AMD Ryzen Threadripper PRO 3975WX socket: sWRX8
The AMD Ryzen Threadripper PRO 3975WX uses sWRX8, the 4094-contact LGA socket for Threadripper PRO workstations. It is a 32-core Castle Peak chip at 280 W for WRX80 boards with 8-channel DDR4 memory.
- Socket
- sWRX8
- Launched
- July 14, 2020
- Cores and threads
- 32 and 64
- Default TDP
- 280 W
- Codename
- Castle Peak
- Segment
- Workstation
- Clocks
- 3.5 / 4.2 GHz
AMD Ryzen Threadripper PRO 3975WX specifications
| Cores | 32 |
|---|---|
| Threads | 64 |
| Core architecture | Zen 2 (Castle Peak) |
| Clocks | 3.5 GHz base, up to 4.2 GHz boost |
| Cache | 128 MB L3, 16 MB L2 and 2048 KB L1 |
| Default TDP | 280 W |
| Manufacturing process | TSMC 7 nm FinFET |
| Memory support | DDR4-3200 ECC, 8 channels, up to 2 TB |
| PCI Express | 128 PCIe Gen4 lanes from the CPU |
| Integrated graphics | None (discrete card required) |
| Multiplier | Locked |
| ECC memory | Supported, RDIMM with ECC |
| Package | FC-LGA4094, socket sWRX8 |
| Cooler in the box | None, 280 W workstation heatsink required |
Motherboard and chipset compatibility
AMD Ryzen Threadripper PRO 3975WX needs a motherboard with a sWRX8 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| WRX80 workstation | WRX80 | Works out of the box |
Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for sWRX8.
sWRX8 at a glance
| Type | LGA, 4,094 contacts |
|---|---|
| Package size | 75.4 × 58.5 mm |
| Introduced | July 2020 |
| Memory | DDR4-3200 ECC UDIMM, RDIMM, LRDIMM or 3DS RDIMM, 8 channels, up to 2 TB |
| Cooler mounting holes | Large TR4-SP3 mount (sTRX4, sWRX8, TR4 and SP3 compatible) |
What the Threadripper PRO 3975WX is
The Ryzen Threadripper PRO 3975WX is the thirty two core mid point of the Castle Peak workstation range that AMD listed on July 14 2020 for sWRX8 boards. Its Zen 2 cores run 3.5 GHz base with boost up to 4.2 GHz across 64 threads. Cache is 128 MB of L3 with 16 MB of L2 and 2048 KB of L1, and the TSMC 7 nm FinFET process feeds many cores through eight memory channels.
Thirty two cores suit rendering, compilation and simulation that scale with threads. The 3.5 GHz base trails smaller PRO models by several hundred megahertz, which costs some responsiveness in lightly threaded modelling but pays back in throughput. Eight DDR4 channels with ECC keep the cores fed, and 128 Gen4 lanes cover multiple GPUs and NVMe arrays.
AMD rates the chip at 280 W default TDP with locked multiplier. The sWRX8 package carries 4094 contacts in a large LGA with carrier frame, and discrete graphics are required. The 90 C maximum operating temperature guides workstation airflow with vendor qualified air or liquid.
Socket and motherboard compatibility
The 3975WX fits sWRX8 on WRX80 with 8 DDR4 channels. Consumer sTRX4 operation with 4 channels needs a non-PRO chip, so PRO planning centres on WRX80 board choice. Firmware support for Castle Peak PRO must be installed from the maker page. The LGA socket uses three Torx screws in order with the orange carrier.
WRX80 boards for 32 cores lean to workstation designs with BMC, ECC validation and multi GPU layouts. Power stages target 280 W sustained with strong VRMs, so dual EPS and clean case airflow are requirements rather than options. Memory population with RDIMM modules follows one DIMM per channel for full bandwidth to 2 TB, with larger LRDIMM kits where validated.
The 32-core point often marks the sweet spot for studios that render daily but still model on the same machine. Buyers who mainly model with occasional renders gain little over sixteen cores, while those who run long encodes and builds use all 32 cores well. The LGA, PGA and BGA: CPU package types explained guide places sWRX8 LGA handling against desktop sockets for builders new to Threadripper torque procedures.
Memory, PCIe and cooling
DDR4 to DDR4-3200 in 8 channels with ECC gives full bandwidth to 2 TB. Primary slots first per manual, with RDIMM versus UDIMM validated per board. Larger kits need board validation for LRDIMM versus 3DS RDIMM. Memory speed past 3200 MT/s helps only where the board qualifies it, since workstation stability favours validated speeds.
PCIe from the CPU gives 128 Gen4 lanes for two GPUs at by 16 plus Gen4 SSDs at by 4 and high speed networking. Chipset lanes add SATA, USB and extra slots. Cooling needs a 280 W workstation tower or liquid unit, because 32 cores hold high power under all-core rendering. No box cooler is included.
ECC joins the CPU as a lasting choice. Boards that route ECC with RDIMM correct single bit errors in long jobs, which matters more than headline memory clocks for farm reliability. Population with eight matched modules beats mixed kits for bandwidth and error coverage.
Upgrade paths
On WRX80 the nearby steps are the 16-core AMD Ryzen Threadripper PRO 3955WX for higher clocks at lower core count and the 64-core AMD Ryzen Threadripper PRO 3995WX where throughput dominates. Many owners gain more from a second GPU or more memory first. Filling 8 channels and adding fast NVMe help large scenes without a chip swap.
Moving to HEDT on sTRX4 changes channels and lanes with a board change for desktop oriented builds without ECC needs. For most 3975WX owners the value order is memory to 8 channels, then GPUs, then a core step on the same sWRX8 socket where jobs scale.
Used buyers check firmware first. A WRX80 board that shipped with a 32-core part in 2020 may need no update for another Castle Peak PRO, but a jump to Chagall PRO 5000WX needs a firmware update that adds the new IDs. The twelve core AMD Ryzen Threadripper PRO 3945WX shows the clock focused entry on the same socket for reference.
Frequently asked questions
What socket does the Threadripper PRO 3975WX use?
Socket sWRX8 (LGA 4094) on WRX80 with 8 DDR4 channels. It needs Castle Peak PRO firmware support and does not work in sTRX4 boards.
What memory does the 3975WX use?
DDR4-3200 ECC in 8 channels to 2 TB, with RDIMM, LRDIMM and 3DS RDIMM on most boards. One DIMM per channel gives full bandwidth.
How many cores does the 3975WX have?
Thirty two cores and 64 threads at 3.5 GHz base and up to 4.2 GHz boost, with 128 MB L3 and a 280 W TDP for throughput workstation work.
Is the 3975WX good for gaming?
It runs creation and simulation with discrete GPUs, but gaming alone does not use 32 cores well. High throughput helps renders and builds, while board cost and 280 W cooling exceed gaming needs.
Sources and verification
- AMD Ryzen Threadripper PRO 3975WX specifications (AMD)
- Socket sWRX8 - 4094 contacts and WRX80 (Wikipedia)
- Zen 2 Castle Peak workstation CPUs (Wikipedia)
Facts last checked against these sources on . Page last edited on .