Rack servers with up to 128 RISC-V modules and 1024 CPU cores

The Chinese brand Firefly is selling servers with 48 RISC-V modules, 384 CPU cores, and 768 GByte RAM starting at 34,150 Euros. Some details remain unclear.

Firefly CSC2-N48SPK3: Server in a rack chassis (2U) with 48 RISC-V processor modules

(Image: Firefly)

at 4:46 pm CEST

2 min. read

c't Magazin

By

Christof Windeck

Rack servers with up to 128 RISC-V modules and 1024 CPU cores

The Chinese brand Firefly offers, among other things, the CSC2-N48SPK3 rack server with 48 RISC-V computing modules in its online shop. Each of these is equipped with the eight-core SpacemiT K3 and 16 GByte LPDDR5 RAM.

In total, the CSC2-N48SPK3, available from 34,150 Euros, thus provides 384 CPU cores and 768 GByte RAM. A separate ARM board with Rockchip RK3588 is used for remote maintenance, which Firefly calls BMC.

For around 20,000 euros more, a version with twice the RAM is available. Firefly has also announced the “CSD2-N128 AI Server” with up to 128 computing modules, which can be equipped with ARM or RISC-V processors from Rockchip or SpacemiT.

Videos by heise

RISC-V chip with RVA23

The SpacemiT K3 is one of the first RISC-V processors to meet the requirements of the RVA23 specification. This, in turn, is the prerequisite for being able to install the RISC-V versions of current Linux distributions. SpacemiT cooperates with Canonical on Ubuntu 26.04 for the K3.

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RISC-V CPUs with RVA23: More performance and better Linux support

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Development board with the RVA23-compatible RISC-V SoC SpacemiT K3.

RISC-V single-board computer with RVA23 chip for new Linux distributions

Open questions

Four RJ45 sockets with 10 Gbit/s Ethernet are available for external communication. The remote maintenance module has a separate Gigabit Ethernet connection.

<div>System-on-Module Firefly CORE-K3JD4 with SpacemiT K3 RISC-V processor</div> — System-on-Module Firefly CORE-K3JD4 with SpacemiT K3 RISC-V processor

(Image: Firefly)

Firefly has not yet published how the 48 boards in the Firefly CSC2-N48SPK3 are connected to the four 10GE ports and the BMC. Firefly likely uses the onboard Ethernet adapters of the computing modules.

The functionality of the remote maintenance is also unclear. Unlike a typical “Baseboard Management Controller” (BMC), there is likely no separate remote maintenance chip on each individual module.

Firefly probably integrates 48 modules of its type CORE-K3JD4 into the CSC2-N48SPK3, which costs 325 euros each with a SpacemiT K3 and 16 GByte RAM. The module has the form factor of a notebook memory module (Small-Outline DIMM/SODIMM) with 260 contacts.

Already in business for a long time

Firefly, formerly also T-Firefly, is a brand of the Chinese company T-Chip Intelligent Technology from Zhongshan in Guangdong Province. Firefly sells numerous mini-computers, single-board computers, mainboards, and servers, many of them with ARM SoCs from the Chinese company Rockchip.