I would also check CPU, disk, and memory utilization.
ByteCheck shows a much better percentage (~60% which is rather normal)
If all else fails, you could try switching the RSA 2048 bit cert for an ECDSA 256 bit cert.
To see how the CPU and ciphers perform on your system, try:
This test result is rather low:
openssl s_time -connect www.snowcrows.com:443
No CIPHER specified
Collecting connection statistics for 30 seconds
82 connections in 1.09s; 75.09 connections/user sec, bytes read 0
82 connections in 31 real seconds, 0 bytes read per connection
Now timing with session id reuse.
135 connections in 0.08s; 1730.76 connections/user sec, bytes read 0
135 connections in 31 real seconds, 0 bytes read per connection
Try this command locally, see if the numbers are higher:
openssl s_time -connect localhost:443
NOTE: some versions of openssl require specified cipher, if so, use your site preferred