Files
ps3-undervolt/README.md
2026-08-03 13:22:58 +02:00

5.7 KiB

PS3 undervolting

Hunting two forums, two YT videos and several github repos for into kinda sucks.

Stable

For my Slim CECH-2004 with 45nm CELL and 65nm RSX.

Some dude here went down to 0.950 V on CELL and 0.993 V on RSX with CECH-2003, same DYN-001 board. Assuming stock clocks (500/650MHz).

CELL B.E.

Stock RSX

And stock VRAM

CELL RSX Tested?
1.025 V 0.900 V ✅ Didn't crash in ProStreet for like 30 min
1.025 V 0.875 V ✅ Didn't crash in ProStreet for like 1h
1.000 V 0.875 V ✅ Works for 20ish min in GTA 4
0.950 V 0.875 V ✅ Works for 15ish min in GTA 4

Overclocked 600 MHz RSX

And 750 MHZ VRAM

CELL RSX Tested?
1.050 V 1.000 V ✅ Didn't crash in ProStreet for like 30 min
1.025 V 1.000 V ✅ Didn't crash in ProStreet for like 20 min
1.025 V 0.975 V ✅ Didn't crash in ProStreet for 40 min
1.025 V 0.950 V ✅ ayy six seven didn't crash in ProStreet for 1h
1.025 V 0.925 V Crash minutes in.

1.025/0.950V is cool enough to run at ~73-74C and 33% fan.

How?

Hook up RX/TX pins

On Sherwood syscons you only need RX and TX, on Mullion you also need DIAG pin which needs to be grounded (?).

Where pins?

CECH-20xx

Gray is RX, white is TX, black is ground.

Clone this repo

python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python3 ps3_syscon_uart_script.py /dev/ttyUSB0 SW

/dev/ttyUSB0 is the serial port address, COMx on Windows. SW is the SYSCON type? For Sherwood just put SW.

Anything slim (CECH-20xx) and newer is Sherwood.

Looks like some late fat models also use Sherwood SYSCON but they have the same buck regulators as the early fats (NCP5318) so they use a different VID table.

Before you break it too hard

Good idea to dump the SYSCON memory.

python3 syscon_dump.py /dev/ttyUSB0 SW --start 0 --end 8000 -o backup_factory

You do have a backup of factory SYSCON memory in this repo.

Magic commands

command what do
auth authenticate with SYSCON
r xx 01 read programmed voltage. xx is the target chip, 50 - CELL, 51 - RSX. FF is default..
w xx yy program a new voltage. yy is the VID hex from the table below. Set VID to FF to reset to default
eepcsum display the checksum. See below
bringup start the console. Will reset video settings for some reason
errlog display last 32 error codes
powersw presses the power switch, v cool
shutdown immediately shuts down the console, not a clean poweroff, will fuck up the filesystem and trigger safe mode boot eventually

See also more commands and general SYSCON info.

On auth

Idk sometimes doens't work? Need to try multiple times. Also try AUTH. If it refuses to work you probably need to swap RX and TX pins.

Fix checksum

If you don't do this it might work until you unplug the power cord, and then then you're gonna get Red Light of Death (3 beeps and red blinking light as soon as you plug the cord in).

Sherwood

Run eepcsum, note the value in csum, then swap the bytes and write them to 7fe.

Like this:

>$ eepcsum
00000000
# csum = 0xDD9E

Press Ctrl+C to exit
>$ w 7fe 9e dd
00000000
# addr=000007FE num=02 val=9E DD

You spent 5h trying to figure this out, just remember to fix the checksum.

Mullion

eepcsum will literally tell you what you need to write and where, I think. I don't have a Mullion console.

VID table

For slim/super slim. Fats need a different one.

voltage VID hex
1,20000 V 3F
1,19375 V 40
1,18750 V 41
1,18125 V 42
1,17500 V 43
1,16875 V 44
1,16250 V 45
1,15625 V 46
1,15000 V 47
1,14375 V 48
1,13750 V 49
1,13125 V 4A
1,12500 V 4B
1,11875 V 4C
1,11250 V 4D
1,10625 V 4E
1,10000 V 4F
1,09375 V 50
1,08750 V 51
1,08125 V 52
1,07500 V 53
1,06875 V 54
1,06250 V 55
1,05625 V 56
1,05000 V 57
1,04375 V 58
1,03750 V 59
1,03125 V 5A
1,02500 V 5B
1,01875 V 5C
1,01250 V 5D
1,00625 V 5E
1,00000 V 5F
0,99375 V 60
0,98750 V 61
0,98125 V 62
0,97500 V 63
0,96875 V 64
0,96250 V 65
0,95625 V 66
0,95000 V 67
0,94375 V 68
0,93750 V 69
0,93125 V 6A
0,92500 V 6B
0,91875 V 6C
0,91250 V 6D
0,90625 V 6E
0,90000 V 6F
0,89375 V 70
0,88750 V 71
0,88125 V 72
0,87500 V 73
0,86875 V 74
0,86250 V 75
0,85625 V 76
0,85000 V 77
0,84375 V 78
0,83750 V 79
0,83125 V 7A
0,82500 V 7B
0,81875 V 7C
0,81250 V 7D
0,80625 V 7E
0,80000 V 7F
0,79375 V 80
0,78750 V 81
0,78125 V 82
0,77500 V 83
0,76875 V 84
0,76250 V 85
0,75625 V 86
0,75000 V 87
0,74375 V 88
0,73750 V 89
0,73125 V 8A
0,72500 V 8B
0,71875 V 8C
0,71250 V 8D
0,70625 V 8E
0,70000 V 8F
0,69375 V 90
0,68750 V 91
0,68125 V 92
0,67500 V 93
0,66875 V 94
0,66250 V 95
0,65625 V 96
0,65000 V 97
0,64375 V 98
0,63750 V 99
0,63125 V 9A
0,62500 V 9B
0,61875 V 9C
0,61250 V 9D
0,60625 V 9E
0,60000 V 9F
0,59375 V A0
0,58750 V A1
0,58125 V A2
0,57500 V A3
0,56875 V A4
0,56250 V A5
0,55625 V A6
0,55000 V A7
0,54375 V A8
0,53750 V A9
0,53125 V AA
0,52500 V AB
0,51875 V AC
0,51250 V AD
0,50625 V AE
0,50000 V AF