Intel Discloses 8 Core & 528 Thread CPU Based on RISC Architecture, 66 Threads Per Core

During Hot Chips 2023, Intel showed off a brand new CPU design featuring 8 cores but a massive 528 threads based on RISC.

The motivations that led Intel to create such a unique chip design are based on some specific work-loads that not only require insane parallel compute capabilities but also lead to under-utilization of the available hardware, most importantly the cache. One such workload is Graph Analytics such as DARPA's HIVE program which is a petabyte-scale graph analytics workload and offers 1000x Perf/W when compared to traditional compute.

For similar workloads, Intel has devised a new CPU with 8 cores and 528 threads. Yes, that's a total of 66 threads per core with 192 KB cache per core and 4 MB SRAM. The CPU is based on the RISC architecture and not x86 but makes use of silicon photonics for networking. The CPU will come in a chipset-esque design featuring EMIB interconnect to connect the optical chips to the main CPU die.

Taking a closer look, this CPU design from Intel comes with 16 Multi-Threaded Pipelines (MTP) while the Single-Threaded Pipelines (STP) offer 8x higher single-threaded performance. The architecture, as stated above, is based on a custom RISC design featuring 32 registers per thread. The chip also supports a custom DDR5 memory controller, allowing for up to DDR5-4400 DIMMs with 8B access granularity, 32 High-Speed AIB ports, and PCIe Gen4 x8 protocol.

Following is the die breakdown:

TSMC 7nm FinFET Process Node

Interconnect: 15 Metal Layers

27.6 Billion Transistors (Total)

1.2 Billion Transistors (CPU Core)

316mm2 Die Area (Total)

9.2mm2 Per Core Area

705 Signals

3275 BGA Form Factor

Coming to the networking capabilities that make use of the aforementioned Silicon Photonics, Intel has laid out a 2D on-de mesh interconnect that uses 16 routers. The cores can talk to others off or on the system without the need to add other networking capabilities.

The socket (BGA-3275) will support 32 optical I/O ports at 32 GB/s/dir and 32 GB of custom DDR5-4400 DRAM. The platform will extend support to 16 sockets in an OCP sled form factor so that's 120 cores and 8448 threads on the top-most configuration. The platform will also support up to 512 GB DRAM.

A demo shown off by Intel details the power and clock speeds (Fmax) of the CPU. This particular 8 Core SKU has a 75W TDP and has the majority of its power budget being used by Photonics while the cores themselves take up 21% of the power budget or around 16W. The chip is said to balance out around 3.35-3.5 GHz with 35-55W power. The company claims to get linear performance as the core count is increased by 10 fold.

News Source: ServerTheHome