https://network-switch.com/pages/about-us
Executive takeaways
- If you need dense 10G fiber access with 100G uplinks (and room to grow with interface modules), start with S6520X-30HC-EI / S6520X-54HC-EI: they ship with QSFP28 100G uplinks that can break out to 4×25G.
- If 40G uplinks are enough today (or you plan to break out uplinks to add more 10G), S6520X-30QC-EI / S6520X-54QC-EI deliver QSFP+ 40G uplinks that can split into 4×10G.
- If you want the same EI-style "modular 10GE access + scalable uplinks" design but in the HI family, S6520X-30QC-HI is a clean 24×SFP+ + 2×QSFP+ choice (40G uplinks with 4×10G breakout).
- If you're building Wi-Fi 6/6E-era multi-gig edge with higher PoE power (cameras, APs, endpoints), the SI "UPWR" models are the practical picks-especially S6520X-26MC-UPWR-SI (multi-gig UPoE) and S6520X-54XC-UPWR-SI (48×multi-gig/10GBase-T + 4×QSFP+).
- For compact 10G aggregation / small distribution with mixed media, S6520X-16ST-SI stands out: 16×SFP+ plus 2×1/10GBase-T combo interfaces.
What the S6520X family is?
In 2026, enterprise switching design is increasingly "10G to the edge, 25G/100G northbound when needed." The H3C S6520X family maps cleanly to that reality: it's built around 10GE access/aggregation with flexible uplinks (40G/100G depending on model family) and expansion slots on the EI/HI variants for modular growth.
Think of S6520X as a set of role-based building blocks:
- Fiber-heavy 10G access / distribution (SFP+ dense)
- Aggregation with scalable uplinks (QSFP+ 40G or QSFP28 100G)
- Multi-gig copper edge with higher-power PoE (UPoE) for modern endpoints
- Small aggregation / mixed-interface closets where combo ports simplify migration
Verified model specifications
Notes: Specs below are taken from H3C product pages/datasheets and H3C hardware specification documents where available.
A) EI Series (Enhanced 10GE Switches)
| Model | Downlink ports | Uplinks | Expansion | Switching capacity / forwarding | Best fit |
| S6520X-30HC-EI | 24 × 1/10G SFP+ | 2 × QSFP28 100G (breakout to 4×25G) | 2 slots | 1680 Gbps / (705-1050 Mpps listed by table) | 10G access with 25G/100G-ready uplinks |
| S6520X-30QC-EI | 24 × 1/10G SFP+ | 2 × QSFP+ 40G (breakout to 4×10G) | 2 slots | 960 Gbps / (705-1050 Mpps listed by table) | cost-efficient 10G + 40G uplink |
| S6520X-54HC-EI | 48 × 1/10G SFP+ | 2 × QSFP28 100G (breakout to 4×25G) | 2 slots | 2160 Gbps / (705-1050 Mpps listed by table) | dense 10G distribution + 100G northbound |
| S6520X-54QC-EI | 48 × 1/10G SFP+ | 2 × QSFP+ 40G (breakout to 4×10G) | 2 slots | 1440 Gbps / (705-1050 Mpps listed by table) | high-density 10G + flexible 40G/10G uplinks |
B) HI Series (Advanced Aggregation 10GE Switches)
| Model | Downlink ports | Uplinks | Expansion | Switching capacity / forwarding | Best fit |
| S6520X-30QC-HI | 24 × 1/10G SFP+ | 2 × QSFP+ 40G (breakout to 4×10G) | 2 slots | 960 Gbps / (705-1050 Mpps listed by table) | aggregation/distribution with 40G uplinks |
C) SI Series (Multi-Gigabit 10GE Switches)
| Model | Downlink ports | Uplinks / extras | Switching capacity / forwarding | Best fit |
| S6520X-18C-SI | 16 × 1/10G SFP+ | 1 expansion slot | 480 Gbps / 357 Mpps | compact fiber aggregation |
| S6520X-26C-SI | 24 × 1/10G SFP+ | 1 expansion slot | 720 Gbps / 536 Mpps | higher-density SFP+ access/agg |
| S6520X-26MC-UPWR-SI | 24 × 100M/1G/2.5G/5G Base-T UPoE | 1 expansion slot; up to 90W PoE supported on these ports | multi-gig powered edge (APs/cameras/endpoints) | |
