Update from 2022:

Device for benchmark:
* MacBook Pro (16 Zoll, 2019)
  * 2,6 GHz 6-Core Intel Core i7
  * 16 GB 2667 MHz DDR4

```bash
openssl version:
LibreSSL 2.8.3
```

Running the same command as before ..
```bash
openssl speed rsa2048 rsa4096
```

.. leads to:
```bash
                  sign    verify    sign/s verify/s
rsa 2048 bits 0.000891s 0.000049s   1122.1  20270.8
rsa 4096 bits 0.006737s 0.000174s    148.4   5741.9
```

I know the numbers are barely camparable.
Nevertheless we are searching for the factor the calculationtime jumps by switching from 2048 to 4096.

Hence, comparing the 'sing/s' of 2048 and 4096:
```bash
 Year      Person    2048      4096     CTR*
------------------------------------------------
 2016      tom       1459.1    132.0    11.05
 2016      user       501.5     69.3     7.2367
 2022      me        1122.1    148.4     7.5613
------------------------------------------------
 avg       of 3      1027.57   116,57    8.8153
```
*CTR = Calculation Time Raise (2048/4096)

**Doubling the bits of the RSA-key (2048 -> 4096 = Factor 2), the calculation time raises by more than a factor of 7**