High-end, dual-socket, professional workstation made for hypercritical engineering and scientific tasks.

1. HP z840 Dell Tower 7910 Lenovo P900
Xeon® E5-2623v3 Xeon® E5-1603v3 N/A
Xeon® E5-2637v3 Xeon® E5-1607v3 Xeon® E5-1607v3
Xeon® E5-2603v3 Xeon® E5-2603v3 Xeon® E5-2603v3
Xeon® E5-2609v3 Xeon® E5-2609v3 Xeon® E5-2609v3
Xeon® E5-2620v3 Xeon® E5-2620v3 Xeon® E5-2620v3
Xeon® E5-2643v3 Xeon® E5-2643v3 Xeon® E5-2643v3
Xeon® E5-2630v3 Xeon® E5-2630v3 Xeon® E5-2630v3
Xeon® E5-2640v3 N/A Xeon® E5-2640v3
Xeon® E5-2667v3 Xeon® E5-2667v3 Xeon® E5-2667v3
Xeon® E5-2650v3 Xeon® E5-2650v3 Xeon® E5-2650v3
Xeon® E5-2660v3 N/A Xeon® E5-2660v3
Xeon® E5-2687Wv3 Xeon® E5-2687Wv3 Xeon® E5-2687Wv3
N/A N/A Xeon® E5-2650Lv3
Xeon® E5-2670v3 Xeon® E5-2670v3 Xeon® E5-2670v3
Xeon® E5-2680v3 Xeon® E5-2680v3 Xeon® E5-2680v3
N/A N/A Xeon® E5-2685v3
Xeon® E5-2690v3 N/A Xeon® E5-2690v3
Xeon® E5-2695v3 Xeon® E5-2695v3 Xeon® E5-2695v3
Xeon® E5-2683v3 N/A Xeon® E5-2683v3
Xeon® E5-2697v3 Xeon® E5-2697v3 Xeon® E5-2697v3
Sixteen cores N/A Xeon® E5-2698v3 Xeon® E5-2698v3
Eighteen cores Xeon® E5-2699v3 Xeon® E5-2699v3 N/A
DIMM slots 16 16 16
Max RAM 512GB 512GB 512GB
Max RAM Win 10 1TB 1TB 1TB
Quadro® K420 Quadro® K420 Quadro® K420
Quadro® K620 Quadro® K620 Quadro® K620
Quadro® K2200 Quadro® K2200 Quadro® K2200
Quadro® M4000 Quadro® M4000 Quadro® M4000
Quadro® M5000 Quadro® M5000 Quadro® M5000
Quadro® M6000 Quadro® M6000 Quadro® M6000
N/A Tesla® K20 Tesla® K20
Tesla® K40 N/A N/A
FirePro™ W2100 FirePro™ W2100 N/A
N/A FirePro™ W4100 N/A
FirePro™ W5100 FirePro™ W5100 N/A
FirePro™ W7100 FirePro™ W7100 N/A
Intel N/A Xeon® Phi 3120A N/A
# of 3.5" drives (up to) 4 3 6
# of 2.5" drives (up to) 4 4 10
Drives & controllers
Twelve cores
Fourteen cores
Memory
Graphics cards
NVIDIA
AMD
HP Z840 vs. Dell 7910 vs. Lenovo P900
Intel Processors
Quad-core
Six cores
Eight cores
Ten cores

2. Add'l2.5" drives in 5.25" bay 4 2 2
SATA 6 Gb/s ports 6 6 6
SAS w/ Add-in card Yes/4i4e Yes / 8i Yes / 8i
PCIeSSDs (AHCI) 256/512 GB 256/512 GB 256/512 GB
PCIeSSDs (NVMe) 256/512 GB N/A N/A
SATA SSDs (commercial) 128 GB-1 TB 128 GB-512 GB 128 GB-512 GB
SATA SSDs (enterprise) 240/480 GB N/A N/A
SATA 7.2K High Capacity 2/3/4 TB* 2 TB 2/3/4 TB
5.25" bays 2 1 2
3.5" bays 2 2 4
Slim ODD bay 1 1 1 via FLEX
PCIeGen 3 x16 / x8 02/01 02/01 2/0
PCIeGen 2 x4 / x1 01/01 01/01 02/01
PCI slots 1 1 1
Total USB ports 12 13 12
Front USB 3.0 4 1 4
Rear USB 3.0 4 3 4
Front USB 2.0 0 3 0
Rear USB 2.0 2 3 4
Internal USB 3.0 1 0 0
Internal USB 2.0 1 3 0
Total Thunderbolt Ports 1 1 1
425W90% efficient No Yes No
490W90% efficient No No Yes
525W80% efficient Yes No No
600W90% efficient Yes No No
650W92% efficient No No Yes
685W90% efficient No Yes No
700W90% efficient Yes No No
Bays & I/O expansion slots
USB ports
Power supply