Dell PowerEdge R740 / R740xd supported CPUs (Xeon Scalable matrix)
The R740 and R740xd share one dual-socket LGA3647 board and one supported-CPU list: every Intel Xeon Scalable tier from Bronze to Platinum, in both 1st-gen (Skylake-SP) and 2nd-gen (Cascade Lake) silicon, up to 28 cores and 205W per socket. This matrix covers what fits, what firmware a 2nd-gen upgrade requires, and where cooling becomes the limiting factor.
What CPUs does the Dell PowerEdge R740 support? The Dell PowerEdge R740 and R740xd accept one or two LGA3647 (Socket P) Intel Xeon Scalable processors — 1st-gen Skylake-SP and 2nd-gen Cascade Lake — from Bronze through Platinum, up to 28 cores and 205W TDP per socket. Running 2nd-gen silicon requires BIOS 2.1.x or newer; a 1.x BIOS supports 1st-gen only. See the full compatibility tool.
The R740 and R740xd share one dual-socket LGA3647 board and one supported-CPU list: every Intel Xeon Scalable tier from Bronze to Platinum, in both 1st-gen (Skylake-SP) and 2nd-gen (Cascade Lake) silicon, up to 28 cores and 205W per socket. This matrix covers what fits, what firmware a 2nd-gen upgrade requires, and where cooling becomes the limiting factor.
R740 / R740xd CPU platform at a glance
Both chassis are Dell 14th-generation (14G) 2U servers built on the Intel C620 (Lewisburg) chipset. The 2.5"/3.5" storage layouts differ — the R740xd adds mid-bay and rear drive options — but processor support is identical across the two models, and Dell documents them in a single combined technical guide.
| Attribute | Specification |
|---|---|
| Sockets | 2 × LGA3647 (Socket P) |
| Supported generations | 1st-gen Xeon Scalable (Skylake-SP) and 2nd-gen (Cascade Lake), incl. Cascade Lake Refresh "R" SKUs |
| Max cores | 28 per socket / 56 per system |
| Max TDP | 205 W per socket |
| Interconnect | Intel UPI, 2–3 links, 9.6–10.4 GT/s depending on tier |
| PCIe | 48 lanes PCIe 3.0 per CPU |
| Memory | 24 DDR4 DIMM slots (12 per CPU, 6 channels); up to 2666 MT/s with 1st-gen, up to 2933 MT/s with select 2nd-gen CPUs; Optane DC Persistent Memory (DCPMM) with select 2nd-gen SKUs |
| Chipset | Intel C620 (PCH) |
If you are deciding between 2U and 1U in the same generation, the CPU support list below applies equally to the R640 — the difference is thermal headroom and expansion, covered in our R740 vs R640 comparison.
Supported CPU matrix: Bronze through Platinum, 1st vs 2nd gen
Dell's technical guide lists the full supported roster — roughly 130 SKUs. The matrix below shows each tier with representative, commonly stocked parts. Cores, base clock, and TDP are per Intel ARK; every SKU shown appears in Dell's supported-processor table for the R740/R740xd.
