Files
LocalAI/pkg/xsysinfo/minvram_internal_test.go
LocalAI [bot] 0d6de15ae9 fix(config): per-device VRAM headroom for Blackwell defaults (#10485) (#10494)
The hardware-tuned defaults from #10411 were measured on a GB10 / DGX Spark
(128 GiB unified memory) and over-provisioned multi-GPU consumer Blackwell
(e.g. 2x16 GiB RTX 50-series) into CUDA OOM during model init:

  - The Blackwell physical batch (512 -> 2048) sets both n_batch and n_ubatch.
    The compute buffer scales ~n_ubatch * n_ctx and is allocated PER DEVICE
    (it can't be split across GPUs), so a large context turns ub2048 into
    multi-GiB of scratch that must fit one 16 GiB card.
  - The VRAM-scaled parallel-slot default tiered off TotalAvailableVRAM(),
    which SUMS all GPUs (2x16 -> "32 GiB" -> 8 slots), but the allocations
    are per-device.

Make both decisions per-device and context-aware:

  - xsysinfo.MinPerGPUVRAM() reports the smallest device's VRAM; localGPU()
    uses it so the parallel tier and batch guard reason about one card.
  - PhysicalBatchForContext(gpu, ctx) raises the batch only when the extra
    compute buffer fits VRAM/4 at this model's context (16 GiB crosses over
    ~174k ctx, 32 GiB ~349k; GB10 reports system RAM so it still clears it).
  - Apply hardware defaults AFTER runBackendHooks in SetDefaults so the
    GGUF-guessed context is resolved before the batch decision.
  - The distributed router gates the node batch the same way.

Unified-memory devices (GB10, Apple) report system RAM as their single
device's VRAM, so they keep the prefill win.


Assisted-by: Claude:opus-4.8 [Claude Code]

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
2026-06-25 00:07:48 +02:00

38 lines
1.0 KiB
Go

package xsysinfo
import (
. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
)
var _ = Describe("minNonZeroVRAM", func() {
const gib = uint64(1) << 30
It("returns the smallest device on a multi-GPU host", func() {
// Two unequal cards (e.g. RTX 5070 Ti + 5060 Ti, both 16 GiB, or a
// mixed pair): the smallest device is the per-card allocation ceiling.
infos := []GPUMemoryInfo{
{TotalVRAM: 16 * gib},
{TotalVRAM: 12 * gib},
}
Expect(minNonZeroVRAM(infos)).To(Equal(12 * gib))
})
It("ignores devices that report zero VRAM", func() {
infos := []GPUMemoryInfo{
{TotalVRAM: 0},
{TotalVRAM: 24 * gib},
}
Expect(minNonZeroVRAM(infos)).To(Equal(24 * gib))
})
It("returns the single device's VRAM on a one-GPU host", func() {
Expect(minNonZeroVRAM([]GPUMemoryInfo{{TotalVRAM: 16 * gib}})).To(Equal(16 * gib))
})
It("returns 0 when no device reports VRAM", func() {
Expect(minNonZeroVRAM([]GPUMemoryInfo{{TotalVRAM: 0}})).To(BeZero())
Expect(minNonZeroVRAM(nil)).To(BeZero())
})
})