DeepSeek V4.1 Pro vs GPT-6.1 Sol: Five Times the Output Price and Four Times the Speed

GPT-6.1 Sol costs $2.00 per million input tokens and $10.00 per million output, serves a 1M context with a 128K output ceiling, and returns its first token in 1.36 seconds — the fastest figure in any comparison on this site. DeepSeek V4 Pro costs $0.66 and $1.98 off-peak, with a 384K output ceiling and 6.22 seconds to first token. DeepSeek V4.1 Pro, the name in the title, has no card, no price and no endpoint.

So the honest matchup is Sol against DeepSeek's real flagship, and its shape is unusual: the cheaper model is four and a half times slower at the front of every request. That is the whole decision, and it costs nothing to test.

The cards

• GPT-6.1 Sol — $2.00 in, $10.00 out; 1M context; 128K maximum output; input text, image and file; 1.36 seconds to first token.

• DeepSeek V4 Pro — $0.66 in, $1.98 out off-peak; $0.022 cached; $1.32 and $3.96 during the two weekday peak windows; 1M context; 384K output; text-only; 6.22 seconds.

• DeepSeek V4.1 Pro — named once on 10 September; nothing published since.

What each card buys on a real task

One million input tokens and 100,000 output tokens. Sol: $2.00 plus $1.00 — $3.00. DeepSeek off-peak: 86 cents. In a peak window: $1.72. So the price gap is 3.5× off-peak and 1.7× in peak — smaller than the output line alone suggests, because output is only a tenth of this task's tokens.

For decoding-heavy work the ratio widens to five on the output column, and that is where Sol's premium lives. For reading-heavy work — long documents, code review, retrieval — the input line decides and the gap is modest.

Then the inverted column: 1.36 seconds against 6.22. Sol starts answering while DeepSeek is still reading, four and a half times over. In an agent loop that runs twenty turns, that is more than ninety seconds of pure waiting per task — a cost no rate card shows and every user feels.

Where the 384K ceiling changes the answer

Sol's 128K output ceiling is a third of DeepSeek's 384K. For single-call generation of a long document, the DeepSeek side does the job and Sol refuses it. That is the one workload where the slow, cheap model is also the only model, and it is worth knowing before the latency argument closes the decision.

Why V4.1 Pro is in the title and not in the table

Because there is nothing to put there. DeepSeek named the tier once, in the release note that shipped V4.1 Flash, in a sentence about routing Pro requests to Flash "until V4.1-Pro launches" — a plan withdrawn after developers objected. No card, no repository, no third price column has appeared.

The substitute used throughout is V4 Pro, labelled as such. When the tier ships, the interesting question will be whether it keeps the peak-window schedule and the 384K ceiling, because those two features — not the price — are what make this matchup interesting today.

What to run

GPT-6.1 Sol and DeepSeek V4 Pro are both on OrcaRouter at their vendors' published rates, on one OpenAI-compatible endpoint with automatic failover. The routing rule: latency-sensitive and image-bearing traffic to Sol, high-volume text generation and long single-call documents to DeepSeek off-peak.

And a note on the assumption underneath all of this: DeepSeek's peak windows are 01:00–04:00 and 06:00–10:00 UTC on weekdays. If your workload cannot be scheduled around them, the price advantage in this page halves before anything else is counted.