upvote

points

by dmitrygr4 hours ago |
comments
upvoteby topspin4 hours ago|
next
[-]
I keep checking in on Tenstorrent every few months thinking Keller is going to rock our world... losing hope.

At this point the most likely place for truly competitive RISC-V to appear is China.

reply
upvoteby Findecanor1 hours ago|
parent|
next
[-]
Tenstorrent is supposedly taping out 8-wide Ascalon processors as we speak, with devboards projected to be available in Q2/Q3 this year.

BTW. Keller is also on the board of AheadComputing — founded by former Intel engineers behind the fabled "Royal Core".

reply
upvoteby rbanffy4 hours ago|
parent|
prev|
[-]
> At this point the most likely place for fast RISC-V to appear is China.

Or we just adopt Loongson.

reply
upvoteby balou234 hours ago|
parent|
next
[-]
TBH I still don't really get how it's different from MIPS. As far as I can tell... Loongson seems to be really just MIPS, while LoongArch is MIPS with some extra instructions.
reply
upvoteby bonzini3 hours ago|
parent|
next
[-]
LoongArch is, on a first approximation, an almost RISC-V user space instruction set together with MIPS-like privileged instructions and registers.
reply
upvoteby mananaysiempre1 hours ago|
parent|
[-]
Wait, this is a modern-ish ISA with a software-managed TLB, I didn’t realize that! The manual seems a bit unhappy about that part though:

> In the current version of this architecture specification, TLB refill and consistent maintenance between TLB and page tables are still [sic] all led by software.

https://loongson.github.io/LoongArch-Documentation/LoongArch...

reply
upvoteby pantalaimon3 hours ago|
parent|
prev|
next
[-]
They did get rid of the delay slots and some other MIPS oddities
reply
upvoteby mananaysiempre4 hours ago|
parent|
prev|
[-]
But legally distinct! I guess calling it Ｍ○ＰＳ was not enough for plausible deniability.
reply
upvoteby genxy4 hours ago|
parent|
[-]
ISAs shouldn't be patentable in the first place.
reply
upvoteby throawayonthe3 hours ago|
parent|
prev|
[-]
(purely on vibes) loongson feels to me like an intermediate step/backup strategy rather than a longterm target (though they'll probably power govt equipment for decades of legacy either way :p)
reply
upvoteby rbanffy4 hours ago|
prev|
next
[-]
I did read it. A Banana Pi is not the fastest developer platform. The title is misleading.

BTW, it's quite impressive how the s390x is so fast per core compared to the others. I mean, of course it's fast - we all knew that.

And don't let IBM legal see this can be considered a published benchmark, because they are very shy about s390x performance numbers.

reply
upvoteby Aurornis4 hours ago|
parent|
next
[-]
> A Banana Pi is not the fastest developer platform.

What is the current fastest platform that isn’t exorbitantly expensive? Not upcoming releases, but something I can actually buy.

I check in every 3-6 months but the situation hasn’t changed significantly yet.

reply
upvoteby cestith4 hours ago|
parent|
next
[-]
What is the current fastest ppc64le implementation that isn’t exorbitantly expensive? How about the s390x?
reply
upvoteby adgjlsfhk12 hours ago|
parent|
prev|
[-]
A P550 based board is the best you can get for now (~2-3x faster than the Banana Pi). In 2-3 months there should be a number of SpaceMIT k3 chips that are ~4-6x faster than the banana pi and somewhat reasonably priced (~200-300). By the end of the year, however, you should be able to get an ascalon chip which should be way way faster than that (roughly apple m1/zen3 speed)
reply
upvoteby gt04 hours ago|
parent|
prev|
next
[-]
I was really surprised by the s390x performance, but I also don't really understand why there are build time listed by architecture, not the actual processors.
reply
upvoteby kpil3 hours ago|
parent|
next
[-]
What's fast on Z platforms is typically IO rather than raw CPU - the platform can push a lot of parallell data. This is typically the bottleneck when compiling.

The cores are in my experience moderately fast at most. Note that there are a lot of licencing options and I think some are speed-capped - but I don't think that applies to IFL - a standard CPU licence-restricted to only run linux.

reply
upvoteby burntoutgray21 minutes ago|
parent|
[-]
I thought I read somewhere that Z CPUs run at 5GHz ??
reply
upvoteby rbanffy4 hours ago|
parent|
prev|
next
[-]
Probably because that's just the infrastructure they have.
reply
upvoteby pantalaimon3 hours ago|
parent|
prev|
[-]
i686 builds even faster
reply
upvoteby menaerus4 hours ago|
parent|
prev|
[-]
Which risc-v implementation is considered fast?
reply
upvoteby LeFantome2 hours ago|
parent|
next
[-]
> Which risc-v implementation is considered fast?

SpacemiT K3 is 2010 Macbook performance single-core, 2019 Macbook Air multi-core, and better than M4 Apple Silicon for AI.

So I guess it depends on what you are going to do with it.

reply
upvoteby patchnull4 hours ago|
parent|
prev|
next
[-]
Nothing shipping today is really competitive with modern ARM or x86. The SiFive P870 and Tenstorrent Ascalon (Jim Keller's team) are the most anticipated high-performance designs, but neither is widely available. What you can actually buy today tops out around Cortex-A76 class single-thread performance at best, which is roughly where ARM was five or six years ago.
reply
upvoteby menaerus4 hours ago|
parent|
next
[-]
I remember taking down some notes wrt SiFive P870 specs, comparing them to x86_64, and reaching the same conclusion. Narrower core width (4-wide vs 8-wide), lower clock frequency (peaks at 3GHz) and no turbo (?), limited support for vector execution (128-bit vs 512-bit), limited L1 bandwidth (1x 128-bit load/cycle?), limited FP compute (2x 128-bit vs 2x 512-bit), load queue is also inconveniently small with 48 entries (affecting already limited load bandwidth), unclear system memory bandwidth and how it scales wrt the number of cores (L3 contention) although for the latter they seem to use what AMD is doing (exclusive L3 cache per chiplet).
reply
upvoteby LeFantome2 hours ago|
parent|
prev|
[-]
SpacemiT K3 is about the same performance as a Rockchip RK3588. So, 4 years ago?

Except the K3 kills it on AI (60 TOPS).

reply
upvoteby NooneAtAll34 hours ago|
parent|
prev|
[-]
DC-ROMA 2 is on the Rasperry 4 level of performance last I heard
reply
upvoteby tromp4 hours ago|
prev|
next
[-]
But they didn't reflect that in a title like "current RISC-V silicon Is Sloooow" ...
reply
upvoteby spiderice4 hours ago|
prev|
[-]
Then how do you justify the title?
reply