Announced back in June, AMD’s second-generation Threadripper processors are now available for preorder. The top-end part, the Threadripper 2990WX, is a 32-core, 64-thread processor with a total of 64MB of level 3 cache, running at a base clock of 3.0GHz, boosting as high as 4.2GHz. It ships on August 13 and is selling for $1,799.
|Model||Cores/Threads||Clock base/boost/GHz||Level 3 cache/MB||TDP/W||Price||Availability|
The basic building blocks of the second-generation Threadrippers are the same as the first-generation parts. Threadripper processors are multi-chip modules (MCMs) containing multiple dies and Infinity Fabric interconnects. AMD calls the basic building block of each chip a Core Complex (CCX), which has four cores, eight threads, and 8MB of level 3 cache. Each chip contains two CCXes. The first round of Threadrippers had four chips, with two of them active and two inactive, for a total of 16 cores and 32 threads. The new second-generation parts announced today make all four chips active, bringing the counts up to 32 cores and 64 threads.
The new chips increase the total power to 250W compared to 180W for the first-gen parts. However, AMD has said that the new processors will work in existing motherboards using the X399 chipset. Motherboards that can’t deliver substantially more than 180W will see limits to overclocking and turbo boosting, but they should nonetheless work correctly. New boards built for the second-gen parts should offer a bit more headroom.
The new processors use the revised Zen+ core of the Ryzen 2 processors. Improvements to the cache subsystem have reduced memory latencies and produce about 3 percent more instructions per cycle compared to the first-generation parts. The turbo boosting should also be smarter, able to push the processor closer to its thermal and power limits. The new chips are also built on a 12nm process (though they retain the same dimensions as their 14nm predecessors), enabling higher clock speeds and lower voltages.
One thing not changed is the allocation of memory controllers and PCIe lanes. In the first-generation parts, both of the functional chips contributed two memory channels and 32 PCIe links each. Even though the new Threadrippers include four functional chips instead of two, AMD has chosen to use the same arrangement in the new processors, meaning that the memory controllers and PCIe connections of two of the chips are unused. This has nuanced implications for optimal scheduling of running threads by the operating system, which should elect to use the cores with the memory controllers before using the cores without the memory controllers, as the former cores should be a little faster than the latter ones.
Benchmarks and reviews won’t be out until August 13, but AMD France did accidentally disclose a score for the Cinebench R15 rendering test—the 2990WX scored 5,099. This puts it comfortably ahead of Intel’s current top competing part, the $1,999, 18-core, 36-thread Core i9-7980XE, which scores about 3,300 points. Cinebench is one of the best-case workloads for these high thread-count processors, as it’s a workload that scales almost perfectly with the number of concurrent threads. It serves as a good indication of what Threadripper can achieve, provided you have a workload that can take advantage of this hardware.