Apache and PHP-FPM with MPM Event

Hi all I'm after some advice tuning Apache and PHP-FPM while using Event MPM module. Most guides I've read are assuming MPM Prefork, but there does appear to be some differences and are often contradictory. I've tried following a number and have produced the following settings: Apache Global Config

• Start Servers: 3
• Min Spare Servers: 3
• Max Spare Servers: 16
• Server Limit: 16
• Max Request Workers: 400
• Max Connections per Child: 10000
• Keep -Alive: on
• Keep-Alive Timeout: 5
• Max Keep-Alive Request: Unlimited
• Timeout: 60

PHP-FPM

• Max Request: 20
• Max Children: 15
• Process Idle Timeout: 10

Server Usage The server is primarily used to host WordPress sites. Current count is about 90sites, majority low traffic. A number have PHP-FPM enabled, but not all at this point. Server Spec Server is 16 Core and 16 GB RAM. "/proc/cpuinfo" produces the following info... processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 2 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 3 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 4 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 5 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 6 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 8 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 9 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 10 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 11 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 12 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 13 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 14 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 15 vendor_id : GenuineIntel cpu family : 6 model : 63 model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz stepping : 2 microcode : 0x43 cpu MHz : 2299.998 cache size : 25600 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae mce cx8 sep mca cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm intel_ppin ssbd ibrs ibpb stibp fsgsbase bmi1 avx2 bmi2 erms xsaveopt spec_ctrl intel_stibp bogomips : 4599.99 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management:
Any advice would be an immense help. Thanks.