SiFive's First Server Platform
chipsandcheese.com
chipsandcheese.com
I wonder how the driver situation is. From Jeff Geerling's work on running "big" GPUs on Raspberry Pis, my impression is that often less-common platforms should work but are littered with papercuts in practice.
While thinking about it, if NVIDIA or SAMSUNG go performant RISC-V CPU micro-architecture, will "probably" change the world.
I had thought Xilinx ISE and Altera Quartus had the market cornered on the most difficult environments to get running, but then LLMs and stable diffusion came along.
These tools were the reason why I gave up on FPGAs years ago and chose to spend my time on GPUs instead. And to this day, I still don't understand why they worked so differently from what I had expected in so many ways.
Yosys is a super lightweight open-source FPGA toolchain that really easy to get up and running. The FPGA models I mentioned have ~5k to ~10k LUTs, can all support simple RISC-V processors, and have built-in memory and DSPs.
oh a double wide surprise for the AI industry? just what we needed.
Drivers still need tweaking, most of the time, since most are still built assuming an amd64 world.
Lock-in to x86 or ARM is painful from an operator like AWSs perspective. With x86 you end up with two vendors to play off against each other, which isn't great. ARM gives you the ability to design your own silicon, but you're still beholden to a single licensor -- arguably worse. On top of that, some customers mandate a specific ISA or even a specific vendor, so none of it is truly fungible outside vertically integrated workloads like S3.
The ideal scenario for a hyperscaler is an open architecture at the core with 10+ competing implementations -- including potentially their own.
This is what Arm actually is. Arm primarily functions as a talking shop for random insights to get back from integrators into the ISA and architecture, then cleared and released for everyone to use. The reason there are so few novel implementations of it is it just isn’t worth the trouble unless you are pushing mobile levels of units.
I would be very interested to be a fly on the wall when a customer attempts to mandate to AWS they must support an ISA that AWS doesn't have plans to support out, say, a decade[1]. That would be almost as amusing as the many, many times I've heard clients say "we spend $X million dollars with Microsoft! We're a Big Company! We have leverage! Of course they'll do what we want!". And the local M$ salesthing just smiles nods and says "I'll get back to you on that..." and for some reason Nadella doesn't return their calls.
[1] Maybe if one of the big nations says "thou shalt only use our glorious domestic processor, and the processor of thine enemy shall be verboten, for all the data things" or some such...but not a commercial enterprise.
There's still a missing piece in the RISC-V ecosystem: a coordination body of platform-level standards. Debian took a stand with RVA23 support but then there's a ton of little things that are taken for granted on the PC platform such as UEFI and ACPI (as horrible as they may be).
Debian? Sure you don't mind Ubuntu?
is it opensource or megs of blob?
Surely between the squeeze on RAM and storage pricing and the exorbitant costs of training or mass-inference scale GPUs (if you’re going into AI), the nominal cost of the CPU licensing is really not going to make or brake anything or unlock some new business viability?
Even RISC-V aside, we are essentially in a position that would have been impossible to even dream of ten or twenty years ago when Intel was the only player in the game.
Wouldn’t buying off-lease hardware (not even in bulk) give you better performance per dollar, better compatibility, and more options?
Not to say any of this will always be the case; even if RAM pricing doesn’t come down, storage will, and RISC-V processors will (maybe) eventually actually be competitive when it comes to SOTA performance, but today in 2026?
In the embedded / microcontroller space it's a different story. License cost there must be absolutely key, and I think less vulnerable on a per unit basis to the RAM etc storage factors you mention. I don't actually know the numbers but I'd expect that as a percent of total BoM cost the ARM license must be higher for microcontrollers than bigger machines? Maybe someone more qualified knows the answer to this.
Instead, it’s that Moore’s law keeps on trucking along, so now we have lots of dark silicon (you cannot turn the whole core on at once, or it will turn into a puddle of glass) and specialized silicon.
RISC-V removes all the gatekeepers (except TSMC and the other fabs) that historically blocked new specialized silicon.
I could get an ARM license, but suspect that, at best, that means dealing with sales folks and also building out a legal division just to manage the license.
I could be wrong, but it’s easier to go with the open core, in the same way that I suspect I cannot afford to figure out how much I would have to pay in order to license windows for my servers.
Its not the cost that is the major change, its the business model.
Granted ARM potentially gives you part of that, but its still tricky.
And of course this theory only works out if you have enough competitive providers. But that's always questionable.
A 2U dev unit? Seems a bit premature..
Even knowing nothing about performance, knowing that it is N6 means it probably isnt particularly power efficient (as compared to leading edge x86/ARM).
https://www.sifive.com/blog/sifive-empowering-a-new-era-of-d...
According to that graph, the P870 has 80% of the performance of Ice Lake.
We can compare performance with other TSMC N6 designs. Even more so if we also know the area and power.
>not going to outperform anything from the past decade's worth of amd64 products.
This isn't some U74. This is P870. Its published performance data is no joke.
I was curious to see how far RISC-V still have to go from a microarchitecture stand point, but even in the same silicon process level, there are other things to take into account: the RISC-V compiler support, and something which is really new: since RISC-V is a non-IP-lock worldwide standard, assembly writting is much more a reasonable thing.
Knowing it is TSMC N6 unlocks at least this much.