GPU (AMD Oberon / RDNA2)

PCI ID: 1002:13fb

Status

• amdgpu loads and drives HDMI output - working
• Hardware video decode (VCN) - not working (IP block not registered)

Boost

Default GPU clock is lower than PS5 OS. Use ps5_control to unlock full speed:

cd ps5-linux-tools
sudo ./ps5_control --fan on
sudo ./ps5_control --boost on

Always enable fan alongside boost - this matches PS5 OS behavior.

To enable at boot:

sudo ./install.sh

This installs ps5fan.service and ps5boost.service as systemd units.

40 CU Unlock

PS5 units ship with either 36 or 38 active CUs out of 40 total - the remainder are harvested (disabled) in silicon. How many CUs your unit actually has is hardware-specific: some consoles physically cap at 38, some have all 40. This also means benchmark scores vary between units. The ps5-linux kernel patch unlocks whichever harvested CUs are present.

Kernel parameter: amdgpu.ps5_cu_unlock=N

Value	Behavior
0	Off (default)
1	Probe
2	Unlock SE0/SH0 only
3	Unlock all harvested CUs
4	Probe-all

Without the unlock parameter, dmesg reports the hardware-default active CU count:

amdgpu: SE 2, SH per SE 2, CU per SH 10, active_cu_number 36

(2 × 2 × 10 = 40 total physical CUs, 36 active by default on this unit)

To unlock all CUs, add to cmdline.txt on the FAT32 USB partition:

amdgpu.ps5_cu_unlock=3

The patch writes to both the CC register and SPI - both are required for the unlock to actually affect dispatch (verified on BC-250).

Source: ps5-linux-patches commit 5b0dc56

VCN / Hardware Video Decode

amdgpu for 1002:13fb does not register the vcn_v3_0 IP block. Mesa, VAAPI, and ffmpeg userspace are fine - the kernel driver simply never exposes VCN. Software decode only for now.

Known fix (not yet upstream): patch drivers/gpu/drm/amd/amdgpu/nv.c to add vcn_v3_0 for 0x13fb and rebuild the kernel. Tracked in ps5-linux-patches TODO.

VRAM

Default allocation shown in tools is 512MB, but this is dynamic - the driver escalates and allocates more as needed. With 16GB shared RAM/VRAM, the GPU can use up to ~12GB in practice.

To set a fixed allocation, edit vram.txt on the FAT32 USB partition:

8192

(value in MB)

Equivalent Hardware

Component	Equivalent
GPU	AMD RX 6700 (non-XT) - 36 CU, similar clocks
CPU	~AMD Ryzen 2700 (downclocked Zen 2, 8c/16t)

Benchmarks (Superposition 1080p Extreme)

Config	Score	Notes
No boost	4903	GPU @ 3193 MHz
Fan + boost, no CU unlock	~5150
40 CU + fan + boost	5041	GPU @ 3493 MHz actual, kernel 7.0.10
40 CU + fan + boost (CFI-1216A)	5259	6nm APU, highest seen

BC250 reference: 36CU@2200MHz = ~5336, 40CU@2200MHz = ~5530. Boost mode on PS5 may not always sustain full clock speed depending on thermals.

Performance Tips

• Remove idle=halt from cmdline.txt if you notice microstuttering - theflow asked community to test this
• If you see graphical issues in games, set RADV_DEBUG=nohiz (same recommendation as AMD BC250)
• Many tips from AMD BC250 Documentation apply to PS5 too