Which risc-v implementation is considered fast?

LeFantome 5 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.

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patchnull 7 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.

	▲	menaerus 7 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).
	▲	LeFantome 5 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).

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NooneAtAll3 7 hours ago | parent | prev [-]

DC-ROMA 2 is on the Rasperry 4 level of performance last I heard