Milk-V Duo: A $9 RISC-V Computer (opens in new tab)

While the BL808 (what the Ox64 uses) can nominally run Linux, it doesn't really work for that in practice because of design issues in the chip (or to put it differently: it was never designed for that purpose - the C906 core was included to be used as a DSP. The MMU etc. is just incidential.). Almost all peripheral interrupts (such as the the SD controller, Ethernet MAC, etc.) are routed to the E907 core (which is more comparable to a Cortex-M "microcontroller" core in the ARM world). Thus, doing anything useful with it with Linux requires ugly IRQ forwarding hacks. The community is working on that, but it's always going to be a Rube Goldberg thing that I'm not sure upstream will ever accept. I really hope the chip manufacturer realizes what they are sitting on and adds the ability to mux the IRQ lines in a later design.

The documentation on the CV1800B is still pretty light, but what I've seen suggests it does not suffer from the same issue, so that alone makes this board much more interesting than the Ox64.

Yes, but pine64 shipping is a serious pain point for many regions. I used to buy lots of cheap stuff from them with "EU standard shipping" to Poland that cost like 10eur. This shipping method has disappeared to Poland and many other EU countries last year. Last time I checked they wanted 35eur for shipping.

I'm not paying that when buying a $9 board.

OT, is pinephone making some progress?

I have not heard about them in quite some time, but was hoping they eventually reach the point, of offering a usable device. I guess they are still not there?

There are no Linux drivers for Bluetooth and Wi-Fi as of yet. Not sure about USB and microSD (for booting).

128mb now

> What's the selling point of 64MB of RAM with a 1GHz CPU?

Well, the first server I ran had 64MB of RAM and, IIRC, a 0.6GHz CPU. Ran slackware with apache and my software was written in C as CGI scripts (generated charts on page visits using, IIRC, libgd).

You can do a lot.

You won't do it in JS or Python or Ruby or C# or Java, and you won't produce AAA games or ML or cryptocurrency or similar, but you can write you useful software that runs snappily on a 64MB/1GHz machine.

TBH, I can't think of much that a 64MB/1GHz machine cannot do.

People got a lot done in the Pentium II / III era of computing. Dell shipped 32 and 64MB of RAM as the basic standard on their lines that also offered 1Ghz CPUs at the time[1].

I think it's easy to be unaware of how vastly speed outpaced memory density at some points. It's kind of what we saw a few years ago with core counts and limitations on DDR3 and early DDR4.

[1]: https://dl.dell.com/manuals/all-products/esuprt_desktop/esup...

It can achieve > 90 percent of the computing tasks on the planet, outside of datacenters, smartphones, and PCs.

But IMHO the price is the sticking point because nearly the same can be said of an a esp32-s2 (riscV) and it has better peripherals, built in WiFi and Bluetooth, and sells for <$2 soldered on a dev board.

I think the fit here is for edge-AI. The asynchronous multiprocessing might actually be a winner here, since you could run your time-unpredictable algorithms on the Linux core and run your real-time needs on an ratos or bare metal on the other core… so kinda like a 2 in one device? Still not sure if that tracks for most cases though since a discrete RTOS/Bare metal core is about 0.5usd to solder next to your application processor.

I think something around this price point with a strong TPU integrated might make sense, especially since it seems to compare favourably with the kendryte k210 which has proven very popular in edge-AI image processing. The question here is whether or not the vector unit will compare well with the NPU on the K210 or not, and whether the power budget is good enough for battery powered devices.

On the Linux side, possibly some network service or IoT device running a OpenWRT like OS that does the bare minimum. Although in my opinion advertising this device as a Linux board isn't the best selling point, they do that also because today due to chips shortage and bumped prices everyone is looking for RPi alternatives, but to me it rather appears a really good board for a RTOS, in which case the available resources would be plenty. H264/5 video encoding makes it very interesting though, but I would put it behind a firewall anyway, if not because it's a unknown CPU and network stack from a unknown manufacturer.

Only those 2 specs ? Home routers, don't need much more to pass thru a gigabit of traffic with some firewall/NAT in place.

On board that only have 100Mbit ethernet? Much less useful but you could make a sound processor (effects etc), but then pinout doesn't show any I2S....

I guess you could do some image processing but RAM will be limit on that

The ESP32 microcontroller has 320Kb of RAM, and a dual core 240MHz CPU. It's is one of the most useful microcontrollers out there.

64MB and 1GHz CPU is a lot more and a lot faster, so IOT and edge-computing are able to process data locally.

The RAM seems a little odd.

For instance the rpi zero is 1ghz, but has 512mb of ram.

"Eschew flamebait. Avoid generic tangents."

https://news.ycombinator.com/newsguidelines.html

To some extent I agree with you, but I don't think this is a good example.

These types of "computers" are pretty simple electronics. All the complexity lives inside the "System on chip" - the engineer then picks a few supporting chips and makes sure the signal routing is matched. I wouldn't be surprised if the whole thing is based on a reference design from the SoC designer.

In this case, the west basically already competes - this is pretty similar to the raspberry pi zero. There's plenty of Western designed SoCs - which is where the complexity and IP lie.

All those SBCs are copying the Raspberry Pi range. But they go all in on hardware and tend to be lacking on the software and documentation sides compared to the various Pi.

For example, the Pi Pico comes with nice SDKs, comprehensive documentation, and can be flashed with a simple file drag and drop as they made it show as an USB drive.

So I'd say the West is still leading on this...

I don't think there is enough of a desire in the west to waste time pumping out non-innovative low spec trash. They follow the manta of "I skate to where the puck is going to be, not where it has been." For everything else, there is China after all.

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Here is what I found:

Minimal Documentation: https://milkv.io/docs/duo/getting-started/cv1800b Datasheet: https://github.com/milkv-duo/hardware

Reading the datasheet, it looks like there is one C906 cpu with 700 Mhz without the the vector extension and one C906 cpu at 1Ghz with rvv 0.7.1. The C906 design has been opensourced and is available here: https://github.com/T-head-Semi/openc906

The C906 supports rv64gc with optional rvv 0.7.1 with a vlen of 128, but a 256 wide ALU.

They list H.264/H.265 support, but I don't think it's a standardized extension.

But see my other comment about using the pre ratification vector extension: https://news.ycombinator.com/item?id=36377439#36378911

Exactly the same, RV64 or RV32, USB device hardware block?

Would a spec sheet really help? For the use cases you are talking about, I wouldn't want to touch anything that doesn't come with actual datasheets and application notes, unless you're just doing it for fun. (i.e. the lack of spec sheet isn't really the obstacle here)

Also, is that mainline Linux or are we going down the hacked kernel route of the ARM boards where someone is going to have to pick through the source to get the patches otherwise it will remain on an ancient unsupported kernel?

Taobao has several stores selling it at around 68rmb which is a bit more than $9 at current FX. I'm quite curious about it and just ordered one, should get it in a couple days.

What do you (and people in general) mean by "intelligent"?

What's an "intelligent" lock, switch, light, or thermostat, for instance?

A priori a dual core CPU at 1GHz and 64MB of RAM is huge for one of those devices.

I don't see the point in comparing this to a rpi pico. Totally different niches.

Good find, one of the pictures says "RV64".

I think this might just be an unfortunate abuse of terminology. I've seen plenty of people similarly refer to the Raspberry Pi as having a "40-pin GPIO header", even though only a subset of those 40 pins actually have GPIO functionality.