| Tier / series | Generation | Representative SKUs (cores / base clock / TDP) | Max DDR4 speed | Notes |
|---|---|---|---|---|
| Bronze 31xx | 1st (Skylake-SP) | 3106 (8C / 1.7 GHz / 85 W) | 2133 MT/s | No Turbo, no Hyper-Threading; entry tier |
| Bronze 32xx | 2nd (Cascade Lake) | 3204 (6C / 1.9 GHz / 85 W) | 2133 MT/s | No Turbo; light-duty only |
| Silver 41xx | 1st (Skylake-SP) | 4110 (8C / 2.1 GHz / 85 W), 4114 (10C / 2.2 GHz / 85 W) | 2400 MT/s | 2 UPI links at 9.6 GT/s |
| Silver 42xx | 2nd (Cascade Lake) | 4210 (10C / 2.2 GHz / 85 W), 4214 (12C / 2.2 GHz / 85 W), 4216 (16C / 2.1 GHz / 100 W) | 2400 MT/s | Best price-per-core on the used market |
| Gold 51xx | 1st (Skylake-SP) | 5118 (12C / 2.3 GHz / 105 W) | 2400 MT/s | 10.4 GT/s UPI, but one AVX-512 FMA unit |
| Gold 52xx | 2nd (Cascade Lake) | 5218 (16C / 2.3 GHz / 125 W), 5222 (4C / 3.8 GHz / 105 W) | 2666 MT/s | 5222 targets per-core licensing |
| Gold 61xx | 1st (Skylake-SP) | 6130 (16C / 2.1 GHz / 125 W), 6148 (20C / 2.4 GHz / 150 W), 6152 (22C / 2.1 GHz / 140 W) | 2666 MT/s | 3 UPI links; dual AVX-512 FMA |
| Gold 62xx | 2nd (Cascade Lake) | 6230 (20C / 2.1 GHz / 125 W), 6244 (8C / 3.6 GHz / 150 W), 6248 (20C / 2.5 GHz / 150 W), 6254 (18C / 3.1 GHz / 200 W), 6258R (28C / 2.7 GHz / 205 W) | 2933 MT/s | 6258R delivers Platinum 8280-class specs at Gold pricing |
| Platinum 81xx | 1st (Skylake-SP) | 8168 (24C / 2.7 GHz / 205 W), 8180 (28C / 2.5 GHz / 205 W) | 2666 MT/s | Top of the Skylake-SP stack |
| Platinum 82xx | 2nd (Cascade Lake) | 8280 (28C / 2.7 GHz / 205 W) | 2933 MT/s | M/L variants raise per-socket memory limits |
Dell's list also includes the later Cascade Lake Refresh parts — 6258R, 6248R, 5218R, 4210R, 3206R — which are frequent best-value picks. To check a specific SKU against a specific chassis configuration before you buy, run it through our compatibility tool.
Upgrading to 2nd-gen (Cascade Lake): firmware rules
The firmware requirement is unambiguous. Dell's support documentation states that BIOS 2.1.x or newer is required for 14G servers running 2nd-generation Xeon Scalable processors, and that 1.x.x BIOS releases support 1st-gen (Skylake-SP) only. An R740 on a 1.x BIOS will not POST with Cascade Lake silicon installed.
- Update before you swap. Flash the BIOS to a current 2.x release while the original 1st-gen CPU is still installed, then power down and swap processors. Update iDRAC alongside the BIOS — Dell pairs BIOS and iDRAC releases, and a current iDRAC simplifies recovery if anything goes wrong.
- Do not downgrade afterward. Dell documents a known issue where downgrading from BIOS 2.4.8 to an older 2.x.x can halt the server at POST; the fix landed in 2.5.4. On a Cascade Lake system, stay on a recent 2.x release.
- What the upgrade buys you: memory bus speed rises from 2666 to 2933 MT/s on Gold 62xx / Platinum 82xx SKUs, Optane DC Persistent Memory (DCPMM) becomes available on select SKUs, and you gain Intel Deep Learning Boost (VNNI) plus hardware-level side-channel mitigations.
Note that the memory ceiling follows the CPU, not the chassis: a 2933 MT/s DIMM behind a Silver 4210 still trains at 2400 MT/s. Plan DIMM purchases against the processor you are upgrading to, not the one you are removing. Refurbished dual-socket platforms with these CPUs pre-validated are listed in our servers catalog.
TDP, heatsinks, and cooling caveats
The board accepts up to 205 W per socket, but the heatsink and fan configuration must match the processor's TDP band and the chassis build. Dell sells a distinct heatsink kit for R740/R740xd processors of 125 W or greater in configurations without mid-bay drives or GPUs (customer kit 412-AAIU); GPU-ready and mid-bay builds use different thermal kits. Practical rules:
- Crossing 125 W means checking the heatsink. An R740 sold with 85 W Silver CPUs may carry the standard heatsink. Dropping in 150–205 W Gold/Platinum parts without the correct higher-performance heatsink risks thermal throttling or shutdown.
- High-TDP plus dense storage is the tight case. Dell's recommended ambient is 30°C (operating range 10–35°C), with documented exceptions for R740xd GPU and NVMe configurations. A 24-bay R740xd running 205 W parts leans hard on all six fans.
- Single-CPU systems still need the blanks. With one processor, the CPU2 socket blank and its memory blanks must stay installed for airflow. The system boots only from the CPU1 socket, and with a single CPU only Riser 1 (1A/1B/1D) and Riser 2B remain functional.
