> ## Documentation Index
> Fetch the complete documentation index at: https://sambanova-systems.mintlify.site/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# SambaNova Runtime release notes

Release notes for SambaNova Runtime, including new features, enhancements, and fixes.

<Note>
  For release notes older than those listed here, see the [Runtime release notes archive](https://docs-legacy.sambanova.ai/runtime/latest/runtime-release-notes.html).
</Note>

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## SambaNova Runtime v1.26.1-2 release

**Release Date:** May 1, 2026

This release includes runtime performance improvements, expanded hardware support for 4-channel DDR configurations, larger model bundle support, automated SNFM database migration, and fan fault detection.

### New features and enhancements

**Argins performance improvements for TTFT, throughput, and model switching**

Reduces TTFT, token throughput, and model switching latency through three runtime optimizations:

* Argin table structures are precomputed at model load time rather than recomputed per request
* Schedule updates run in parallel per RDU
* Argument tables use contiguous memory allocation to reduce DMA operations

**Per-section AGCU/SLB tracking for larger model bundles**

Enables larger model bundles, including Llama 4 Maverick, by tracking AGCU and SLB resource usage per section rather than per segment, allowing accurate resource allocation when loading models into memory.

**Pipelined AGCU control commands**

Two separate graph control commands such as PL and AL+EXEC can now be launched together instead of sequentially, reducing CSR write time. Use `CMD_PIPELINE_OPT=0` to disable the feature (enabled by default).

**SNFM DB migration during SND initialization**

SNFM automatically migrates the error and fault history databases during SND initialization when the `sambanova-runtime` package is installed or upgraded. Error and fault history is preserved across runtime version upgrades that change the database schema.

**Runtime support for 4-channel DDR configurations**

Adds runtime support for SambaRack SN40L-16 nodes with 4-channel (1DPC) DDR configurations:

* Corrects DDR physical address calculation for 4-DIMM 1DPC systems
* Updates the inventory health check so RDUs with 4 DDR channels are reported as healthy in `snfadm inventory` rather than degraded

**Fan fault detection and reporting**

Runtime now detects and reports fan speed critical faults forwarded from system firmware. Fan faults are surfaced as `ETYPE_FAN_SPEED_CRIT` in `snfadm` error logs, enabling faster identification of thermal and cooling issues that could affect system stability.

**Optimized checkpoint loading with AVX instructions**

Improved performance for checkpoint loading through optimized RM→CVRM conversions using AVX instructions.

### Changes

**Updated default Huge Page allocation**

The default Huge Page allocation has been increased from ¼ to ⅓ of physical host memory, with a maximum allocation of 512 × 1 GB pages.

* If a system has fewer Huge Pages than the new default, installing the `sambanova-runtime` package automatically increases the allocation.
* If a system has more Huge Pages than the new default and you want to apply the new default, run `/opt/sambaflow/bin/snconfig set hugepages` with no options.

### Bug fixes

* **Performance counter return values** - Fixes incorrect performance counter return values.
* **Host memory huge page fix in argtable coallocate path** - Fixes argtable collocation to correctly account for host memory huge page size.

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