AMD CDNA Architecture Based Arcturus GPU ‘Radeon Instinct’ Test Board Spotted – 120 CUs With 7680 Cores, 1200 MHz HBM2 Clock, 878 MHz GPU Clock

AMD's Radeon Instinct Arcturus GPU which will feature the CDNA architecture and aim the server market has been spotted by Rogame. Featured inside the next-generation Radeon Instinct graphics cards, the CDNA architecture will leverage its compute-optimized GPU design to deliver the highest performance Compute capabilities for data centers.

AMD's CDNA Architecture Based Arcturus GPU Test Board Leaks Out - Next-Gen Radeon Instinct With 120 CUs For A Total of 7680 Cores

The AMD Arcturus GPU leaked out all the way back in 2018 which was before AMD has introduced any 7nm GPU. The Radeon VII and Navi lineup launched in 2019 and featured 7nm GPUs with Navi being aimed at the mass consumer market.

It was later revealed that AMD's next-generation HPC & AI GPUs would be designed separately from the consumer-end chips. This meant that the Arcturus GPU would be kept exclusive to the datacenter market. AMD just recently confirmed in its Radeon CDNA architecture roadmap that all CDNA based GPUs would be exclusively designed for the HPC & data center markets while Radeon RDNA GPUs will power the consumer segment.

Coming to the specifications, it was previously unveiled that AMD's Arcturus GPU would feature an increased cache and double the CUs as Vega. That along with a list of data center specific features such as XDLOPs, Rapid Packed Math, New Vector ALU & BFloat16 are to be expected in the Radeon Instinct cards that feature the new CDNA architecture. The previous Radeon Instinct MI100 proto-type 'D34303' board featured the Arcturus-XL die with a rated TDP of 200W and 32 GB HBM2 VRAM clocked at around 1000-1200 MHz.

The information for this part is based on a prototype so it is likely that final specifications would not be the same but here are the key points:

• Based on Arcturus XL GPU
• Test Board has a TDP of 200W
• Up To 32 GB HBM2 Memory
• HBM2 Memory Clocks Reported Between 1000-1200 MHz

Once again, a test board has been spotted by Rogame which is based on the Arcturus CDNA GPU and from the looks of it, this variant offers 120 CUs for a total of 7680 stream processors & a GPU clock speed of 878 MHz (750 MHz SOC clock). This variant also features an undefined amount of HBM2 memory clocked at 1200 MHz so if we are looking at a 4096-bit bus, we should get around 1.2 TB/s bandwidth which is what Aquabolt is able to offer. But it is very likely that both NVIDIA & AMD would end up utilizing the faster HBM2E 'Flashbolt' standard which goes into production this year and will be capable of delivering up to 1.8 TB/s bandwidth.

Talking about the clock speeds, the 878 MHz for the test board are rather slow as we have seen variants going up to 1334 MHz in the past. At the mentioned speeds, the chip would boast around 13.5 TFLOPs of FP32 compute power which is lower than the Radeon Instinct MI60 and also the 21 TFLOPs that we got on the previous prototype sample. It is likely that the first iteration of CDNA GPUs would end up somewhere around 25 TFLOPs FP32.

I had to forget one important detail 😅

Arcturus (Test board)

> 120CU
> 878MHz Core clock
> 750Mhz SOC clock
> 1200MHz Memory clock

— _rogame 🇵🇸 (@_rogame) April 21, 2020

Based on leaks of Ampere GPUs which are also expected to be announced later this year, it looks like NVIDIA might hold the upper hand in terms of Compute performance as they are speculated to hit almost 36 TFLOPs of FP32 and 18 TFLOPs of FP64 Compute power with next-generation Tesla 7nm GPU lineup.

