THREADRIPPER 3990X ISSUES

The AMD Threadripper 3990X has 64 cores and 128 threads. This is AMD’s flagship professional CPU. The CPU should be generally available in 30 to 60 days.

This processor has revealed that Microsoft a long time ago designed the operating system with less cores in mind. Microsoft is also very aware of Amdahl’s Law governing parallel programming. Unfortunately the majority of software is designed as a single thread.

Dual socket machines have been around since at least the 80386. Microsoft has 2 main versions, Windows 10 home and Windows 10 professional. Windows professional allows dual socket machines to be used.

Dual socket motherboards are about double the cost of gaming motherboards and they generally need a larger EATX chassis like the HAF 932. AMD and Intel processors for dual socket machines can be quite expensive too. RAM has to be acquired in large trays to accommodate the 16 slots seen on dual socket motherboards.

Windows Server has no limitations on the number of sockets as corporate machines with 4 processors are common. HP has even offered 8 socket servers. Most blade servers however tend to be dual CPU designs with large amounts of RAM to handle virtual machines. The M.2 SSD fits the blade motherboard easily making blade servers very popular with Azure and their competitors.

The Windows 10 task scheduler was designed to handle a maximum of 64 threads. This is where the new 3990X exceeds that design limitation. Now the AMD 3990X with 64 cores and 128 threads is pushing Windows 10 professional to its limits.

With more than 64 cores, Windows creates groups and the 3990X becomes a dual group unit and the task manager shows this as dual socket even though the CPU is not. This is due to the task scheduler limitations.

Microsoft has a new version of Windows 10 Pro for Workstations which is available for the RTX40 platform with the 64 core and 128 thread design. There is also Windows 10 Enterprise which is often used by governments and large corporations. Windows 10 professional can support up to 2TB of RAM and Windows Enterprise can support up to 6TB of memory.

The TR40 has 8 memory slots so it costs more to load it up compared to the AM4 platform. 8x8GB will be about $350 at current prices. Double that for 8x16GB.