The Precision 5820, 7820 and 7920 are Dell's three tower workstation tiers from the same generation. They differ in one decision that drives everything else: how many processors the board takes. That sets the memory ceiling, the number of graphics cards, the power supply and the price.
Specification comparison
| Precision 5820 | Precision 7820 | Precision 7920 | |
|---|---|---|---|
| Processor sockets | One | One or two | One or two |
| Processor support | Intel Xeon W-2000 family or Intel Core X series, up to 18 cores | Intel Xeon Scalable, 1st or 2nd generation, up to 28 cores each | Intel Xeon Scalable, 1st or 2nd generation, up to 28 cores each |
| Memory channels | Four-channel DDR4 | Six-channel DDR4 ECC | Six-channel DDR4 ECC at 2666 MHz |
| DIMM slots | 8 | 12 (dual-CPU) | 24 (12 per processor; both processors must be fitted to use all 24) |
| Maximum memory | Up to 512GB at 2666MHz or 256GB at 2933MHz (ECC RDIMM); up to 256GB at 2666MHz (non-ECC UDIMM) | Up to 768GB at 2933MHz | Up to 1.5TB with dual processors; up to 3TB with select processor SKUs |
| Graphics slots | Two PCIe x16 Gen 3 | Two PCIe x16 Gen 3 | Up to four PCIe x16 Gen 3 |
| Total graphics power | Up to 600W, up to 2 x 300W double-width | Ceiling depends on processor count | Up to 900W |
| Internal storage | Up to 4 x 2.5" / 3.5" SATA (up to 6 x 2.5" + 5 x 3.5" with the 5.25" bay populated) | Up to 4 x 2.5" / 3.5" SATA (same 5.25" bay expansion) | Up to ten 3.5" or 2.5" drives with the MegaRAID 9460-16i controller |
| NVMe | Front hot-plug M.2 / U.2 (lane-limited on Core X i9/i7); up to 4 M.2 via add-in card | Up to 2 front hot-plug M.2 / U.2; up to 4 M.2 via add-in card | Up to eight M.2 NVMe on expansion cards |
| Storage controllers | Integrated Intel SATA plus software RAID; optional Broadcom MegaRAID. SAS is not available on all Core X configurations | Integrated Intel SATA plus software RAID 0/1/5/10; optional Broadcom MegaRAID | MegaRAID 9460-16i for the full ten-drive configuration |
| Power supply | 425W, 685W or 950W | 950W, 80 PLUS Gold, externally accessible and lockable | 1400W, 80 PLUS Gold |
| Chassis | Tower | Tower, 16.45" H x 6.95" W x 20.4" D, approximately 34lb | Tower, 17.05" H x 8.58" W x 22.29" D; an optional 19-inch rackmount rail kit is listed |
How to choose
The 5820 is the single-socket tier, and its chipset matters
The 5820 takes one processor, and that processor can be either a Xeon W-2000 or an Intel Core X part. The choice is not cosmetic. Core X configurations run on the Intel X299 chipset rather than C422, and several capabilities narrow as a result: PCIe lanes are more limited for front NVMe on i9 and i7 parts, SAS is not available on all Core X builds, and some graphics cards are not offered. If you want ECC memory and the full storage path, specify a Xeon W build.
Its four memory channels and eight DIMM slots are the real ceiling. 512GB is reachable, but only at 2666MHz with ECC RDIMMs.
The 7820 adds the second socket and two more memory channels
Moving to the 7820 buys six-channel memory, a second processor option of up to 28 cores, and 768GB at a higher 2933MHz rating than the 5820 can reach at capacity. What it does not buy is more graphics: it carries the same two x16 graphics slots as the 5820, and its graphics power ceiling moves with processor count rather than being fixed.
This is the tier to pick when the workload is thread-hungry or memory-hungry but not GPU-hungry — simulation, large assemblies, compile farms, heavy virtualised test environments.
The 7920 is the one that changes the graphics and storage picture
The 7920 is the only one of the three that doubles the graphics capacity: up to four x16 Gen 3 cards and up to 900W of total graphics power, against two slots and 600W on the 5820. It is also the only one with 24 DIMM slots and a 1.5TB ceiling, and the only one with a ten-drive internal storage configuration.
Two constraints are worth knowing before you specify one. All 24 DIMM slots require both processors to be fitted — a single-processor 7920 has 12. And the ten-drive configuration depends on the MegaRAID 9460-16i controller, not on the chassis alone.
A note on what these figures mean
The table above describes what each platform supports as a design. It does not describe what is fitted to any particular refurbished unit, or what TekBoost currently has available to configure. Those are separate questions, and the configuration pages answer them for real stock.
Where to go next
- Dell Precision 5820 specifications and options
- Dell Precision 7820 specifications and options
- Dell Precision 7920 specifications and options
- Which Dell Precision tower workstation is right for your work?
- Browse refurbished Dell Precision workstations
- Check memory options for these platforms with the RAM Advisor
Hardware bought from TekBoost carries our standard 3-year warranty with Next Business Day part replacement, subject to the terms, exclusions and conditions on that page. If you would rather describe the workload than pick a model, request a quote.