The testing results shown in previous sections demonstrate that 25 GbE networking bottlenecks the performance of VxRail with vSAN Express Storage Architecture. Using 100 GbE networking within the rack unlocks the full performance potential of ESA.
When new technology is introduced, the initial cost of adoption is high, and this high cost often remains a customer concern long after the early adoption premium has passed. Today, however, there is no significant cost delta between 10 GbE and 25 GbE networking. Environments that do not require the bandwidth of 25 GbE are often built with 25 GbE in favor of 10 GbE. Several aspects drive this strategy, including standardizing a single network infrastructure or positioning for future growth in workload demands.
While there remains a price delta between 25 GbE and 100 GbE networking, it has narrowed significantly and may not have as high a premium as initially expected. When comparing costs, include all necessary components for a full end-to-end view and consider the increased bandwidth available. Less tangible benefits, such as easier cable management and improved cooling due to reduced cable clutter, are harder to quantify. While these benefits are not detailed here, they provide benefit to daily data center operations.
The table below compares the following networking configurations:
- Dual 25 GbE – the typical rack default in many data centers
- Dual 100 GbE – the growth engine for future rack deployments
Component | Dell PN | List price | Per port | 25 GbE | 100 GbE |
Broadcom 57414 dual 25 Gb | 540-BBUJ | $769 | $385 | $385 | - |
S5248F-ON 48 port 25 GbE | 210-APEX | $59,216 | $1,234 | $1,234 | - |
25 GbE Passive Copper DAC | 470-BBCX | $125 | $125 | $125 | - |
Broadcom 57508 dual 100 Gb | 540-BDEF | $2,484 | $1,242 | - | $1,242 |
S5232F-ON 32 port 100 GbE | 210-APHK | $62,475 | $1,952 | - | $1,952 |
100 GbE Passive Copper DAC | 470-ABOX | $360 | $360 | $360 | |
Total per port cost | - | - | - | $1,743 | $3,554 |
Table 2 shows the costs for delivering the various networking configurations. The 100 GbE solution is slightly more than twice as expensive as the 25 GbE solution; however, the following information details the benefits of this doubling in networking infrastructure investment:
- OLTP 32 K
- Peak IOPS increase of 78 percent with a substantial 49 percent drop in latency
- At 70 percent of maximum, IOPS increased 88 percent with a 20 percent drop in latency
- RDBMS 22 K
- Peak IOPS increase of 49 percent with a 20 percent drop in latency
- At 70 percent of maximum, IOPS increased 60 percent with a 19 percent drop in latency
- 512 K throughput
- Provides roughly two times the performance for dedicated workloads of Random Writes, Random Reads, Sequential Writes, and Sequential Reads
- Random writes: 106.2 percent increase
- Random reads: 138.6 percent increase
- Sequential writes: 92.3 percent increase
- Sequential reads: 126.4 percent increase
- Provides roughly two times the performance for dedicated workloads of Random Writes, Random Reads, Sequential Writes, and Sequential Reads