Running BitNet b1.58 inside DRAM by breaking DDR4 timing rules
I have been working on running BitNet b1.58 inside DRAM by intentionally breaking DDR4 timing rules. Also made a visual explainer: https://pcdeni.github.io/CaSA/explainer/ This is tested and works inside commercial off the shelf memory with custom memory controller in the FPGA. The underlying effect is well characterized in academic papers (cmu safari, simra, dram bender, etc). In the process of getting this to work I also made previously undocumented discovery about DDR behaviour: https://pcdeni.github.io/CaSA/explainer/xor-spread.html…
What it does
In the maker’s words, at launch
I have been working on running BitNet b1.58 inside DRAM by intentionally breaking DDR4 timing rules. Also made a visual explainer: https://pcdeni.github.io/CaSA/explainer/ This is tested and works inside commercial off the shelf memory with custom memory controller in the FPGA. The underlying effect is well characterized in academic papers (cmu safari, simra, dram bender, etc). In the process of getting this to work I also made previously undocumented discovery about DDR behaviour: https://pcdeni.github.io/CaSA/explainer/xor-spread.html Overall it is a bit slow, since data (in full rows) needs to be moved even when what is actually needed is only the count of the '1' bits (popcount). To make it competitive memory die changes would be needed, but not as drastic as merging compute and memory into one silicon. This would then avoid the memory wall issue the industry is currently facing.
Does the same job
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More dev tools this month
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Open-source GTM skills for technical founders
Dev tools · 29d ago · gtmcofounder.com
OpenTrailPaper is open-source bike computer firmware for the LilyGO T5S3 4.7" E-Paper PRO. It supports offline maps, GPX routes, FIT recording and Bluetooth sensors.
Dev tools · 2d ago · opentrailpaper.com
Launched alongside, May 2026
the whole month →
Parallel agents, diff reviewer, and multi-model comparisons
Dev tools · May 2026 · kilo.ai
- NW
Hey HN, Henry here from Cactus. We open-sourced Needle, a 26M parameter function-calling (tool use) model. It runs at 6000 tok/s prefill and 1200 tok/s decode on consumer devices. We were always frustrated by the little effort made towards building agentic models that run on budget phones, so we conducted investigations that led to an observation: agentic experiences are built upon tool calling, and massive models are overkill for it. Tool calling is fundamentally retrieval-and-assembly (match query to tool name, extract argument values, emit JSON), not reasoning. Cross-attention…
Life & fun · May 2026 · github.com
- FM
Dev tools · May 2026 · github.com