Hacker News Reader

Comment by daniel_iversen | Hacker News Reader

Wonder if any of the RISC-V cpus are fast enough as a daily driver running Linux? (Or maybe in phones or servers one day I’d that’s the intention) - I was trying to read about it and saw that people’s analysis show some of them are 28% slower than a raspberry pi 4[1] and “the RISC-V U74 core had roughly 1.8 times lower performance per clock compared to the ARM Cortex-A53”[2]. I guess if the gap between non-open cpus and risc-v is too large and you can’t have the same OS experience or battery experience etc then it might be hard to be successful in mainstream devices? I have no idea how it works but would love to hear what people think; and it’s cool that we have an open processor architecture that seems relatively capable and that’s making its way into different devices!

[1] https://www.reddit.com/r/RISCV/comments/1c1ikfp/eswin_eic770...

[2] https://www.reddit.com/r/RISCV/comments/1coxdwm/whats_the_cu...

View on HN

> Wonder if any of the RISC-V cpus are fast enough as a daily driver running Linux?

Short answer: Absolutely not, and you pretty much summarized it in your comment. RISC-V cpus are still at the performance level of Raspberry Pi 4, a $50 computer from five years ago.

I mean maybe not many of us here, but my mom’s daily driver is a Chromebook. I SSH into my server using a Core 2 Dup laptop, that could be replaced.

When I was commuting 2 hours a day on the bus, my daily driver was an 8-inch iPad that I used with a logitec keyboard case tethered to my iPhone for internet, and would connect to my VSCode on my $10/mo droplet using Code-Server.

If you offload the computer to the cloud, and don't need to do anything graphically intense, it makes daily driving an underpowered tablet very easy.

I mean, I keep a 10 year old MacBook in my kitchen/dining room. If someone were still actually making a high-end Chromebook that would be fine. Unfortunately with Google's departure from doing that hardware, it's all pretty much lower-priced educational market stuff and if I really needed a lightweight travel device, I'd get a tablet (which I did recently) or a MacBook Air. MacBooks are low enough maintenance that a good high-res Chromebook wouldn't really be enough cheaper or lighter to really buy you much.

> RISC-V cpus are still at the performance level of Raspberry Pi 4, a $50 computer from five years ago.

What do you mean "still"? Those are brand new RISC-V CPUs, or were a year ago when they came out.

The base RISC-V specification which the current cores implement (except the ones from the last couple of months) was not even formally frozen and published yet when the Pi 4 came out. Getting comparable RISC-V boards out in 4 years was a great effort. Note that the Pi 4 arrived eight years after the ARMv8-A spec was published.

That original spec doesn't contain a lot of important things such as SIMD which make a huge difference to those Geekbench scores. They are not comparing like to like.

By this time next year we'll have RISC-V boards performing better than the Pi 5, less than two years after it (possibly 1.5 years).

A year after that, RISC-V things currently well into their design pipeline will be somewhere between Zen 1 and Apple M1 performance.

The rate of progress is incredible. In the last 2-3 years many designers of current CPUs from Apple, Intel, AMD, Arm, Qualcomm have moved to RISC-V companies.

I don't think so, I run a CI on a VisionFive2 and it is terribly slow, takes ~8x compared to my Ryzen 3600 CPU. It's not helped by also having fairly limited IO speed on the NVMe side (board issue? unclear)

A 6 core OoO CPU with 6-wide µop issue running at 4.2 GHz is 8x faster than a 4 core in-order 2-wide CPU running at 1.5 GHz?

(6/4) * (6/2) * (4.2/1.5) = 12.6

Who would ever have guessed it might be 8x faster, without running the test?

In boards you can buy, there is spacemiT K1, the first RVA22+Vector1.0 SoC.

The boards are Banana Pi BPi-F3 (small SBC) and Milk-V Jupiter (mini-ITX).

The cores in there perform similar to -still usable- Intel Core 2, but there's eight of these cores, and presents a sizable improvement over the older VisionFive2's JH7110.

This review[0] by Explaining Computers shows how it is already usable in practice, using a launch day software image. Take note that newer board variants offer a more workable 16GB RAM.

Of course, having these boards means developers can now run RVA22+V in real hardware rather than simulators.

0. https://www.youtube.com/watch?v=GZGryhBnkV0

Reply on news.ycombinator.com