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AMD EPYC 9256 vs AMD EPYC 9646: Comparison
What is the difference between EPYC 9256 and EPYC 9646?
On l3 cache the spread is 63%, EPYC 9256 96 MB against EPYC 9646 256 MB, so EPYC 9646 takes it. There is a split on boost clock as well, 4.5 GHz on the EPYC 9256 versus 3.7 GHz on the EPYC 9646. There is a split on tdp as well, 190 W on the EPYC 9256 versus 300 W on the EPYC 9646. Configurable tdp max is not the same on both, 220 W on the EPYC 9256 versus 300 W on the EPYC 9646. Core count is not the same on both, 24 cores on the EPYC 9256 versus 96 cores on the EPYC 9646. They differ on thread count too, 48 threads on the EPYC 9256 versus 192 threads on the EPYC 9646. They differ on base clock too, 2.85 GHz on the EPYC 9256 versus 2.8 GHz on the EPYC 9646.
Who each one is for
Buy the EPYC 9256 for datacenter and cloud compute and virtualization-dense server workloads, though it is not the pick for consumer desktop builds and single-threaded latency-sensitive workloads on lower core-count SKUs. The EPYC 9646 is the one to take 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.
Where the two are identical
Where they agree, they agree completely, memory channels, pcie lanes, cpu socket, product family and segment included, so the decision does not turn on any of those. They match on 10 further specifications as well.
Frequently asked questions
Is the SMT Support the same on the EPYC 9256 and EPYC 9646?
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 9256
- AMD
- AMD EPYC 9646
- AMD
Model Number
- AMD EPYC 9256
- 9256
- AMD EPYC 9646
- 9646
CPU Socket
- AMD EPYC 9256
- SP8
- AMD EPYC 9646
- SP8
Product Family
- AMD EPYC 9256
- EPYC 9006 Series
- AMD EPYC 9646
- EPYC 9006 Series
Segment
- AMD EPYC 9256
- Data Center
- AMD EPYC 9646
- Data Center
Core Count
- AMD EPYC 9256
- 24 cores
- AMD EPYC 9646
- 96 cores
Thread Count
- AMD EPYC 9256
- 48 threads
- AMD EPYC 9646
- 192 threads
SMT Support
- AMD EPYC 9256
- Yes
- AMD EPYC 9646
- Yes
Base Clock
- AMD EPYC 9256
- 2.85 GHz
- AMD EPYC 9646
- 2.8 GHz
Boost Clock
- AMD EPYC 9256
- 4.5 GHz
- AMD EPYC 9646
- 3.7 GHz
L3 Cache
- AMD EPYC 9256
- 96 MB-62%
- AMD EPYC 9646
- 256 MBBest
Socket
- AMD EPYC 9256
- SP8
- AMD EPYC 9646
- SP8
Multi-Socket Support
- AMD EPYC 9256
- Dual Socket
- AMD EPYC 9646
- Dual Socket
Memory Channels
- AMD EPYC 9256
- 8 channels
- AMD EPYC 9646
- 8 channels
Memory Type
- AMD EPYC 9256
- DDR5 RDIMM
- AMD EPYC 9646
- DDR5 RDIMM
Max Memory Speed
- AMD EPYC 9256
- 8000 MT/s
- AMD EPYC 9646
- 8000 MT/s
Registered Memory Required
- AMD EPYC 9256
- Yes
- AMD EPYC 9646
- Yes
PCIe Lanes
- AMD EPYC 9256
- 128 lanes
- AMD EPYC 9646
- 128 lanes
PCIe Generation
- AMD EPYC 9256
- PCIe 6.0
- AMD EPYC 9646
- PCIe 6.0
TDP
- AMD EPYC 9256
- 190 W
- AMD EPYC 9646
- 300 W
Configurable TDP Max
- AMD EPYC 9256
- 220 W
- AMD EPYC 9646
- 300 W
Memory Bandwidth
- AMD EPYC 9256
- 512 GB/s / 819.2 GB/s
- AMD EPYC 9646
- 512 GB/s / 819.2 GB/s
PCIe
- AMD EPYC 9256
- PCIe 6.0 x128
- AMD EPYC 9646
- PCIe 6.0 x128
Memory Support
- AMD EPYC 9256
- DDR5 RDIMM | MRDIMM, 8-Channel, Up to 8000 MT/s / Up to 12800 MT/s
- AMD EPYC 9646
- DDR5 RDIMM | MRDIMM, 8-Channel, Up to 8000 MT/s / Up to 12800 MT/s
Which one should you pick?
Choose 9256 if you want the higher memory channels (8 channels vs 8 channels) and the higher PCIe lanes (128 lanes vs 128 lanes).
Choose 9646 if you want the higher L3 cache (256 MB vs 96 MB).