Intel Core i7 Processor CPU has 4 physical cores, instead of 8 cores.
Due to Intel HT (Hyper-Threading Technology), it can Multi-threading.
when [Enabled] Intel HT Technology in BIOS (Default Value),
Enter into OS, can see processor thread running with [8 cores].
If [Disabled] Intel HT Technology in BIOS manually.
Enter into OS, can see processor thread running with [4 cores].