Stable sleep configuration, cpus=8

Hardware:
MacPro5,1
Dual Xeon E5520 2.26 GHz physically installed
16 GB RAM
RX 580 8 GB

Active CPU state:
hw.packages: 1
hw.physicalcpu: 4
hw.logicalcpu: 8
machdep.cpu.brand_string: Intel(R) Xeon(R) CPU E5520 @ 2.27GHz
machdep.cpu.core_count: 4
machdep.cpu.thread_count: 8

Boot arguments:
keepsyms=1 debug=0x100 -lilubetaall -btlfxallowanyaddr ipc_control_port_options=0 -nokcmismatchpanic cpus=8

Power settings:
hibernatemode 0

Loaded CPU and platform components:
CPUFriend 1.2.9
AppleIntelCPUPowerManagement 222.0.0
AppleIntelCPUPowerManagementClient 222.0.0
IOPlatformPluginFamily 6.0.0d8
IOPlatformPluginLegacy 1.0.0
ACPI_SMC_PlatformPlugin 1.0.0

Result:
Normal sleep and wake are stable with cpus=8.