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by adgjlsfhk1 502 days ago
Unfortunately the K1 is horribly slow. It's an in order processor, doesn't have L3 cache and has pretty slow floating point multiplies. It's an OK dev board for riscv-V, but it is closer to Raspberry pi 3 than the P550 which is a lot closer to a Pi 4 for general performance.
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Yes, it was very disappointing. I was hoping the 8 cores would give a speedup for compiling code, but no dice. On a large Linux build, the BPI-F3 with make -j8 takes exactly the same time as a make -j4 on the VisionFive 2.
Nothing except the Pioneer (and now this and the Milk-v P550) has L3 cache.

BPI-F3 (etc) has only 512 MB of L2 cache for each cluster of 4 cores, vs 2 MB on the VisionFive 2 (etc), and I think this is the biggest issue. Similarly the TH1520 only has 1 MB of L2.

The Pioneer has the same 1 MB of L2 per four cores, but backs this up with 4 MB of L3, and when you're running single-threaded (or just a few) that CPU also has access to the other 60 MB of L3 cache on the chip at still much better than DRAM latency and bandwidth. It's very nice-perofrming machine if you can afford it -- though the P550 should make a better desktop machine. I'll know in a week or two when my Megrez arrives...