- Fans are N+1 redundant — the platform tolerates one fan failure, but sustained high-TDP loads with a failed fan will raise fan speeds and acoustics significantly.
Matched pairs: dual-socket population rules
Dell's installation guidance requires processor 1 and processor 2 population to match, with identical memory configuration behind each socket. In practice for the used market:
- Buy the same model number for both sockets. Two different SKUs — even same core count and TDP — is an unsupported configuration.
- Prefer matched steppings. Mixed steppings of the same SKU may POST, but matched pairs pulled from the same system are the clean choice and what we ship by default.
- Populate memory symmetrically. Each CPU owns 12 of the 24 DIMM slots across 6 channels. A second CPU with empty channels wastes the bandwidth you paid for; an absent second CPU also disables its 48 PCIe lanes and the slots routed to it.
Upgrade path by workload
Typical swaps we see on refurbished R740/R740xd systems, assuming the firmware and heatsink rules above are met:
| Workload | Common starting point | Upgrade target | Rationale |
|---|---|---|---|
| General virtualization | Silver 4110 / 4114 | Gold 6230 (20C, 125 W) or 6248 (20C, 150 W) | Roughly doubles cores per host and lifts memory to 2933 MT/s |
| Per-core-licensed databases | Gold 5118 | Gold 6244 (8C, 3.6 GHz) or 6254 (18C, 3.1 GHz) | Maximum clock per licensed core; 6254 needs 200 W-class cooling |
| Storage node (R740xd) | Silver 4210 | Silver 4216 or Gold 5218 | Moderate cores at 100–125 W leaves thermal headroom beside 24 drive bays |
| HPC / analytics | Gold 6148 | Gold 6248 / 6258R | Dual AVX-512 FMA units plus higher sustained clocks |
| Max consolidation / VDI | Gold 6152 | Gold 6258R or Platinum 8280 (28C, 205 W) | 56 cores per 2U; 6258R matches 8280 core count at lower cost |
For storage-heavy builds, pair the CPU choice against the backplane and drive plan — our R740 compatible drives guide covers SAS/SATA/NVMe options per backplane.
Last verified 16 July 2026 against Dell’s PowerEdge R740/R740xd technical specifications.
Related reading: Is buying a used server safe? · HPE DL380 Gen10 memory compatibility · Dell R740 vs R640
Frequently asked questions
My R740 shipped with 1st-gen Xeon Scalable. Can it run 2nd-gen (Cascade Lake) CPUs?
Yes. Every R740/R740xd board supports both generations. The only gate is firmware: Dell requires BIOS 2.1.x or newer for 2nd-gen processors — 1.x BIOS releases support 1st-gen only. Flash a current 2.x BIOS (and matching iDRAC) with the original CPU installed, then swap.
What is the maximum CPU the R740 supports?
The platform tops out at 28 cores and 205 W per socket. The Platinum 8280 (28C / 2.7 GHz / 205 W) is the flagship; the Gold 6258R matches its 28 cores and 2.7 GHz base at a much lower market price and is usually the smarter refurbished buy.
Do the R740 and R740xd support the same processor list?
Yes — they share the same dual-socket LGA3647 board and one supported-CPU table in Dell's combined technical guide. The caveat is thermal: R740xd configurations with mid-bay drives, 24x NVMe, or GPUs carry stricter cooling and ambient-temperature rules that can constrain high-TDP choices.
Can I mix two different CPU models in a dual-socket R740?
No. Dell requires matching processor population across both sockets. Use two of the same model number — ideally a matched pair from the same stepping — and mirror the memory configuration behind each CPU.
Do I need a different heatsink for a higher-TDP CPU?
If the upgrade crosses into the 125 W-or-greater band, check the installed heatsink first. Dell specifies separate heatsink kits by TDP band and chassis configuration (standard, GPU-ready, and mid-bay builds each differ). Running a 150–205 W processor on a heatsink specced for 85 W parts will throttle.
Will an LGA3647 Xeon pulled from another vendor's server work in an R740?
Yes — Intel Xeon Scalable CPUs are not vendor-locked, so a chip from an HPE or Lenovo system works. What does not transfer is the mounting hardware: the R740 uses Dell's processor-and-heatsink module with its own carrier clip, so the bare CPU must be fitted to a Dell carrier and heatsink.