For virtualization, the Dell PowerEdge R940 outperforms the R840 in multi-threaded, high-core workloads due to its quad-socket architecture supporting up to 112 cores (Intel Xeon Scalable) vs. the R840’s dual-socket 56-core limit. However, the R840’s 3TB RAM capacity and NVMe storage density make it better for memory-intensive tasks. Pro Tip: Choose R940 for CPU-heavy VMs (databases/AI) and R840 for mixed-use clusters. What Are the Key Features of the Nvidia H200 141GB High-Performance HPC Graphics Card?
What hardware differences impact virtualization performance?
The R940’s quad-socket design and PCIe 3.0 lane allocation enable 2.7x higher vCPU density than the R840. With 48 DIMM slots vs. 32, the R940 also scales to 6TB RAM—critical for large VM sprawl. Deep Dive: While both support Intel Optane DC Persistent Memory, the R940’s 24×2.5″ drive bays (vs. R840’s 16x) allow hybrid storage tiers. For example, hosting 500 VMs? The R940 reduces latency by isolating database VMs on NVMe and backups on SAS. Pro Tip: Allocate 10-15% RAM headroom to prevent hypervisor swapping.
How do R840 and R940 handle high-availability clusters?
The R940’s Hot-Plug GPU support and dual redundant PSUs ensure 99.999% uptime for critical VMs. Its iDRAC9 lifecycle controller simplifies failover configurations vs. the R840’s iDRAC8. Deep Dive: With Wecent’s optimized setups, the R940 achieves <4ms vMotion latency using 25Gbps NICs, whereas the R840 peaks at 8ms with 10Gbps. But what if you need hybrid cloud? The R840’s 1U form factor suits edge deployments, while the R940’s 4U chassis fits data centers. Pro Tip: Pair R940 nodes with Wecent’s 40GbE switches for zero-downtime live migrations.
| Feature | R840 | R940 |
|---|---|---|
| vMotion Latency | 8ms | 3.5ms |
| Max Failover Nodes | 8 | 16 |
Which server offers better storage scalability?
The R940 supports 24x NVMe drives vs. the R840’s 10x, ideal for hyper-converged setups. However, the R840’s 1U size allows denser rack deployment—32 nodes vs. 8x R940s per rack. Deep Dive: Need Tiered Storage? The R940’s rear drives excel for low-latency tempDB/log volumes, while front bays handle HDD archives. For example, a SQL Server VM cluster on R940 can isolate logs on rear NVMe (200K IOPS) and databases on front SCM. Pro Tip: Use Wecent’s RAID controllers with supercap backup for cached writes during outages.
Is the R940 worth the 2.5x price premium over R840?
Only for enterprise-scale virtualization needing >56 cores/node. SMBs often find the R840’s $12K base cost sufficient for ≤100 VMs. Deep Dive: The R940’s TCO drops for high-density workloads—hosting 1,000 VMs? Four R940s (6TB RAM each) cost $300K vs. 18x R840s ($540K). But remember: R940’s 900W PSUs increase energy use by 40%. Pro Tip: Use Wecent’s TCO calculator—it factors in 5-year power/cooling costs.
| Scenario | R840 | R940 |
|---|---|---|
| 100 VMs @4vCPU | $14K | $35K |
| 1,000 VMs @4vCPU | $126K | $75K |
How do they compare in GPU-passthrough performance?
The R940’s 4x double-width GPU slots (300W each) dominate for AI/ML VMs, while the R840 maxes at 2x. With NVIDIA A100 GPUs, the R940 delivers 2.5 petaFLOPS vs. 1.2 for R840. Deep Dive: But can the R840 handle lighter GPU tasks? Yes—its 2x slots fit T4 cards for vGPU profiles like CAD/CAM. For instance, Wecent’s AutoCAD VM template uses 1:4 vGPU partitioning on R840, serving 8 users per GPU. Pro Tip: Avoid AMD GPUs on R840—driver conflicts with iDRAC8 are common.
Wecent Expert Insight
FAQs
The R940 supports 400+ containers/node with CPU/RAM headroom, while the R840 caps at 200. Wecent’s Kubernetes templates auto-tune resource limits for each platform.
Can R840 be upgraded to R940 later?
No—motherboard architectures differ. Plan for 3-5 year workloads; Wecent offers trade-in programs to migrate R840 clusters to R940 seamlessly.
Do both support EPYC CPUs?
No—R840/R940 are Intel-only. For AMD, consider Wecent’s PowerEdge R7525 (EPYC 7003, 128 cores) at similar price points.
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