Depei Li

13 posts

Depei Li

Depei Li

@DepeiLi

Coding RL Bigrun & RL Science @xAI | prev @ Five Rings @JaneStreetGroup @Caltech

Katılım Aralık 2022
123 Takip Edilen221 Takipçiler
Sabitlenmiş Tweet
Depei Li
Depei Li@DepeiLi·
Grok 4.5 is out! 🚀 I spent the past few months as part of the Coding RL Bigrun and RL Science team, pushing RL scaling to help deliver Grok 4.5. Proud to have contributed to this model, working on core RL algorithm changes and executing bigruns at true frontier scale with the team. Huge shoutout to everyone at @SpaceXAI who helped make this happen!
Artificial Analysis@ArtificialAnlys

SpaceXAI’s Grok 4.5 scores 54 to place fourth on the Artificial Analysis Intelligence Index following only Fable 5, GPT-5.5, and Opus 4.8. It scores on par with GPT-5.5 in Codex on the Artificial Analysis Coding Agent Index in the Grok Build harness, at much lower cost Grok 4.5 improves 16 points over Grok 4.3 on the Intelligence Index, bringing SpaceXAI to the intelligence frontier behind only OpenAI and Anthropic, and outperforming all open weights models and notably Google’s Gemini models. Key standout areas of performance are agentic knowledge work and coding. Grok 4.5 in Grok Build scores 76 on the Artificial Analysis Coding Agent Index, on par with GPT-5.5 (xhigh) in Codex and just below Fable 5 (max) in Claude Code, and at a small fraction of the token usage and price. Congratulations to @SpaceXAI, @cursor_ai, and @elonmusk on the impressive release! Key Takeaways: ➤ Grok 4.5 performs very strongly on agentic tasks. Grok 4.5 ranks #4 on GDPval-AA v2 with an Elo of 1543, between Claude Opus 4.8 (1600) and GLM-5.2 (1513). It achieves the top score on 𝜏³-Banking of 33%, above 31% from GPT-5.5 (xhigh), and sits on the cost vs performance Pareto frontier across all three agentic evaluations in the Intelligence Index ➤ Grok 4.5 is one of the most cost efficient models to run for near-frontier intelligence. It costs $0.31 per task on the Artificial Analysis Intelligence Index and $2.59 per task on the Artificial Analysis Coding Agent Index within Grok Build ➤ Low cost for Grok 4.5 is driven by both low pricing and token efficiency. Grok 4.5 has a headline price over 60% lower than Claude Opus 4.8 and GPT-5.5, and used ~14k output tokens per Intelligence Index Task - over 60% lower than Opus 4.8. On the Coding Agent Index, Grok 4.5 stands out on the Pareto frontier of Coding Agent Index score vs. Total Tokens, using only 1.9M tokens for the Coding Agent Index while scoring 76 ➤ As a coding agent, Grok 4.5 in Grok Build is on par with GPT-5.5 and offers efficiency benefits: In our Artificial Intelligence Coding Agent Index that consists of DeepSWE, Terminal-Bench v2, and SWE-Atlas QnA, Grok 4.5 in Grok Build ranks third, on par with GPT-5.5 (Codex) and below Fable 5 (Claude Code). It is also very efficient in achieving this result: Grok 4.5 in Grok Build cost $2.49 per task while Fable 5 in Claude Code cost $11.80 and GPT-5.5 in Codex $5.07. This is driven by relatively low token pricing and the model using far fewer tokens than comparable models (1.9M average tokens used per task), significantly less than Fable 5 in Claude Code (7.2M) and GPT-5.5 in Codex (6.2M) Other model details: ➤ Context window of 500k tokens - a reduction from Grok 4.3’s 1M token context, but retaining configurable reasoning and vision input ➤ Pricing of $2/$6 per 1M tokens of input/output; cache hits are discounted by 75% to $0.5 per 1M tokens, and costs still double with long (>200k token) inputs ➤ As Elon Musk has disclosed, Grok 4.5 is 3x larger than its predecessor at 1.5T parameters

