I may end up with a Radeon RX550 gfx card, full size (well, not low profile, but seems to be fairly compact although it's two ports wide), due to an admin error.
So.. given I have a SAM440EP and I haven't opened anything up to see whether it would physically fit, and have no idea whether this thing is in any way compatible (hardware or software).
I think I might need a riser? And maybe the latest SAM firmware? And it looks like this card might have drivers? Is it possible it would work?
if you have little Sam440ep, don't use this card. It works, but this Sam has only 33 MHz PCI slot, so it will be very slow.
if you have Sam440ep-flex, it can be good option. Look into this article> Sam440ep-llex graphics cards. Article is from 2021, when Polaris cards (like yours RX550) not worked in Sam440, but today they worked. Your RX550 will be faster than HD7750 in article.
You will need: - PCI-PCIe adapter and powered PCIe riser - new UBoot from ACube - Enhancer 2.2 ( with RadeonHD and Warp3D Nova drivers ) - Optionally also NovaBridge for Warp3D compatibility.
AmigaOS3: Amiga 1200 AmigaOS4: Micro A1-C, AmigaOne XE, Pegasos II, Sam440ep, Sam440ep-flex, AmigaOne X1000 MorphOS: Efika 5200b, Pegasos I, Pegasos II, Powerbook, Mac Mini, iMac, Powermac Quad
Just out of curiousity, with a 33MHz PCI slot, are there are graphics cards that are worthwhile?
Nothing comparable to PCIe Radeon HD/RX cards nor usable for current OpenGL software, but for example a PCI ATI Radeon 9250 with 256 MB VRAM is probably still better than the onboard Radeon M9 with only 64 MB VRAM.
Generally, all cards mentioned in Sam440ep-flex gfx card article incl. your RX550 probably will work. Only they will be slow. If you check block diagram - internal Radeon M9 is on 66 MHz PCI bus, but external PCI slot is behind the PCI bridge on 33 MHz bus. Real measured speed on my Sam440ep: internal M9: CopyToVRAM 40 MB/s, WritePixelArray 87 MB/s PCI 9200 SE: CopyToVRAM 18 MB/s, WritePixelArray 60 MB/s PCIe cards like RX550 will be even slower becouse of PCI-PCIe bridge latency.
So you can use RX550, but in practice all Warp3DNova or OGLES application will be terribly slow.
Only good reason why to use external card is, as joerg said, if you need more VRAM. For example, in article is screenshot with SysMon/System and in bottom you can see Radeon 9200 SE 128MB connected ( via PCI-AGP adapter ).
Edited by sailor on 2026/2/3 18:02:35
AmigaOS3: Amiga 1200 AmigaOS4: Micro A1-C, AmigaOne XE, Pegasos II, Sam440ep, Sam440ep-flex, AmigaOne X1000 MorphOS: Efika 5200b, Pegasos I, Pegasos II, Powerbook, Mac Mini, iMac, Powermac Quad
The Sam440ep-Flex is not really worth equipping with a Radeon RX or HD graphics card. Most games that require OpenGL ES–level graphics do not run at a playable speed, even when the original CPU requirement was only a 166 MHz PowerPC processor. At the same time, a large portion of games that rely on MiniGL stop working altogether.
While this setup can be experimented with, the required software is expensive enough that the overall experience ends up being a major disappointment. I ended up reinstalling a Radeon 9250 graphics card in my Sam440ep-Flex system.
UBoot works with Polaris, graphicsc output is visible, can select kickstart, modules loaded Then it hangs with "Loading done, launching kickstart"
Serial debug:
U-Boot 2015.d (Apr 07 2025 - 16:10:29)
CPU: AMCC PowerPC 440EP Rev. C at 733.333 MHz (PLB=146 OPB=73 EBC=73 PCI=73 MHz)
Bootstrap Option H - Boot ROM Location I2C (Addr 0x52)
Internal PCI arbiter enabled, PCI async ext clock used
32 kB I-Cache 32 kB D-Cache
Board: Sam440ep-flex
I2C: ready
DRAM: 1 GiB
PCI: Bus Dev VenId DevId Class Int
01 04 1013 6005 0401 00
01 05 1033 0035 0c03 00
01 05 1033 0035 0c03 00
01 05 1033 00e0 0c03 00
00 0a 12d8 8150 0604 00
02 00 1002 67ff 0300 ff
02 00 1002 aae0 0403 ff
00 0c 12d8 e111 0604 00
00 0e 1095 3114 0180 00
Net: ppc_4xx_eth0, ppc_4xx_eth1
SM502: not found
PERMD2:not found
VGA: OK
VESA: OK
RadeonRX (2): Identified the chipset as: POLARIS11
RadeonRX (2): Graphics card name is: Radeon RX Polaris11
RadeonRX (2): If - and only if - your card does not work or does not work optimally
please submit a bug report at:
http://www.amiga.org/developer/bugreports
Remember to include the driver version, and the following card details:
0x67FF:0x1462:0x8A91:
and *please* describe the problems you are seeing in detail.
graphics.library PPC440ep optimizations enabled
RadeonRX (0): RadeonRX.chip 2.12 (24.8.2022)
RadeonRX (2): Identified the chipset as: POLARIS11
RadeonRX (2): Graphics card name is: Radeon RX Polaris11
RadeonRX (2): If - and only if - your card does not work or does not work optimally
please submit a bug report at:
http://www.amiga.org/developer/bugreports
Remember to include the driver version, and the following card details:
0x67FF:0x1462:0x8A91:
and *please* describe the problems you are seeing in detail.
RadeonRX (0): System doesn't have full memory coherence. Compensating...
So, UBoot works very well, but probably RadeonRX driver has issues.
P.S: on weekend I will try with update 3 + RadeonRX.chip.debug
Edited by sailor on 2026/2/6 19:28:33
AmigaOS3: Amiga 1200 AmigaOS4: Micro A1-C, AmigaOne XE, Pegasos II, Sam440ep, Sam440ep-flex, AmigaOne X1000 MorphOS: Efika 5200b, Pegasos I, Pegasos II, Powerbook, Mac Mini, iMac, Powermac Quad