Cognition releases SWE-1.5, a new coding model in Windsurf, saying it partnered with Cerebras to serve SWE-1.5 at speeds up to 13x faster than Claude Sonnet 4.5
lots of new paradigms/UX to figure out. @cognition : Today we're releasing SWE-1.5, our fast agent model. It achieves near-SOTA coding performance while setting a new standard for speed. Now available in @windsurf. [image] Forums: r/windsurf : Cognition | Introducing SWE-1.5: Our Fast Agent Model
Cognition
Context & Ripple Effects
Cognition is extending the model line that began with Windsurf’s initial SWE-1 release, which positioned proprietary software-engineering models against leading general-purpose systems.
The move also puts Cognition’s acquisition of Windsurf to work: the company can pair its own coding model with a distribution surface rather than depend solely on a standalone agent product.
First-order effects
Windsurf users gain access to SWE-1.5, with Cognition claiming near-state-of-the-art coding performance and up to 13x faster serving than Claude Sonnet 4.5 through Cerebras.
Cognition and Cerebras turn inference speed into a product-level differentiator for an agentic coding workflow, not merely a backend infrastructure claim.
Second-order effects
Coding-assistant rivals face added pressure to compete on interactive latency as well as benchmark quality; faster model responses can make multi-step agent workflows feel more usable.
Cerebras gains a prominent application deployment that complements its own code-focused subscription offerings, while Windsurf becomes more tightly differentiated by Cognition-controlled model access.
Third-order effects
If these deployments persist, coding-model competition may increasingly be organized around vertically integrated combinations of model, inference runtime, and developer workspace rather than model weights alone.
The durable question is whether low-latency serving can sustain performance and economics at production demand; that will determine whether speed becomes a defensible platform advantage or a feature competitors can match.
The trend: AI coding platforms are shifting from standalone model comparisons toward integrated stacks in which inference latency, agent behavior, and workspace distribution are jointly competitive.
We designed SWE-1.5 as an integrated package: the model, inference, and agent harness are co-designed as a unified system optimized for both speed and intelligence. https://cognition.ai/... We partnered with @cerebras to serve it at up to 950 tok/s - 6x faster than Haiku 4.5 and …
“Performance on coding benchmarks is often not representative of the real-world experience of using an agent, which is why we stopped reporting SWE-Bench numbers in 2024.” https://cognition.ai/...
keep in mind: the August snapshot of Opus 4.1 scored 22.71% on SWE-Bench Pro. SWE-1.5 (13x faster than sonnet 4.5) scores ~2x higher than the SOTA code model from only 2 months ago. made possible by owning the stack: model, inference, & agent harness! agent lab era is here! [imag…
The best way to make coding agents interactive is to just make them run faster than you can think. We're already hitting internal PMF with SWE-1.5, and this is only the beginning!
We're a model company again. Coding models typically sacrifice speed over quality, which gives users a trade off when selecting which model to pick in @windsurf, but today, we release SWE-1.5, which outputs at a blistering 950 tokens per second, 13x faster than Sonnet 4.5. Not [i…
One of my personal goals at Cognition is maximizing speed in everything we do, so naturally I loved contributing to this project Excited to launch SWE-1.5, our first model designed for building incredibly fast agents - can't wait for what we're about to ship next
@ClementDelangue I just wish people would share what base model they are using! Both Cursor and Windsurf wouldn't say, I think that's a bit rude to be honest - the base model deserves credit even if the license doesn't demand it
We're finally reaching the era of everyone training their own models based on open-source (versus relying on black box generalist APIs) and it is glorious!
super excited to finally release SWE-1.5 - a frontier-scale model (~hundreds of billions of params) running at insane speeds (up to 950 tok/s) - outperforms GPT-5-High on SWE-Bench-Pro - 13x faster than Sonnet 4.5, 6x faster than Haiku 4.5 - more than double the benchmark perf
Introducing SWE-1.5, our fast agent model. It achieves near-SOTA coding performance while setting a new standard for speed. Now available in Windsurf. [image]
don't write this off as “fast, non-frontier-lab model == dumb & not worth my time” it's smarter than the SOTA models were this summer and also way faster (more chances to iterate/fix in same time, less waiting) 1 pt of reference: SWE-1.5 > GPT-5 (high) on SWE-Bench Pro! [image]
Today, @cognition released SWE-1.5 - the world's fastest coding agent, powered by Cerebras. SWE-1.5 achieves frontier-level coding ability, comparable to Sonnet 4.5 and surpassing GPT-5. Cerebras and Cognition engineers worked hand in hand over the past few weeks, training a [ima…
Try our new model! This is the first in house model to be trained on thousands of GB200s, and we had to deal with a bunch of issues due to the lack of open source support. Glad everything worked out, and we now have a frontier coding model that beats GPT-5 High and is crazily
The SWE-1.5 is the best model I have used recently. It perfectly balances coding intelligence with speed. It matches Claude Sonnet 4.5 thinking's intelligence, but is at least 10x faster. SWE-1.5 as a daily driver is too good to be true. @cognition @windsurf are cooking like
Speed is the next frontier! Very excited to be at the forefront of this; programming looks very different when agents can output code faster than you can think — lots of new paradigms/UX to figure out.
Today we're releasing SWE-1.5, our fast agent model. It achieves near-SOTA coding performance while setting a new standard for speed. Now available in @windsurf. [image]