I did the same thing, we take advantage of the calm to put things in order and improve the details.
For my part I dropped the timer because the loading time of the home page varies greatly depending on the data it displays. For example, a post in the feed with embedly takes time. Also depends on the pictures posted etc ... So I'm just based on my feelings.
There is a moment that I try to run php5 and php7 simultaneously on the same server, the reason is that I have a Dolphin site and even if the kernel and boonex modules have been updated for php7, the modules third parties did not follow.
Finally I got to know php-fpm because it is a good solution to run several versions simultaneously. Unfortunately I lost a lot of time doing tests with php7.2-fpm with which I got results much slower than php5.6 against any logic. Finally, it seems that 7.2-fpm + relates to a problem with SQL queries. Which forced me to install 7.1 in the end.
So I would just say this. On the same server, so I left php5.6 + apache, which gave me a speed that I would qualify as acceptable without being exceptional. Then I went to php5.6-fpm. Already nothing that is a huge gain, I would say load time largely divided by two. Then I switched to php7.1-fpm, still on the same machine and there I would say loading time still divided by 3. Of course like Cem, I also refined the config of mysql, opcache and fpm.
Well I would say that now it is moving and what is fantastic compared to my old basic config is that now I can load the page with a lot of content and queries, we do not feel the difference. Before I had to be very careful. The difference is incredible!
Cpu: 1 x i7
Ram: 24 Gb

No SSD

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OpCache

opcache.enable = 1

opcache.interned_strings_buffer = 32

opcache.max_accelerated_files = 100000

opcache.max_wasted_percentage = 15

opcache.validate_timestamps = 1

opcache.revalidate_freq = 1

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Mysql

key_buffer_size         = 64M
max_allowed_packet      = 16M
thread_stack            = 192K
thread_cache_size       = 192
max_connections        = 250
table_open_cache        = 100000
max_heap_table_size     = 128M
tmp_table_size          = 1024M
innodb_buffer_pool_size = 10GB
query_cache_limit       = 2M
query_cache_size        = 32M

---------------------------------------

PHP

memory_limit = 1024M

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Pool

pm = dynamic
pm.max_children = 20
pm.start_servers = 7
pm.min_spare_servers = 7
pm.max_spare_servers = 15
pm.max_requests = 500

---------------------------------

Do you think that ssd can still improve? I may be testing soon...