It has taken a few years worth of reading, testing settings, and getting over my ego to find the ideal speed and stability of my rig. But one of the biggest things I have figured out along the way is that, regardless of tested stability of any memory speeds, you should NEVER set your memory above the specified Memory Bandwidth of the CPU unless you want some bottlenecking from your Memory Controller. And all of AMD FX-series CPUs have a Memory Bandwidth of 29.9GB/s, so...
29.9GB/s = 30,617.6MB/s
30,617.6 / 32 = 956.8MHz (DDR)
What this means is that the Max Memory Speed on all AMD FX-series CPUs is DDR3-1913.6, which is why they have a specified Native Memory Speed of 1866MHz. So, even if you have DDR3-2400 or higher memory, and it's supported by your motherboard, always remember to consider the actual bandwidth of the Memory Controller on the CPU--or the Motherboard for older systems. After figuring this out and tweaking my rig, I finally have MUCH smoother performance all-around. Here's my specs and setup...
MY RIG:
ASUS Crosshair V Formula-Z (AMD 990FX; SB950)
AMD FX-9590 Black Edition (Vishera; 8-Core; 220W) @ 4720MHz
AMD Radeon R9 Gamer Series 16GB (2x8GB) PC3-19200/DDR3-2400 @ 1800 [8-10-10-24 1T]
EVGA Geforce GTX 1080 Ti SC2 11GB GDDR5X
Creative Sound Blaster X-FI Titanium Fata1ity Professional 64MB X-RAM
(2) Seagate IronWolf Pro 2TB (128MB Cache; 7200RPM; SATA 6.0Gb/s)
Frequencies:
CPU Bus Frequency: 224MHz (~224.75MHz in OS)
CPU Multiplier: 21x (4720MHz)
CPU/NB Multiplier: 12x (2697MHz)
HTT Multiplier: 12x (2697MHz)
Memory Multiplier: 8x (1798MHz)
Voltages:
CPU Voltage: 1.425v
CPU/NB Voltage: 1.325v
DRAM Voltage: 1.665v
NB HT Voltage: 1.25v
Power:
CPU Load Line Calibration: ULTRA HIGH
CPU Current Capability: DISABLED
CPU Power Phase Control: EXTREME
CPU Power Switching Frequency: MANUAL
VRM Fixed Frequency Mode: 550KHz
CPU Power Duty Control: EXTREME
CPU Power Response Control: ULTRA FAST
CPU Power Thermal Control: 151
CPU/NB Load Line Calibration: REGULAR
CPU/NB Current Capability: 130%
CPU/NB Power Response Control: ULTRA FAST
DRAM Current Capability: 130%
DRAM Power Phase Control: EXTREME
DRAM Power Switching Frequency: 500KHz
I did a little further testing since my previous post and found an even sweeter spot with faster response and smoother gameplay...
MY RIG:
ASUS Crosshair V Formula-Z (AMD 990FX; SB950)
AMD FX-9590 Black Edition (Vishera; 8-Core; 220W) @ 4792MHz
AMD Radeon R9 Gamer Series 16GB (2x8GB) PC3-19200/DDR3-2400 @ 1864 [9-10-10-24 1T]
EVGA Geforce GTX 1080 Ti SC2 11GB GDDR5X
Creative Sound Blaster X-FI Titanium Fata1ity Professional 64MB X-RAM
(2) Seagate IronWolf Pro 2TB (128MB Cache; 7200RPM; SATA 6.0Gb/s)
Frequencies:
CPU Bus Frequency: 199MHz (~199.66MHz in OS)
CPU Multiplier: 24x (4792MHz)
CPU/NB Multiplier: 11x (2196MHz)
HTT Multiplier: 13x (2596MHz)
Memory Multiplier: 9.33x (1864MHz)
Voltages:
CPU Voltage: 1.43125v (1.428-1.456v)
CPU/NB Voltage: 1.20v (1.204-1.25v)
DRAM Voltage: 1.655v (1.647-1.654v)
NB HT Voltage: 1.20v (1.217v)
Power:
CPU Load Line Calibration: ULTRA HIGH
CPU Current Capability: DISABLED
CPU Power Phase Control: EXTREME
CPU Power Switching Frequency: MANUAL
VRM Fixed Frequency Mode: 550KHz
CPU Power Duty Control: EXTREME
CPU Power Response Control: ULTRA FAST
CPU Power Thermal Control: 151
CPU/NB Load Line Calibration: REGULAR
CPU/NB Current Capability: 130%
CPU/NB Power Response Control: ULTRA FAST
DRAM Current Capability: 130%
DRAM Power Phase Control: EXTREME
DRAM Power Switching Frequency: 500KHz