Vera does what NVIDIA calls Spatial Multithreading, "physically partitioning each core’s resources rather than time slicing them, allowing the system to optimize for performance or density at runtime." A kind of static hyperthreading; you get two threads per core.
It's somewhat different from how x86 chips do simultaneous multithreading (SMT),
Seems like curious terminology from NV. In estabilished use, SMT means executing instructions from several cpu threads concurrently in the OOO CPU's execution units so they are not starved from work, whereas timeslicing conventionally means context switching between threads/processes, alternating temporally.
In operating systems timeslicing means giving a quantum of execution time to each process, and context switching between processes. Not normally a term used in computer architecture but possibly the characterisation would fit a barrer processor rather than SMT.
I own one of these systems. My interpretation is the Ampere systems are targeted at lower cost scale out. The Ampere Altra CPUs are limited to DDR4. The raw single core performance doesn’t match Intel or AMD offerings. You get a lot of cores for a lower hardware cost and at lower energy usage.
The Nvidia CPUs are designed for a very specific use case. They are designed for high performance with less concern about cost control.
The newer AmpereOne CPUs use DDR5 with the AmpereOne M supporting even higher memory bandwidth. Even then, I doubt the AmpereOne CPUs will match the performance of the Nvidia Rubin CPUs. But the Ampere processors are available for general use. I am guessing that Nvidia is only going to sell the complete rack system and only to high-volume customers.
Vera does what NVIDIA calls Spatial Multithreading, "physically partitioning each core’s resources rather than time slicing them, allowing the system to optimize for performance or density at runtime." A kind of static hyperthreading; you get two threads per core.
It's somewhat different from how x86 chips do simultaneous multithreading (SMT),
Seems like curious terminology from NV. In estabilished use, SMT means executing instructions from several cpu threads concurrently in the OOO CPU's execution units so they are not starved from work, whereas timeslicing conventionally means context switching between threads/processes, alternating temporally.
In operating systems timeslicing means giving a quantum of execution time to each process, and context switching between processes. Not normally a term used in computer architecture but possibly the characterisation would fit a barrer processor rather than SMT.
Hmm, the 128-core Ampere Altra CPU is already available, and in a case from System76. I wonder what else differentiates it.
If they're going to build CPUs I wish they had used Risc-V instead. They are using it somewhat already.
You can see here[1] what the specs are for the CPU (listed as "NVIDIA Vera Rubin Superchip").
The CPU is integrated with two Rubin GPUs but each of the CPU cores has dedicated FP8 acceleration as well.
1. https://www.nvidia.com/en-us/data-center/vera-rubin-nvl72/
I own one of these systems. My interpretation is the Ampere systems are targeted at lower cost scale out. The Ampere Altra CPUs are limited to DDR4. The raw single core performance doesn’t match Intel or AMD offerings. You get a lot of cores for a lower hardware cost and at lower energy usage.
The Nvidia CPUs are designed for a very specific use case. They are designed for high performance with less concern about cost control.
The newer AmpereOne CPUs use DDR5 with the AmpereOne M supporting even higher memory bandwidth. Even then, I doubt the AmpereOne CPUs will match the performance of the Nvidia Rubin CPUs. But the Ampere processors are available for general use. I am guessing that Nvidia is only going to sell the complete rack system and only to high-volume customers.