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AMD EPYC 9556 vs AMD EPYC 9966: Comparison
EPYC 9556 vs EPYC 9966 l3 cache compared
On l3 cache the spread is 50%, EPYC 9556 384 MB against EPYC 9966 768 MB, so EPYC 9966 takes it. Boost clock is not the same on both, 4.3 GHz on the EPYC 9556 versus 4 GHz on the EPYC 9966. Tdp is not the same on both, 300 W on the EPYC 9556 versus 600 W on the EPYC 9966. They differ on configurable tdp max too, 300 W on the EPYC 9556 versus 600 W on the EPYC 9966. Core count is not the same on both, 64 cores on the EPYC 9556 versus 192 cores on the EPYC 9966. They differ on thread count too, 128 threads on the EPYC 9556 versus 384 threads on the EPYC 9966. They differ on base clock too, 2.75 GHz on the EPYC 9556 versus 2.9 GHz on the EPYC 9966. There is a split on launch price as well, $8,008 on the EPYC 9556 versus $14,079 on the EPYC 9966.
EPYC 9556 vs EPYC 9966: which one fits your build
Buy the EPYC 9556 for datacenter and cloud compute and virtualization-dense server workloads, though it is the wrong buy for consumer desktop builds and single-threaded latency-sensitive workloads on lower core-count SKUs. The EPYC 9966 is the one to take for datacenter and cloud compute and virtualization-dense server workloads, though it is not built for consumer desktop builds and single-threaded latency-sensitive workloads on lower core-count SKUs.
Where the two are identical
The common ground is wider than the gap: memory channels, pcie lanes, cpu socket, product family and segment are identical here. They match on 10 further specifications as well.
Frequently asked questions
Is the SMT Support the same on the EPYC 9556 and EPYC 9966?
It is. Both are listed at Yes, so it is not a reason to pick one over the other.
Specs and benchmarks
Brand
- AMD EPYC 9556
- AMD
- AMD EPYC 9966
- AMD
Model Number
- AMD EPYC 9556
- 9556
- AMD EPYC 9966
- 9966
CPU Socket
- AMD EPYC 9556
- SP7
- AMD EPYC 9966
- SP7
Product Family
- AMD EPYC 9556
- EPYC 9006 Series
- AMD EPYC 9966
- EPYC 9006 Series
Segment
- AMD EPYC 9556
- Data Center
- AMD EPYC 9966
- Data Center
Core Count
- AMD EPYC 9556
- 64 cores
- AMD EPYC 9966
- 192 cores
Thread Count
- AMD EPYC 9556
- 128 threads
- AMD EPYC 9966
- 384 threads
SMT Support
- AMD EPYC 9556
- Yes
- AMD EPYC 9966
- Yes
Base Clock
- AMD EPYC 9556
- 2.75 GHz
- AMD EPYC 9966
- 2.9 GHz
Boost Clock
- AMD EPYC 9556
- 4.3 GHz
- AMD EPYC 9966
- 4 GHz
L3 Cache
- AMD EPYC 9556
- 384 MB-50%
- AMD EPYC 9966
- 768 MBBest
Socket
- AMD EPYC 9556
- SP7
- AMD EPYC 9966
- SP7
Multi-Socket Support
- AMD EPYC 9556
- Dual Socket
- AMD EPYC 9966
- Dual Socket
Memory Channels
- AMD EPYC 9556
- 16 channels
- AMD EPYC 9966
- 16 channels
Memory Type
- AMD EPYC 9556
- DDR5 RDIMM
- AMD EPYC 9966
- DDR5 RDIMM
Max Memory Speed
- AMD EPYC 9556
- 8000 MT/s
- AMD EPYC 9966
- 8000 MT/s
Registered Memory Required
- AMD EPYC 9556
- Yes
- AMD EPYC 9966
- Yes
PCIe Lanes
- AMD EPYC 9556
- 96 lanes
- AMD EPYC 9966
- 96 lanes
PCIe Generation
- AMD EPYC 9556
- PCIe 6.0
- AMD EPYC 9966
- PCIe 6.0
TDP
- AMD EPYC 9556
- 300 W
- AMD EPYC 9966
- 600 W
Configurable TDP Max
- AMD EPYC 9556
- 300 W
- AMD EPYC 9966
- 600 W
Launch Price
- AMD EPYC 9556
- $8,008
- AMD EPYC 9966
- $14,079
Memory Bandwidth
- AMD EPYC 9556
- 1024 GB/s / 1638 GB/s
- AMD EPYC 9966
- 1024 GB/s / 1638 GB/s
PCIe
- AMD EPYC 9556
- PCIe 6.0 x96
- AMD EPYC 9966
- PCIe 6.0 x96
Memory Support
- AMD EPYC 9556
- DDR5 RDIMM | MRDIMM, 16-Channel, Up to 8000 MT/s / Up to 12800 MT/s
- AMD EPYC 9966
- DDR5 RDIMM | MRDIMM, 16-Channel, Up to 8000 MT/s / Up to 12800 MT/s
Which one should you pick?
Choose 9556 if you want the higher memory channels (16 channels vs 16 channels) and the higher PCIe lanes (96 lanes vs 96 lanes).
Choose 9966 if you want the higher L3 cache (768 MB vs 384 MB).