AMD Radeon Instinct Accelerators

Accelerator Name	AMD Instinct MI400	AMD Instinct MI350X	AMD Instinct MI300X	AMD Instinct MI300A	AMD Instinct MI250X	AMD Instinct MI250	AMD Instinct MI210	AMD Instinct MI100	AMD Radeon Instinct MI60	AMD Radeon Instinct MI50	AMD Radeon Instinct MI25	AMD Radeon Instinct MI8	AMD Radeon Instinct MI6
CPU Architecture	Zen 5 (Exascale APU)	N/A	N/A	Zen 4 (Exascale APU)	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
GPU Architecture	CDNA 4	CDNA 3+?	Aqua Vanjaram (CDNA 3)	Aqua Vanjaram (CDNA 3)	Aldebaran (CDNA 2)	Aldebaran (CDNA 2)	Aldebaran (CDNA 2)	Arcturus (CDNA 1)	Vega 20	Vega 20	Vega 10	Fiji XT	Polaris 10
GPU Process Node	4nm	4nm	5nm+6nm	5nm+6nm	6nm	6nm	6nm	7nm FinFET	7nm FinFET	7nm FinFET	14nm FinFET	28nm	14nm FinFET
GPU Chiplets	TBD	TBD	8 (MCM)	8 (MCM)	2 (MCM) 1 (Per Die)	2 (MCM) 1 (Per Die)	2 (MCM) 1 (Per Die)	1 (Monolithic)	1 (Monolithic)	1 (Monolithic)	1 (Monolithic)	1 (Monolithic)	1 (Monolithic)
GPU Cores	TBD	TBD	19,456	14,592	14,080	13,312	6656	7680	4096	3840	4096	4096	2304
GPU Clock Speed	TBD	TBD	2100 MHz	2100 MHz	1700 MHz	1700 MHz	1700 MHz	1500 MHz	1800 MHz	1725 MHz	1500 MHz	1000 MHz	1237 MHz
INT8 Compute	TBD	TBD	2614 TOPS	1961 TOPS	383 TOPs	362 TOPS	181 TOPS	92.3 TOPS	N/A	N/A	N/A	N/A	N/A
FP16 Compute	TBD	TBD	1.3 PFLOPs	980.6 TFLOPs	383 TFLOPs	362 TFLOPs	181 TFLOPs	185 TFLOPs	29.5 TFLOPs	26.5 TFLOPs	24.6 TFLOPs	8.2 TFLOPs	5.7 TFLOPs
FP32 Compute	TBD	TBD	163.4 TFLOPs	122.6 TFLOPs	95.7 TFLOPs	90.5 TFLOPs	45.3 TFLOPs	23.1 TFLOPs	14.7 TFLOPs	13.3 TFLOPs	12.3 TFLOPs	8.2 TFLOPs	5.7 TFLOPs
FP64 Compute	TBD	TBD	81.7 TFLOPs	61.3 TFLOPs	47.9 TFLOPs	45.3 TFLOPs	22.6 TFLOPs	11.5 TFLOPs	7.4 TFLOPs	6.6 TFLOPs	768 GFLOPs	512 GFLOPs	384 GFLOPs
VRAM	TBD	HBM3e	192 GB HBM3	128 GB HBM3	128 GB HBM2e	128 GB HBM2e	64 GB HBM2e	32 GB HBM2	32 GB HBM2	16 GB HBM2	16 GB HBM2	4 GB HBM1	16 GB GDDR5
Infinity Cache	TBD	TBD	256 MB	256 MB	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Memory Clock	TBD	TBD	5.2 Gbps	5.2 Gbps	3.2 Gbps	3.2 Gbps	3.2 Gbps	1200 MHz	1000 MHz	1000 MHz	945 MHz	500 MHz	1750 MHz
Memory Bus	TBD	TBD	8192-bit	8192-bit	8192-bit	8192-bit	4096-bit	4096-bit bus	4096-bit bus	4096-bit bus	2048-bit bus	4096-bit bus	256-bit bus
Memory Bandwidth	TBD	TBD	5.3 TB/s	5.3 TB/s	3.2 TB/s	3.2 TB/s	1.6 TB/s	1.23 TB/s	1 TB/s	1 TB/s	484 GB/s	512 GB/s	224 GB/s
Form Factor	TBD	TBD	OAM	APU SH5 Socket	OAM	OAM	Dual Slot Card	Dual Slot, Full Length	Dual Slot, Full Length	Dual Slot, Full Length	Dual Slot, Full Length	Dual Slot, Half Length	Single Slot, Full Length
Cooling	TBD	TBD	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling	Passive Cooling
TDP (Max)	TBD	TBD	750W	760W	560W	500W	300W	300W	300W	300W	300W	175W	150W

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So far, AMD has unveiled that the main focus of CDNA would be performance, efficiency, features, scalability in the data center market. Currently, AMD's GCN architecture has served this segment but with CDNA, AMD will be creating GPUs specifically optimized for high-performance Compute, Machine Learning, and HPC. The 1st Gen CDNA GPUs will feature a 2nd Gen Infinity Architecture and would utilize the ROCm (Radeon Open Compute Platform) to power the data center with key optimizations and enhanced scalability. The 2nd Gen Infinity Architecture will allow for 4-8 Way GPU connectivity in a singular node, allowing the new Radeon Instinct boards to run in harmony.

AMD has proved that they can offer more FLOPs at a competitive price so maybe that is where Arcturus would be targetting. There's no word on when Arcturus would land, but AMD has hinted at a Radeon Instinct product later this year which will feature its 1st Gen CDNA architecture.

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