I installed the 64 bit 2.8.8 version of Thetis on a core 2 duo laptop. Processor is T6670 @ 2.2 GHz. Win10 Pro 64bit vers 2004. 8GB ram installed.
When trying to launch, it fails at port audio initialization. 32 bit version is fine.
I did a "coreinfo" dump and it says AVX is supported.
C:\Coreinfo>coreinfo64
Coreinfo v3.5 - Dump information on system CPU and memory topology
Copyright (C) 2008-2020 Mark Russinovich
Sysinternals - 
www.sysinternals.com
Intel(R) Core(TM)2 Duo CPU     T6670  @ 2.20GHz
Intel64 Family 6 Model 23 Stepping 10, GenuineIntel
Microcode signature: 00000A0C
HTT             *       Hyperthreading enabled
HYPERVISOR      -       Hypervisor is present
VMX             *       Supports Intel hardware-assisted virtualization
SVM             -       Supports AMD hardware-assisted virtualization
X64             *       Supports 64-bit mode
SMX             -       Supports Intel trusted execution
SKINIT          -       Supports AMD SKINIT
NX              *       Supports no-execute page protection
SMEP            -       Supports Supervisor Mode Execution Prevention
SMAP            -       Supports Supervisor Mode Access Prevention
PAGE1GB         -       Supports 1 GB large pages
PAE             *       Supports > 32-bit physical addresses
PAT             *       Supports Page Attribute Table
PSE             *       Supports 4 MB pages
PSE36           *       Supports > 32-bit address 4 MB pages
PGE             *       Supports global bit in page tables
SS              *       Supports bus snooping for cache operations
VME             *       Supports Virtual-8086 mode
RDWRFSGSBASE    -       Supports direct GS/FS base access
FPU             *       Implements i387 floating point instructions
MMX             *       Supports MMX instruction set
MMXEXT          -       Implements AMD MMX extensions
3DNOW           -       Supports 3DNow! instructions
3DNOWEXT        -       Supports 3DNow! extension instructions
SSE             *       Supports Streaming SIMD Extensions
SSE2            *       Supports Streaming SIMD Extensions 2
SSE3            *       Supports Streaming SIMD Extensions 3
SSSE3           *       Supports Supplemental SIMD Extensions 3
SSE4a           -       Supports Streaming SIMDR Extensions 4a
SSE4.1          *       Supports Streaming SIMD Extensions 4.1
SSE4.2          -       Supports Streaming SIMD Extensions 4.2
AES             -       Supports AES extensions
AVX             -       Supports AVX instruction extensions
FMA             -       Supports FMA extensions using YMM state
MSR             *       Implements RDMSR/WRMSR instructions
MTRR            *       Supports Memory Type Range Registers
XSAVE           *       Supports XSAVE/XRSTOR instructions
OSXSAVE         *       Supports XSETBV/XGETBV instructions
RDRAND          -       Supports RDRAND instruction
RDSEED          -       Supports RDSEED instruction
CMOV            *       Supports CMOVcc instruction
CLFSH           *       Supports CLFLUSH instruction
CX8             *       Supports compare and exchange 8-byte instructions
CX16            *       Supports CMPXCHG16B instruction
BMI1            -       Supports bit manipulation extensions 1
BMI2            -       Supports bit manipulation extensions 2
ADX             -       Supports ADCX/ADOX instructions
DCA             -       Supports prefetch from memory-mapped device
F16C            -       Supports half-precision instruction
FXSR            *       Supports FXSAVE/FXSTOR instructions
FFXSR           -       Supports optimized FXSAVE/FSRSTOR instruction
MONITOR         *       Supports MONITOR and MWAIT instructions
MOVBE           -       Supports MOVBE instruction
ERMSB           -       Supports Enhanced REP MOVSB/STOSB
PCLMULDQ        -       Supports PCLMULDQ instruction
POPCNT          -       Supports POPCNT instruction
LZCNT           -       Supports LZCNT instruction
SEP             *       Supports fast system call instructions
LAHF-SAHF       *       Supports LAHF/SAHF instructions in 64-bit mode
HLE             -       Supports Hardware Lock Elision instructions
RTM             -       Supports Restricted Transactional Memory instructions
DE              *       Supports I/O breakpoints including CR4.DE
DTES64          *       Can write history of 64-bit branch addresses
DS              *       Implements memory-resident debug buffer
DS-CPL          *       Supports Debug Store feature with CPL
PCID            -       Supports PCIDs and settable CR4.PCIDE
INVPCID         -       Supports INVPCID instruction
PDCM            *       Supports Performance Capabilities MSR
RDTSCP          -       Supports RDTSCP instruction
TSC             *       Supports RDTSC instruction
TSC-DEADLINE    -       Local APIC supports one-shot deadline timer
TSC-INVARIANT   -       TSC runs at constant rate
xTPR            *       Supports disabling task priority messages
EIST            *       Supports Enhanced Intel Speedstep
ACPI            *       Implements MSR for power management
TM              *       Implements thermal monitor circuitry
TM2             *       Implements Thermal Monitor 2 control
APIC            *       Implements software-accessible local APIC
x2APIC          -       Supports x2APIC
CNXT-ID         -       L1 data cache mode adaptive or BIOS
MCE             *       Supports Machine Check, INT18 and CR4.MCE
MCA             *       Implements Machine Check Architecture
PBE             *       Supports use of FERR#/PBE# pin
PSN             -       Implements 96-bit processor serial number
PREFETCHW       *       Supports PREFETCHW instruction
Maximum implemented CPUID leaves: 0000000D (Basic), 80000008 (Extended).
Maximum implemented address width: 48 bits (virtual), 36 bits (physical).
Processor signature: 0001067A
Logical to Physical Processor Map:
*-  Physical Processor 0
-*  Physical Processor 1
Logical Processor to Socket Map:
**  Socket 0
Logical Processor to NUMA Node Map:
**  NUMA Node 0
No NUMA nodes.
Logical Processor to Cache Map:
*-  Data Cache          0, Level 1,   32 KB, Assoc   8, LineSize  64
*-  Instruction Cache   0, Level 1,   32 KB, Assoc   8, LineSize  64
**  Unified Cache       0, Level 2,    2 MB, Assoc   8, LineSize  64
-*  Data Cache          1, Level 1,   32 KB, Assoc   8, LineSize  64
-*  Instruction Cache   1, Level 1,   32 KB, Assoc   8, LineSize  64
Logical Processor to Group Map:
**  Group 0
Mike, N1JEZ