But any way i can prove speed in easy way

You can make private in range
from
0x0000000000000000000000000000000000000000000000000000000000000001
to
0x00000000000000000000000000000000000000000000000031f5c4ed27680000
than make public key(64bytes) from this private key and show me this public key.
Total points in this range 3600000000000000000, so i will limit speed to 1Ph/s and i my CPU should brute-force this range in 1hour.
That isn't impressive at all. Because you fix a range, you could simply have a table of 2^32 entries and find the match in one hour at a terribly slow rate of 1.2 million keys a second.
Go away scammer.