| S6520X-54XC-UPWR-SI | 48 × 100M/1G/2.5G/5G/10G Base-T UPoE | 4 × QSFP+ | high-density multi-gig/10G copper access with uplinks | |
| S6520X-16ST-SI | 16 × SFP+, with the two highest-numbered SFP+ ports forming combo interfaces with 2 × 1/10GBase-T ports | small aggregation / migration-friendly closet design |
Key differentiators
1. Uplink strategy: 40G breakout vs 100G breakout
The cleanest "first fork" is uplinks:
-
QSFP+ 40G → 4×10G breakout
Great when your upstream is 10G-heavy, or when you want to "convert" 40G uplinks into more 10G without changing chassis count. EI (QC) and HI (QC) explicitly support this breakout approach. -
QSFP28 100G → 4×25G breakout
Better when you're modernizing northbound bandwidth (25G aggregation, 100G core links, or heavy east-west). EI (HC) models provide QSFP28 and allow 25G breakout.
2. Fiber-first SFP+ density vs copper multi-gig with UPoE
Your edge reality matters more than "switch class" marketing:
- If endpoints are servers, storage gateways, or fiber-fed IDFs, the SFP+ dense EI/HI/SI (C) models make sense: you land 10G optics directly where you need them.
- If endpoints are Wi-Fi 6/6E APs, cameras, industrial sensors, or high-power terminals, copper multi-gig plus higher PoE is operationally simpler. The SI UPWR models are explicitly positioned for multi-gig + UPoE, including a stated 90W PoE capability on S6520X-26MC-UPWR-SI.
3. Modularity: expansion slots and interface modules (EI/HI)
EI and HI families include expansion slots and a menu of interface modules that lets you evolve without a forklift upgrade-examples listed include 25GE SFP28 modules and 100GE QSFP28 modules (model-dependent).
That matters when:
- you're not sure whether 40G is enough long-term
- you need to add ports later (rather than overbuy day one)
- you want to mix media types (fiber/copper) and speeds within one platform
Role-based selection
If your role is: 10G fiber access / distribution
- Choose S6520X-54HC-EI when you need 48×SFP+ and want 100G uplinks for a modern core/distribution layer.
- Choose S6520X-54QC-EI if upstream is mostly 10G/40G, and you value 40G→4×10G breakout flexibility.
- For smaller footprints, S6520X-26C-SI (24×SFP+) is a practical aggregation/access block with published switching/forwarding figures.
If your role is: multi-gig copper powered edge
- S6520X-26MC-UPWR-SI: 24× multi-gig (up to 5G) Base-T with UPoE, explicitly calling out 90W PoE support.
- S6520X-54XC-UPWR-SI: when you need a 48-port high-density copper edge with 10GBase-T capability and QSFP+ uplinks.
If your role is: small aggregation / migration staging
- S6520X-16ST-SI: useful when you're migrating to fiber but still need a couple of 10GBase-T handoffs. Its combo-interface design is explicitly documented.
If your role is: aggregation that stays 40G for now
- S6520X-30QC-HI (24×SFP+ + 2×QSFP+) is the straightforward HI-family fit.
Deployment scenarios
Scenario A - "Fiber-rich campus aggregation pod"
- Access layer uplinks land on dense SFP+ aggregation switches.
- If the upstream core is modernizing, the HC-EI models with QSFP28 100G uplinks reduce congestion and avoid uplink oversubscription sooner.
Scenario B - "Wiring closet upgrade for multi-gig endpoints"
- Wi-Fi 6/6E and high-performance endpoints push you beyond 1G.
- Multi-gig UPWR models reduce "midspan injector sprawl" and keep power centralized (operationally cleaner). S6520X-26MC-UPWR-SI explicitly supports UPoE and indicates high PoE output per port.
