Compare/DeepSeek V4 Flash (Non-reasoning) vs Step 3.5 Flash 2603

DeepSeek V4 Flash (Non-reasoning)vsStep 3.5 Flash 2603

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

DeepSeek

DeepSeek V4 Flash (Non-reasoning)

Input
$0.14/M
Output
$0.28/M
Speed
111 tok/s
TTFT
0.89s
StepFun

Step 3.5 Flash 2603

Input
$0.1/M
Output
$0.3/M
Speed
180 tok/s
TTFT
0.92s

Winner by Category

Cheaper
Step 3.5 Flash 2603
Faster (tok/s)
Step 3.5 Flash 2603
Lower Latency
DeepSeek V4 Flash (Non-reasoning)
Benchmarks (2-4)
Step 3.5 Flash 2603

Pricing Comparison

MetricDeepSeek V4 Flash (Non-reasoning)Step 3.5 Flash 2603
Input ($/M tokens)$0.14$0.1
Output ($/M tokens)$0.28$0.3
Cost for 1M input + 100K output tokens:
DeepSeek V4 Flash (Non-reasoning)$0.17
Step 3.5 Flash 2603$0.13

Speed Comparison

Output Speed (tokens/s) — higher is better
DeepSeek V4 Flash (Non-reasoning)
111 tok/s
Step 3.5 Flash 2603
180 tok/s
Time to First Token (seconds) — lower is better
DeepSeek V4 Flash (Non-reasoning)
0.89s
Step 3.5 Flash 2603
0.92s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
28.726.0
Coding Index
Math Index
GPQA Diamond
71.6%82.6%
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
7.0%22.6%
SciCode
37.3%38.5%
IFBench
47.2%66.5%
TerminalBench
34.1%32.6%
DeepSeek V4 Flash (Non-reasoning)2 wins
4 winsStep 3.5 Flash 2603

Frequently Asked Questions

Which is cheaper, DeepSeek V4 Flash (Non-reasoning) or Step 3.5 Flash 2603?

Step 3.5 Flash 2603 is cheaper overall. Its blended price (3:1 input/output ratio) is $0.15/M tokens vs $0.17/M for DeepSeek V4 Flash (Non-reasoning).

Which model performs better on benchmarks?

Step 3.5 Flash 2603 wins 4 out of 12 benchmarks compared to 2 for DeepSeek V4 Flash (Non-reasoning). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

Step 3.5 Flash 2603 generates tokens faster at 180 tok/s vs 111 tok/s. DeepSeek V4 Flash (Non-reasoning) also has lower time-to-first-token (0.89s vs 0.92s).

When should I use DeepSeek V4 Flash (Non-reasoning) vs Step 3.5 Flash 2603?

Choose based on your priorities: Step 3.5 Flash 2603 for lower cost, Step 3.5 Flash 2603 for stronger benchmark performance, and Step 3.5 Flash 2603 for faster generation. For latency-sensitive apps, check the TTFT comparison above.