Suggestion on An Expansion Card

I recently preordered my HiFive Unmatched and am thinking I should start an expansion parts list. Does anyone have any suggestions on what to put in the PCI slot that would work with the computer? I am considering getting some type of all-in-one card but not sure what that could be.

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I’ve got a Sapphire Radeon R5 230 graphics card (max power use 19W) waiting here. It was about $50 a month or two ago.

Also planning to try it on the Icicle board once that arrives. I’m less sure about it there, but it should I expect work no problems on the Unmatched.

Interested to know what you find.

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I would suggest sticking with things that have already been tested by SiFive, unless you want to do some work on linux kernel device drivers. It may be a while before the driver support is as good as an x86 or arm computer. Pretty much anything can be connected via USB these days, and USB multiport hubs are cheap, so we have primarily been using the PCI slot for a video card. This link
under the software features/linux bsp section mentions the two video cards we are testing, along with the NVME card we use, and the wifi card we are testing. Also, you might want to wait until the unmatched board is closer to available, as it is possible our recommendations might change if we run into problems during testing. I would expect docs to be released with the board that have more info about what is recommended for use with the board.


The RX580 uses 150W! That’s an absolute beast of a card. I’ve never had anything close to that in any PC I’ve ever owned. It also costs $300! I’ve never spent more than about a third of that on a video card.

For sure it’s not going to work powered from an Icicle, which only has a 60W power supply.

I’m going to try my $50 Radeon. It uses the same (open source) driver.

Just what I needed. I will keep an eye out for those chipsets. But you have a good point, I should wait until I actually get the board before buying something that may later not be supported or if more things are added that are supported.

For my game dev day job I have AMD GPUs for every generation (going back to Polaris, so RX5xx, Vega, Radeon VII, Navi, and big Navi) . I will test all of them and I will report it back here! I was planning to do that anyway out of curiosity. If it can help people even better!


What a cool idea. Thank you.

I’ve got an RX 550 lined up for it. There really shouldn’t be any trouble with it as long as the PCIe controller works properly; PCIe was designed to be architecture-independent, and if AMDGPU runs at all on this chip, any graphics card it supports should also, in theory, run just fine.

Let me know if anyone wants an AliExpress shop where you can grab an RX550 for US$90.

I was planning on either a RX580 or WX7100 myself. Would love to see some videos of the board actually running other than the marketing clips.

Maybe set one up and give unprivileged SSH access to it as a marketing stunt. :3

[snarky comment]What a great idea for testing denial of service attacks!

We could also see how many thousands of people could login before crashing![/snarky comment]

Snarky comment aside, their are vendors who do make remote equipment available for testing applications and user interfaces. But, usually that is limited to specific people for a limited time.

However, in this case, other than looking at “/proc” and “/sys” entries, it should be plain Linux.

Thousands of people being interested in RISC-V Linux would be a nice problem to have :slight_smile:

It seems 113 people have ordered 131 boards on CrowdSupply, and another 240 boards have been ordered on Mouser.

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@bruce, I never said those thousands of people logging in to an open test box would actually be interested in RISC-V Linux computers. Some would just be curious. Others to see what they can do, (like if they can SSH in, can they SCP in files or programs and start bit-coin mining…). Worse, if the open box was mentioned on SlashDot, you might get the SlashDot effect, (basically thousands of people trying it out at once, guess what happens).

371 boards is actually pretty decent for the moment. Some of us just don’t have the time to assist with software development and trouble shooting. So I personally am waiting to see what the early adopters can accomplish.

I know what slashdotting is :slight_smile: I’ve been a member since the late 90s and my personal web server has been slashdotted a few times, including as long ago as 2001. Fortunately, it held up fine as despite having only a 166 MHz MIPS CPU all my pages were static HTML and it was in a cohosting place with big pipes.

@jimw that link (as of today) doesn’t mention the cards being tested yet, any idea when that will be available?

Also - what do people think of the Radon 550X? It seems to be the best available choice if I want to keep the TDP at 50W.

(my board is scheduled to ship in March so I’m looking at options)


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Ah, looks like the Getting Started Guide is available and recommends the RX 500-series


Yes, see the Getting Started Guide for a list of tested peripherals.

The GSG says the power supply must provide at least 150W. Earlier versions had an incorrect higher number.

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I have a Radeon Pro WX 5100 – I wonder if this will work… Hrm.

If you already have it, it’s worth a shot trying it. If it doesn’t work, you can get RX550s cheap from AliExpress.

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i had a look and sprung for one if those sketchy Yeston rx550 cards. love that it has vga on it too. Cheap and 40w – Thanks!

Ill keep my bougey radeon pro where it is.