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Comment by kjs3 | Hacker News Reader

That's a weird measure of success.

It's a far better measure than "despite all the years of unfulfilled hype and promises we'll absolutely have a smorgasbord of performant RISC-V cores Real Soon Now". Single core performance down in the Intel Core range? Needs 96 cores to even be competitive on a handful of benchmarks that don't equal a modern users compute needs? The competition isn't sitting on their hands, and RISC-V hasn't delivered the performance it's fanbois have told us is 'inevitable'. Loongson has at least managed late-2010s levels of performance.

Maybe RISC-V will completely take over the embedded market. That's not a bad gig. High volume, tho slim margins, lot's of niches for lots of innovation (want to continue to go crazy with ISA extension? Not a big deal in the embedded world). But they're still selling billions of 8051s, ARM is ubiquitous but even they didn't take over that world, and I know how I would lay my bets there, too.

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That's using he most enthusiastic fanboy predictions as the baseline by which to judge success, not a recipe for reaching the right conclusions.

I'd rather look at all the data available. If you want to compare to Loongson, you have to include the 20 years head start that this company has in developing microarchitectures, a big part of which can be transferred to the Loongson designs. And factor in the strategic investments in China who doesn't want to depend on ARM and x86, while in the Western world people were happy with x86 and ARM and big money is mostly flowing to AI chips, where RISC-V is successful.

Then there is Xiangshan Kunminghu... For some reason the most powerful open source CPU is RISC-V. Chinese and not Loongson.

> I'd rather look at all the data available

There is no data to suggest RISCV can ever be competitive in the large core space. The longer this absence goes on (now approaching 15 years) the more evidence there is that it is structurally incapable of competitive implementations.

If you wanted to create a project to distract a whole generation of computer architects from getting anywhere this is exactly what it would look like.

RISC-V was a young, purely academic project in 2011. The pivot to industry came in 2015. This was followed by announcements by companies that they were shifting to RISC-V, but guess what, it takes time. For example Western Digital announced in 2017 but shipped only in 2021.

Now consider that RVA23 was ratified only two years ago, and the server platform specification 6 months ago! This bigger standardized base is important for larger cores, and of course these cores take longer to develop than the small ones like Western Digital's.

I share the frustration with the lack of competitive application cores (looks like extending an ISA through open and collaborative processes takes more time than in a company). But is it not a bit early to judge the ISA's potential based on the chips on shelves today?

Anyway large RISC-V cores do exist. The SiFive P870-D is a 6-wide core you can buy now with the BigSky SF-2U870. Ascalon (8-wide) has been available as IP for a while (though I will grant you I don't know how competitive it will be when it's finally taped out).

Oh and the Arbel by NextSilicon (10-wide, 480-entry ROB) has been taped out. Is that large enough?

But is it not a bit early to judge the ISA's potential based on the chips on shelves today?

Hopes and prayers are not a basis to judge hardware. No one will be sad about a 3rd option performant ISA, but call us when something competitive ships.

> There is no data to suggest RISCV can ever be competitive in the large core space.

There is also no data to suggest otherwise.

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