English
7
9
117
7.4K
Shen Zheng
Shen Zheng@shen_zheng25741·
Today is my last day at xAI. My time at xAI has been intense and incredibly fruitful. I had the chance to work on many interesting things, from improving Grok’s search and DeepResearch capabilities to working on longer-horizon and more autonomous ML research. It was especially rewarding to see some of that work translate not only into strong results, but also into a better experience for people using Grok every day. I’m incredibly grateful to all the friends and teammates I met along the way. I learned so much from this exceptionally talented group of people, and I have no doubt that xAI will keep getting better from here.
English
52
6
559
62.5K
Depei Li retweetledi
Deyuan Li
Deyuan Li@deyuanli8·
Try out Grok 4.5! Grok 4.5 feels both highly intelligent and token-efficient: frontier-level coding, stronger long-horizon reasoning, and more reliable agentic behavior without feeling slow. It’s been amazing to work on scaling coding RL and see it translate into real model improvements with the @SpaceXAI team.
Artificial Analysis@ArtificialAnlys

SpaceXAI’s Grok 4.5 scores 54 to place fourth on the Artificial Analysis Intelligence Index following only Fable 5, GPT-5.5, and Opus 4.8. It scores on par with GPT-5.5 in Codex on the Artificial Analysis Coding Agent Index in the Grok Build harness, at much lower cost Grok 4.5 improves 16 points over Grok 4.3 on the Intelligence Index, bringing SpaceXAI to the intelligence frontier behind only OpenAI and Anthropic, and outperforming all open weights models and notably Google’s Gemini models. Key standout areas of performance are agentic knowledge work and coding. Grok 4.5 in Grok Build scores 76 on the Artificial Analysis Coding Agent Index, on par with GPT-5.5 (xhigh) in Codex and just below Fable 5 (max) in Claude Code, and at a small fraction of the token usage and price. Congratulations to @SpaceXAI, @cursor_ai, and @elonmusk on the impressive release! Key Takeaways: ➤ Grok 4.5 performs very strongly on agentic tasks. Grok 4.5 ranks #4 on GDPval-AA v2 with an Elo of 1543, between Claude Opus 4.8 (1600) and GLM-5.2 (1513). It achieves the top score on 𝜏³-Banking of 33%, above 31% from GPT-5.5 (xhigh), and sits on the cost vs performance Pareto frontier across all three agentic evaluations in the Intelligence Index ➤ Grok 4.5 is one of the most cost efficient models to run for near-frontier intelligence. It costs $0.31 per task on the Artificial Analysis Intelligence Index and $2.59 per task on the Artificial Analysis Coding Agent Index within Grok Build ➤ Low cost for Grok 4.5 is driven by both low pricing and token efficiency. Grok 4.5 has a headline price over 60% lower than Claude Opus 4.8 and GPT-5.5, and used ~14k output tokens per Intelligence Index Task - over 60% lower than Opus 4.8. On the Coding Agent Index, Grok 4.5 stands out on the Pareto frontier of Coding Agent Index score vs. Total Tokens, using only 1.9M tokens for the Coding Agent Index while scoring 76 ➤ As a coding agent, Grok 4.5 in Grok Build is on par with GPT-5.5 and offers efficiency benefits: In our Artificial Intelligence Coding Agent Index that consists of DeepSWE, Terminal-Bench v2, and SWE-Atlas QnA, Grok 4.5 in Grok Build ranks third, on par with GPT-5.5 (Codex) and below Fable 5 (Claude Code). It is also very efficient in achieving this result: Grok 4.5 in Grok Build cost $2.49 per task while Fable 5 in Claude Code cost $11.80 and GPT-5.5 in Codex $5.07. This is driven by relatively low token pricing and the model using far fewer tokens than comparable models (1.9M average tokens used per task), significantly less than Fable 5 in Claude Code (7.2M) and GPT-5.5 in Codex (6.2M) Other model details: ➤ Context window of 500k tokens - a reduction from Grok 4.3’s 1M token context, but retaining configurable reasoning and vision input ➤ Pricing of $2/$6 per 1M tokens of input/output; cache hits are discounted by 75% to $0.5 per 1M tokens, and costs still double with long (>200k token) inputs ➤ As Elon Musk has disclosed, Grok 4.5 is 3x larger than its predecessor at 1.5T parameters

