FYI, the previous (probably more expensive) Banana Pi BPI-F3 is faster and has more cores.
This one has 4 C908 cores @1.25GHz with VLEN=128 and the BPI-F3 has 8 X60 cores @1.6GHz with VLEN=256.
Both are simple in-order cores and they are likely even based on the same predicessor implementation.
Edit: Actually, I don't know the VLEN, but previous boards with C908 had 128-bit vectors. The IP is configurable, so it could also have a larger VLEN, or no vector support at all.
Edit2: It might be no vector support at all, since the device tree doesn't list support for the "V" extension: https://github.com/BPI-SINOVOIP/BPI-RV2-SF21H8898-OPENWRT-BS...