This quarter · arXiv preprint, October 2026

SAFARI pushes HBM2 power 23.6% past JEDEC; HBM3E is untested

ETH Zürich and NYU's SAFARI group test 36 HBM2 chips and find an access pattern that draws 23.6% more power than the highest-power measurement loop in the JEDEC memory standard, averaged across the 36 chips. The abstract says: "we engineer an access pattern that yields 23.6% higher power consumption on average across 36 tested HBM2 chips than the highest-power-consuming JEDEC-specified current measurement loop" (arXiv 2610.14244). In a second comparison, toggling the bus signals of every bank group draws 29.4% more than holding them constant. The authors validated their new power model against three NVIDIA H200s, with errors of 2.4% to 5.3%. Only HBM2 was tested, not HBM3E or HBM4. The abstract doesn't say whose chips the 36 are or at what temperature and frequency they were measured, and the full paper hasn't been reviewed. Our reading: for HBM2, a deliberately designed access pattern can exceed the power of JEDEC's measurement loops. The abstract doesn't answer whether real workloads come close to that level, or whether HBM3E and HBM4 behave the same way. How we checked →

Concept illustration: on the left of a light grey table sits a large beige circuit board with thin traces and black connectors, a red chip lettered "HBM2" at its centre and a pale pink circle behind it; thin black cables run from the board to an open laptop and to a black clamp-like device below the board, which is fitted around a thick grey-brown cable running down out of the frame. On the right, a person with long dark hair, a black top, grey-brown wide trousers and white sneakers sits on a tall black stool typing on the laptop, whose screen shows grey lines, and near the top two panels sit side by side, a black one lettered "ETH ZÜRICH" and a beige one lettered "NYU".

Source and checks

This item ran in the brief of Oct 16, 2026, alongside 19 other items. How we checked it, the quote checks and what was still missing that day are on that issue's How we checked page.

Cite this item

SecondSource (2026). "SAFARI pushes HBM2 power 23.6% past JEDEC; HBM3E is untested." https://secondsource.io/en/news/2026-10-16-7/. Accessed access date.