English
3
5
73
3.4K
Depei Li retweetledi
Hanqing Zhu
Hanqing Zhu@zhu_hanqin41424·
Excited to help bring Grok 4.5 to life 🚀 Fast, capable, and a huge leap for us. Over the past few months, our small team pushed RL scaling to the next level and reached top-tier agentic coding performance. This one was all-in for me: driving core algorithmic changes across RL stability and intelligence per token, while spending many long days and nights in the bigrun loop with my amazing xAI colleagues. Many doubted us, but the incredible people at @SpaceXAI made it happen. More to come 😎
SpaceXAI@SpaceXAI

Announcing Grok 4.5, our first model trained specifically for coding and agents. It was trained with Cursor and offers frontier intelligence at leading speeds and cost efficiency. x.ai/news/grok-4-5

English
20
13
226
14K
Depei Li retweetledi
Dinghuai Zhang 张鼎怀
Excited to deliver Grok 4.5, with which we pushed RL scaling to the next level and achieve top-tier agentic coding performance. The past few months have been intense for me — driving fundamental algorithmic changes on both RL stability and capability, iterating days and nights on RL infra, and executing bigruns at true frontier scale. Even a few months ago, I would not have believed this was possible with such a small team under such difficult situation. Shoutout to all colleagues at xAI! 🫡
SpaceXAI@SpaceXAI

Announcing Grok 4.5, our first model trained specifically for coding and agents. It was trained with Cursor and offers frontier intelligence at leading speeds and cost efficiency. x.ai/news/grok-4-5

English
82
64
1.5K
187.5K
Tianyi Zhang
Tianyi Zhang@mycharmspace·
Today is my last day at xAI. I joined xAI a year ago and had the pleasure of leading the search and factuality post-training team. Over time, we developed so many recipe and engineering co-optimizations, making Grok the best AI for search and real-time agent. I am also particularly proud of working with a small group of talented people delivering the recent iterations of the instant mode of Grok - the one I personally liked and used the most. My thanks to all the friends and teammates for their support and help over the past year. They are among the brightest minds I’ve met in my career. I am sure the team will continue the mission to make better Grok and understand the universe.
English
84
9
648
84.8K
Honghua Zhang
Honghua Zhang@HonghuaZhang2·
It’s really been a great pleasure.
English
23
0
47
5.6K
Arshdeep Singh
Arshdeep Singh@arshdeep·
After an unforgettable ride, this was my last week at @xai. When I joined in 2024, xAI was a small yet an extraordinary team. I got an amazing opportunity to build our core ML Platforms from scratch and form an ambitious, amazing team. Together we built the core systems that power frontier-model research, evaluations, human data collection, agent training, and daily productivity for every member of technical staff at xAI. It was a true privilege. I’m deeply grateful to @elonmusk and every single person I’ve had the chance to work with across research, engineering, compute, infra, and beyond. The pace, collaboration, and shared mission to understand the universe and be truth seeking have been unmatched. Being able to contribute to data, training, and infra behind Grok-2-1212, Grok 3, Grok 4, 4.2, Aurora, Imagine and many other efforts been the highlight of my career so far. Special thank you to my incredible team and all the brilliant people who made this ride so special. I leave more inspired than ever. Excited for what’s next. Ad astra 🚀
Arshdeep Singh tweet mediaArshdeep Singh tweet media
English
89
16
852
83.5K