Intel® Xeon™ 656
The Intel Xeon 656 is a server processor released on January 1, 2026, built on the Granite Rapids architecture. It has 20 cores and 40 threads, a base clock of 2.90 GHz, a maximum boost of 4.80 GHz, 72 MB of L3 cache, a 210 W TDP and the FCLGA4710 socket.
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Overview
SummaryThe Intel Xeon 656 is a workstation processor with 20 cores and 40 threads, built on the Granite Rapids architecture. It launched in Jan 2026. Clocks run from 2.9 GHz base to 4.8 GHz boost. A 72-MB L3 cache backs the cores (5.7 MB per core). It addresses DDR5 memory up to 4 GB across 8 channels. The chip drops into the FCLGA4710 socket and exposes PCIe 5.0 (128 lanes). Rated TDP is 210 W. Notable platform capabilities: AMX, AVX-512, Extended Page Tables (EPT), Control-flow Enforcement (CET).
Performance
12 metricsThe Intel Xeon 656 scores 3,826 in single-core performance and 64,897 in multi-core performance (PassMark CPU Mark ratings). From those two ratings Feex computes 15,757 for overall performance, 47,539 for productivity performance, 42,580 for creator performance, 78,688 for engineering performance and 27,702 for gaming performance. Its multi-core throughput works out to 3,245 per core, 1,622 per thread and 309 per watt. Its computed efficiency index is 1,087. Its performance index is 195, so its overall performance is 95% above the Intel Core i5-12400 (index 100). Each bar shows the score as a share of a reference ceiling, which is the larger of the 99th-percentile score across the Feex CPU database and a fixed baseline.
How these scores are computed
Single-core and multi-core performance are PassMark CPU Mark single-thread and multi-thread ratings. Every other figure on this page's performance section is computed by Feex from those two ratings plus core count, thread count and TDP, so it is a derived value and not a separate benchmark run.
- Overall performance is the geometric mean of the two ratings: the square root of single-core times multi-core.
- Productivity performance is 0.65 times multi-core plus 1.4 times single-core.
- Creator performance is 0.55 times multi-core plus 1.8 times single-core.
- Engineering performance is multi-core times the smaller of 1.4 and (0.9 plus cores divided by 64).
- Gaming performance is 3 times single-core plus 0.25 times multi-core.
- Performance per core, per thread and per watt divide the multi-core rating by physical cores, logical threads and TDP in watts.
- The efficiency index is the square root of single-core times multi-core, divided by the square root of TDP.
- The performance index is overall performance divided by the overall performance of the Intel Core i5-12400 (8,069), times 100.
Workload Benchmarks
8 workloadsScores for individual PassMark CPU Mark test categories. Higher is better. These are measured test scores, not computed from the single-core and multi-core ratings.
In the individual workload tests the Intel Xeon 656 scores 227,563 in integer math, 180,570 in floating-point math, 875,799 in compression, 43,305 in cryptography, 5,505 in physics simulation, 68,305 in vector SIMD, 381 in the prime sieve and 89,999 in sorting. Higher is better. Compared with the Intel Core i5-12400, it is 286% above in integer math, 293% above in floating-point math, 284% above in compression, 277% above in cryptography, 405% above in physics simulation, 340% above in vector SIMD, 469% above in the prime sieve and 297% above in sorting. Each bar shows the score as a share of that workload's reference ceiling, the larger of the 99th-percentile score across CPUs with a recorded value and a fixed baseline.
Core Configuration
7 specsThe Intel Xeon 656 has 20 physical cores and runs 40 logical threads. It does not use a hybrid performance and efficiency core layout. It runs 2 threads per core. It runs at a base clock of 2.90 GHz and boosts up to 4.80 GHz.
Architecture & Generation
7 specsThe Intel Xeon 656 is a workstation processor, belongs to the Intel Xeon family, uses the Granite Rapids architecture and carries the codename Granite Rapids. It launched in Jan 2026.
Cache
6 specsThe Intel Xeon 656 has 2.19 MB of L1 cache, 40 MB of L2 cache and 72 MB of L3 cache. That adds up to about 114.2 MB of cache, or 5.71 MB per core. Each core has 2 MB of private L2 cache.
Cache Hierarchy
3 levelsThe Intel Xeon 656 has a 3-level cache hierarchy: L1 at 2.2 MB, L2 at 40 MB and L3 at 72 MB. L3 is the largest level and makes up about 63% of the cache listed here.
Memory Support
6 specsThe Intel Xeon 656 supports DDR5 memory, addresses up to 4 GB of memory and uses 8 memory channels. It does not support DDR4 and LPDDR memory.
