Rockpi, raspberry pi, orange pi all have 4 or 6 core arm64 sbc.
A raspberry pi might be good for very small scale experimentation of little apps, but my 4GB model took months to arrive and doesn't come close to matching the performance of the smallest instance I would use at $DAYJOB.
https://www.forbes.com/sites/moorinsights/2019/11/18/nuvia-d...
https://www.friendlyarm.com/index.php?route=product/product&...
Architecture: aarch64
Byte Order: Little Endian
CPU(s): 4
On-line CPU(s) list: 0-3
Thread(s) per core: 1
Core(s) per socket: 4
Socket(s): 1
NUMA node(s): 1
Vendor ID: ARM
Model: 4
Model name: Cortex-A53
Stepping: r0p4
CPU max MHz: 1296.0000
CPU min MHz: 120.0000
BogoMIPS: 48.00
NUMA node0 CPU(s): 0-3
pi@raspberrypi:~ $ lscpu
Architecture: armv7l
Byte Order: Little Endian
CPU(s): 4
On-line CPU(s) list: 0-3
Thread(s) per core: 1
Core(s) per socket: 4
Socket(s): 1
Vendor ID: ARM
Model: 4
Model name: Cortex-A53
Stepping: r0p4
CPU max MHz: 1400.0000
CPU min MHz: 600.0000
BogoMIPS: 38.40
Flags: half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32edit: and somehow omitted the
Flags: fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid