base at BF16 (3.8 GB), including AMD Ryzen AI 9 HX 370 (Strix Point) Laptop, ASUS Ascent GX10, Beelink GTR9 Pro (Ryzen AI Max+ 395, 128 GB), Framework Desktop (Ryzen AI Max+ 395, 128 GB). Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.