Scenario C - "High-density copper edge with uplink flexibility"
- For large floors/branches: S6520X-54XC-UPWR-SI provides 48 copper multi-gig/10GBase-T ports plus 4×QSFP+ uplinks, which can be used for 40G aggregation or for breakout strategies depending on optics/cabling.
Scenario D - "Cost-controlled 10G distribution that stays 40G"
- If 100G is not required this refresh cycle, QC models (EI or HI) provide dense 10G plus 40G uplinks and breakout to 10G.
Operations & resiliency highlights
Across the EI/HI/SI product pages, H3C positions the family as 10GE access switching with resiliency and flexible management, and SI specifically highlights expansion/module flexibility and multi-gig forwarding.
A few practical ops notes based on the published hardware docs:
- SI hardware specification documents explicitly cover ports, LEDs, FRUs, and chassis views-handy for standardizing field replacement procedures.
- The SI family's model list (including ST/XT/C/MC/UPWR variants) is explicitly enumerated in the 2025 hardware spec document, which helps when you want consistent documentation across multiple sub-models.
FAQs
Q1: Should I prioritize 40G uplinks (QSFP+) or 100G uplinks (QSFP28) for a new build in 2026?
A: If your core/distribution is trending toward 25G/100G northbound, QSFP28 uplinks (e.g., EI "HC" models) reduce near-term rework because 100G can also break out to 4×25G. If your upstream is still largely 10G and you want more 10G fanout, QSFP+ 40G with 4×10G breakout can be a very cost-efficient choice.
Q2: What's the cleanest model split if I need both fiber distribution and multi-gig powered edge?
A: A common approach is EI (SFP+ dense + 40G/100G uplinks) for aggregation/distribution, paired with SI UPWR models for wiring closets where you need multi-gig copper and higher PoE output.
Q3: Which models are best when I expect to add ports or uplinks later without replacing the chassis?
A: EI and HI families explicitly include expansion slots and list multiple interface module types (including 25G and 100G modules on certain models), which is the "grow later" path.
Q4: I'm migrating from copper to fiber-what model helps me bridge both worlds with minimal pain?
A: S6520X-16ST-SI is specifically documented as having SFP+ ports plus 2×1/10GBase-T as combo interfaces-useful for phased migrations (keep two critical copper handoffs while shifting the rest to fiber).
Q5: Which S6520X-SI model is the "default" for a 24-port 10G SFP+ access/aggregation block?
A: S6520X-26C-SI provides 24×1/10G SFP+ and published performance figures, making it a straightforward 24-port SFP+ building block.
Q6: What's the best fit if I need 48 ports of multi-gig/10GBase-T plus uplinks?
A: S6520X-54XC-UPWR-SI is the high-density option in your list: 48× multi-gig/10GBase-T UPoE plus 4×QSFP+ uplinks.
Q7: Does the SI UPWR family explicitly support very high PoE output per port?
A: Yes-H3C's product page text specifically states S6520X-26MC-UPWR-SI supports UPoE on its multi-gig ports and indicates max 90W PoE support on those ports.
Q8: Are the EI "QC" models only for 40G, or can they also help expand 10G density?
A: EI QC models list QSFP+ ports that can be split into four 10G ports, which is often used to add more 10G uplinks or downstream 10G connections without changing the chassis.
Q9: I need dense 10G SFP+ and 100G northbound-what two EI models should I shortlist first?
A: S6520X-30HC-EI (24×SFP+) and S6520X-54HC-EI (48×SFP+) are the direct "100G uplink" EI options (QSFP28 with 25G breakout).
Q10: If I'm standardizing documentation for rollout teams, which source is best for chassis/LED/FRU details?
A: For the SI family, H3C publishes a Hardware Information and Specifications document that covers model lists and chassis views (including S6520X-16ST-SI).
Conclusion
Treat S6520X selection as a role decision:
- EI/HI when you want modular growth and fiber-heavy 10G with scalable uplinks (40G or 100G)
- SI when the problem is "modern edge reality": multi-gig copper, UPoE, compact aggregation, and migration-friendly combos
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