Skip to content

Commit 8b5d7bf

Browse files
neon60j-stephan
andauthored
Update FAQ: Add system optimization page link and some new questions (#3605)
## Motivation Cover the following issue: #2991 ## Technical Details Add system optimization page link and some new questions about the Strix Halo linux compatibility. ## Test Plan ## Test Result ## Submission Checklist - [x] Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests. --------- Co-authored-by: Jan Stephan <Jan.Stephan@amd.com>
1 parent 6280066 commit 8b5d7bf

1 file changed

Lines changed: 37 additions & 19 deletions

File tree

docs/faq.md

Lines changed: 37 additions & 19 deletions
Original file line numberDiff line numberDiff line change
@@ -32,8 +32,25 @@ and release history, please refer to the the [SUPPORTED_GPUs](https://github.com
3232
list, and the [RELEASES](https://github.com/ROCm/TheRock/blob/main/RELEASES.md)
3333
file.
3434

35+
For hardware-specific notes and tuning guidance, see the [System optimization pages](https://rocm.docs.amd.com/en/latest/how-to/system-optimization/index.html)
36+
3537
## gfx1151 (Strix Halo) specific questions
3638

39+
Strix Halo specific notes and optimization guidance information are collected on
40+
the [Strix Halo system optimization page](https://rocm.docs.amd.com/en/latest/how-to/system-optimization/strixhalo.html).
41+
42+
### Which OS are supported for Strix Halo?
43+
44+
The most current list of compatible GPU architectures is available on the
45+
[SUPPORTED_GPUs](https://github.com/ROCm/TheRock/blob/main/SUPPORTED_GPUS.md)
46+
page.
47+
48+
For Linux systems running kernel versions earlier than 6.18.4, Strix Halo
49+
requires an additional kernel patch to operate properly. For complete details
50+
on Linux kernel compatibility and required configurations, refer to the system
51+
optimization guide:
52+
https://rocm.docs.amd.com/en/latest/how-to/system-optimization/strixhalo.html#required-kernel-version
53+
3754
### Why does PyTorch use Graphics Translation Table (GTT) instead of VRAM on gfx1151?
3855

3956
On Strix Halo GPUs (gfx1151) memory access is handled through GPU Virtual Memory
@@ -56,29 +73,30 @@ discrete VRAM. Instead:
5673
AI workloads typically prefer GTT-backed allocations because they allow large,
5774
flexible mappings without permanently reserving memory for GPU-only use.
5875

59-
For practical implementation details on virtual memory management APIs, see the
60-
[HIP Virtual Memory Management documentation](https://rocm.docs.amd.com/projects/HIP/en/latest/how-to/hip_runtime_api/memory_management/virtual_memory.html).
76+
For more information, see the
77+
[Strix Halo system optimization page – Memory settings](https://rocm.docs.amd.com/en/latest/how-to/system-optimization/strixhalo.html#memory-settings)
6178

6279
### What is the difference between Graphics Address Remapping Table (GART) and GTT?
6380

6481
Within GPUVM, two commonly referenced limits exist:
6582

66-
- GART defines the amount of platform address space (system RAM or Memory-Mapped
67-
I/O) that can be mapped into the GPU virtual address space used by the kernel
68-
driver. It is typically kept relatively small to limit GPU page-table size and
69-
is mainly used for driver-internal operations.
70-
71-
- GTT defines the amount of platform address space (system RAM) that can be
72-
mapped into the GPU virtual address spaces used by user processes. This is the
73-
memory pool visible to applications such as PyTorch and other AI workloads.
83+
- GART (Graphics Address Remapping Table): Defines the amount of platform
84+
address space (system RAM or Memory-Mapped I/O) that can be mapped into the
85+
GPU virtual address space used by the kernel driver. On systems with
86+
physically shared CPU and GPU memory, such as Strix Halo, this mapped system
87+
memory effectively serves as VRAM for the GPU. GART is typically kept
88+
relatively small to limit GPU page-table size and is mainly used for
89+
driver-internal operations.
7490

75-
### Why is allocating to GTT beneficial compared to VRAM?
91+
- GTT (Graphics Translation Table): Defines the amount of system RAM that can be
92+
mapped into GPU virtual address spaces for user processes. This is the memory
93+
pool used by applications such as PyTorch and other AI/compute workloads.
94+
GTT allocations are dynamic and are not permanently reserved, allowing the
95+
operating system to reclaim memory when it is not actively used by the GPU.
96+
By default, the GTT limit is set to approximately 50% of total system RAM.
7697

77-
Allocating large amounts of VRAM permanently removes that memory from general
78-
system use. Increasing GTT allows memory to remain available to both the
79-
operating system and the GPU as needed, providing better flexibility for mixed
80-
workloads. This behavior is expected and intentional on unified memory
81-
architectures.
98+
For more information, see the
99+
[Strix Halo system optimization page – Memory settings](https://rocm.docs.amd.com/en/latest/how-to/system-optimization/strixhalo.html#memory-settings)
82100

83101
### Can I prioritize VRAM usage over GTT?
84102

@@ -96,9 +114,9 @@ For information on configuring GTT size, see the next question.
96114

97115
### How do I configure shared memory allocation on Linux?
98116

99-
For GPUs using unified memory (including gfx1151/Strix Halo APUs), you can adjust
100-
the Graphics Translation Table (GTT) size allocation. See the official ROCm
101-
documentation on [configuring shared memory](https://rocm.docs.amd.com/projects/radeon-ryzen/en/latest/docs/install/installryz/native_linux/install-ryzen.html#configure-shared-memory).
117+
For GPUs using unified memory (including gfx1151/Strix Halo APUs), you can
118+
adjust the GTT size allocation. See the official ROCm documentation on
119+
[configuring shared memory](https://rocm.docs.amd.com/en/latest/how-to/system-optimization/strixhalo.html#configuring-shared-memory-limits-on-linux).
102120

103121
Note: This applies to Linux systems only and is relevant for any GPU using shared
104122
memory, not just Strix Halo.

0 commit comments

Comments
 (0)