Platform & Compatibility
3 specsThe Intel Xeon 656 uses the FCLGA4710 socket, supports PCI Express 5.0 and provides up to 128 PCIe lanes.
Power & Thermals
1 specThe Intel Xeon 656 has a rated TDP of 210 W.
Platform Capabilities
14 supported, 0 not supportedInstruction sets, security, virtualization, AI acceleration and OS readiness. Features are listed as supported, explicitly not supported, or not recorded; a feature that is not recorded is not the same as unsupported.
Instruction Sets
6 supportedSecurity and Reliability
4 supportedVirtualization
3 supportedOS Compatibility
1 supportedThe Intel Xeon 656 supports AMX, AVX-512, AVX2, 64-bit (x86-64), SSE4.1 and SSE4.2 among its instruction set features. Feex has no record for AES-NI, AVX, AVX-VNNI, CET, CET-IBT and CET-SS, which is different from being unsupported.
The Intel Xeon 656 supports Control-flow Enforcement (CET), Boot Guard, OS Guard and Mode-Based Execute Control among its security features. Feex has no record for AES-NI, Execute Disable (NX), Hardware RNG, Hardware Shield, OS Guard (SMAP) and SGX, which is different from being unsupported.
The Intel Xeon 656 supports Extended Page Tables (EPT), VT-d (DMA Remapping) and VT-x (Hardware Virtualization) among its virtualization features. Feex has no record for VT-x with EPT, IOMMU, Second-Level Address Translation and Unrestricted Guest, which is different from being unsupported.
Feex records the Intel Xeon 656 as Windows 11 eligible.
Physical & Manufacturing
1 specThe Intel Xeon 656 is manufactured by Intel. It launched at a price of $1,539.
Naming & Aliases
3 specsThe Intel Xeon 656 is also identified by the model number 656.
Real-world compute in the Feex fleet
No machines yetNo Feex fleet machines with the Intel Xeon 656 have reported compute telemetry yet, so real-world compute for this processor is not recorded.
Data Coverage
56% recordedFeex has recorded 56% of the specifications it tracks for the Intel Xeon 656. Values Feex does not hold are shown as "Not recorded" rather than estimated.
Not recorded: Core Configuration: Efficiency Cores, All-Core Boost and Unlocked Multiplier. Architecture & Generation: ISA Family and Market Status. Cache: L4 Cache. Memory Support: Memory Bandwidth, ECC Memory and Max Memory Speed. Graphics: Integrated Graphics, Graphics Model, Graphics Base Clock, Graphics Max Clock, Execution Units, Display Outputs and Max Video Memory. Platform & Compatibility: Package and Package Size. Power & Thermals: Base Power, Maximum Turbo Power, Configurable TDP (Min), Configurable TDP (Max), Max Junction Temperature and Tcase. Physical & Manufacturing: Transistor Count, Die Size, Die Count and Foundry. Naming & Aliases: Normalized Name, SKU, Processor Number and Part Number.
Common questions
11 answeredHow many cores and threads does the Intel Xeon 656 have?
The Intel Xeon 656 has 20 cores and 40 threads.
What architecture does the Intel Xeon 656 use?
The Intel Xeon 656 is built on the Granite Rapids architecture.
What socket does the Intel Xeon 656 use?
The Intel Xeon 656 uses the FCLGA4710 socket.
What memory does the Intel Xeon 656 support?
The Intel Xeon 656 supports DDR5 up to 4 GB across 8 channels.
How fast does the Intel Xeon 656 run?
The Intel Xeon 656 can boost up to 4.8 GHz, with a 2.9 GHz base clock.
What is the TDP of the Intel Xeon 656?
The Intel Xeon 656 has a TDP of 210 W.
How does the Intel Xeon 656 perform?
In the Feex normalized performance dataset, the Intel Xeon 656 scores 64,897 multi-core and 3,826 single-core.
What advanced capabilities does the Intel Xeon 656 support?
Notable platform capabilities reported for the Intel Xeon 656 include AMX, AVX-512, Extended Page Tables (EPT), Control-flow Enforcement (CET).
What is the Intel Xeon 656 best for?
Based on its specifications, the Intel Xeon 656 is well suited for Workstation & rendering workloads, High-FPS gaming & low-latency tasks, Server / professional infrastructure.
How much cache does the Intel Xeon 656 have?
The Intel Xeon 656 has 2240 KB of L1 cache, 40960 KB of L2 cache and 72 MB of L3 cache.
How does the Intel Xeon 656 compare with the Intel Core i5-12400?
The Intel Xeon 656 has a computed performance index of 195, which is 95% above the Intel Core i5-12400 (index 100). The index is derived from the single-core and multi-core ratings.