Here is a preliminary report:

Each program was run on MacOS 11.1 using machine with Apple M1 (4+4 cores, 16GB RAM).
All data were compared with CRuby3.0.0.

Optcarrot is a NES emulator, and a semi-official benchmark program for Ruby, on https://github.com/mame/optcarrot.
You can see the results of optcarrot benchmark for ruruby and other Ruby implementations here.

benchmark	CRuby	ruruby	rate
optcarrot	56.09 ± 0.13 fps	34.80 ± 0.08 fps	x 1.61
optcarrot --opt	130.53 ± 0.82 fps	101.85 ± 1.08 fps	x 1.28

* With --opt option, optcarrot rewrites its own code for optimization.
Frames per seconds are shown.
The higher, the better.

benchmark	CRuby	ruruby	rate
accessor_get.rb	0.42 ± 0.00 s	0.43 ± 0.00 s	x 1.02
accessor_set.rb	0.48 ± 0.00 s	0.53 ± 0.00 s	x 1.10
ivar_get.rb	0.52 ± 0.00 s	0.63 ± 0.00 s	x 1.21
ivar_set.rb	0.52 ± 0.01 s	0.66 ± 0.01 s	x 1.25
loop_times.rb	0.72 ± 0.01 s	0.60 ± 0.00 s	x 0.84
loop_for.rb	0.78 ± 0.01 s	0.71 ± 0.00 s	x 0.91
loop_whileloop.rb	0.52 ± 0.00 s	0.48 ± 0.01 s	x 0.93
so_concatenate.rb	0.51 ± 0.01 s	0.48 ± 0.01 s	x 0.94
string_scan_str.rb	0.63 ± 0.00 s	0.88 ± 0.01 s	x 1.40
string_scan_re.rb	0.95 ± 0.00 s	0.87 ± 0.01 s	x 0.92
fiber_allocate.rb	0.59 ± 0.01 s	0.41 ± 0.04 s	x 0.69
fiber_switch.rb	0.64 ± 0.00 s	0.52 ± 0.01 s	x 0.82
so_mandelbrot.rb	1.18 ± 0.04 s	1.36 ± 0.01 s	x 1.15
app_mandelbrot.rb	0.84 ± 0.00 s	0.95 ± 0.00 s	x 1.13
app_fibo.rb	0.54 ± 0.01 s	0.68 ± 0.00 s	x 1.25
app_aobench.rb	5.89 ± 0.01 s	9.74 ± 0.03 s	x 1.65
so_nbody.rb	0.76 ± 0.01 s	0.94 ± 0.00 s	x 1.22

Mean and SD of execution time (executed 8 times) in seconds are shown.

The lower, the better.
These programs are available on https://github.com/ruby/ruby/blob/master/benchmark.

The characteristics of the benchmark programs are described below.

Simply execute a times method with block repeatedly.

Simply execute a for-loop repeatedly.

Simply execute a while-loop repeatedly.

Join small strings repeatedly.

A lot of arythmetic calculations with local variables in for-loop, producing almost no objects.

Produce and consume a lot of objects, and execute numerous method calls.

A huge number of recursive method calls.

Produce and consume a lot of objects, executing a huge number of floating point calculations and method calls.

To investigate memory consumption, maximum resident set size was measured using gnu-time. Memory consumption of ruruby is around 20%-25% as compared with CRuby.

benchmark	CRuby	ruruby	rate
simple_call.rb	26.7M	3.5M	x 0.13
accessor_get.rb	26.6M	3.5M	x 0.13
accessor_set.rb	26.7M	3.5M	x 0.13
ivar_get.rb	26.6M	3.5M	x 0.13
ivar_set.rb	26.6M	3.5M	x 0.13
loop_times.rb	26.7M	3.5M	x 0.13
loop_for.rb	26.8M	3.5M	x 0.13
loop_whileloop.rb	26.7M	3.5M	x 0.13
so_concatenate.rb	75.8M	27.3M	x 0.36
string_scan_str.rb	28.2M	5.7M	x 0.20
string_scan_re.rb	28.5M	5.5M	x 0.19
fiber_allocate.rb	209.7M	229.8M	x 1.10
fiber_switch.rb	26.7M	3.5M	x 0.13
so_mandelbrot.rb	27.2M	4.5M	x 0.16
app_mandelbrot.rb	27.1M	4.5M	x 0.16
app_fibo.rb	26.7M	3.5M	x 0.13
app_aobench.rb	27.3M	5.8M	x 0.21
so_nbody.rb	26.8M	3.7M	x 0.14
optcarrot	100.9M	65.2M	x 0.65
optcarrot --opt	117.2M	95.1M	x 0.81