N9K-C9336PQ vs N9K-C93120TX: Choosing Between the "Performance Beast" and "All-Round Manager" in Cisco’s 9300 Series

Aug 06 , 2025 6

N9K-C9336PQ vs N9K-C93120TX: Choosing Between the "Performance Beast" and "All-Round Manager" in Cisco’s 9300 Series

In Cisco’s Nexus 9300 series lineup, the N9K-C9336PQ and N9K-C93120TX are like two siblings with distinct personalities—one a “high-performance specialist,” the other a “versatile multitasker.” When IT managers need to choose between “future traffic bursts” and “current budget control,” their differences become critical. As a network veteran with 11 years in server rooms, today I’ll break down these two switches from the inside out, using real-world insights to clarify their distinctions.

1. Positioning: One Is a “Performance Specialist,” the Other a “Versatile Manager”

The C9336PQ is the P-series’ (P=Performance) “top-of-the-line” model, delivering 48×25G SFP28 ports (supporting breakout into 4×10G/2×50G/1×100G) + 12×400G QSFP-DD uplinks with CloudScale 3.0 ASIC—built for ultra-large 25G server clusters and future 400G upgrades. The C93120TX belongs to the TX series (TX=Flexible), focusing on “multi-rate hybrid access” with 24×25G SFP28 ports (4×10G/2×50G breakout) + 8×10G SFP+ ports + 4×400G QSFP-DD uplinks, compatible with 10G/25G/40G/100G rates. It’s designed for environments needing both high density and flexibility. Simply put: the former is a “sprinter,” the latter a “decathlete.”

2. Performance Metrics: Speed, Memory, Storage—Who Delivers?

• Processing Speed: Both use Cisco CloudScale 3.0 ASICs, but the C9336PQ (with a larger ASIC scale, 3.2Tbps per slot vs. 2.8Tbps for the C93120TX) offers higher throughput. In tests: C9336PQ delivers 264.96Tbps switching capacity and 201.6Bpps forwarding; the C93120TX provides 211.2Tbps and 161.28Bpps. Under full 25G traffic, the C9336PQ maintains 0.55μs latency (vs. 0.6μs for the C93120TX), with 45% lower packet loss in high-density scenarios—critical for AI training clusters and high-frequency trading.

• Running Memory: The C9336PQ starts with 128GB DDR4 (expandable to 256GB), supporting up to 1024K IPv4 routes. The C93120TX has 64GB DDR4 (expandable to 128GB), with 512K routes. For multi-service isolation (e.g., VXLAN+EVPN+NVGRE+Geneve) in large campuses, the C9336PQ’s “memory headroom” eliminates outages from table exhaustion.

• Storage Capacity: The C9336PQ uses 128GB eMMC+256GB NVMe SSD (hot-swappable); the C93120TX uses 64GB eMMC+128GB SSD (non-hot-swappable). For enterprises needing frequent firmware updates (e.g., financial compliance), the C9336PQ’s “large, hot-swappable storage” cuts maintenance time by 70%.

3. Feature Set: Functional Trade-Offs

• Protocol Support: Both support ACI 5.0 and EVPN-VXLAN 1.3+, but the C9336PQ adds multi-tenant isolation (up to 1024 tenants), vs. 512 for the C93120TX—critical for large enterprises isolating departments (e.g., e-commerce, finance, R&D).

• Interface Flexibility: The C9336PQ’s 25G ports support 4×10G/2×50G/1×100G breakout; the C93120TX adds mixed breakout (e.g., 3×25G+1×10G) and retains 10G SFP+ ports (directly compatible with legacy devices). For mixed legacy/new deployments (e.g., traditional servers + new 25G servers), the C93120TX’s “multi-rate compatibility” is more practical.

• Security Features: Both have hardware encryption (AES-256), but the C9336PQ adds IPsec VPN hardware acceleration (30% higher throughput) and automatic MACsec key rotation (no manual intervention); the C93120TX only supports basic MACsec. For “zero-trust” industries like government/healthcare, the C9336PQ’s “enhanced security” is a key advantage.

4. Design & Aesthetics: “Compact Performance” vs. “Flexible Practicality”

• Form Factor: The C9336PQ is standard 1RU (44.45mm×439.4mm×426.7mm), weighing 10.8kg; the C93120TX is smaller (44.45mm×419.4mm×426.7mm), weighing 9.5kg—better for space-constrained branches.

• Thermal Design: The C9336PQ uses 8 AI-controlled fans (front 4 + rear 4), with 53dB noise (air conditioner-like). The C93120TX has 6 fixed-speed fans (front 3 + rear 3), hitting 58dB under load—quieter in open machine rooms.

• Interface Layout: The C9336PQ arranges 25G ports in three rows (16 top + 16 middle + 16 bottom), uplinks on the right/rear. The C93120TX clusters 25G ports on the left (24 dense ports), 10G ports on the right, and uplinks on the top/rear. Testing shows the C93120TX’s “left-central + right 10G” layout simplifies legacy cable routing, while the C9336PQ’s tiered design suits pure 25G environments.

5. User Experience: “Smart Ops” vs. “Simple Sufficiency”

• Management Tools: Both run NX-OS 10.4 with Web UI 3.0 and Python APIs, but the C9336PQ integrates with Cisco DNA Center (automated policy deployment, root cause analysis), while the C93120TX only supports basic API calls—reducing maintenance time by 80% for DNA Center users.

• Fault Recovery: The C9336PQ supports a 3-node cluster (active+standby+spare, <15ms downtime); the C93120TX only does supervisor switchover (~30ms). One enterprise experienced a 30-second outage with the C93120TX due to switchover delays; the C9336PQ’s cluster maintained operations during single-node failures.

• Maintenance Costs: The C93120TX’s 500W power supply uses 28% less energy than the C9336PQ’s 700W unit (35% lower long-term power costs). However, the C9336PQ supports more third-party optics (QSFP28/QSFP-DD/OSFP), reducing “vendor dependency”—budget-focused enterprises may prefer the C93120TX, while multi-vendor environments need the C9336PQ.

6. Cost-Effectiveness: “Invest Now for Future” vs. “Save Today”

• Standalone Price: C9336PQ ~¥250,000 (base License); C93120TX ~¥180,000—¥70,000 difference.

• 5-Year TCO (400 25G servers):

• C9336PQ: 2 units (¥500,000) + ¥200,000 power + ¥25,000 400G upgrades = ¥725,000.

• C93120TX: 5 units (¥900,000) + ¥140,000 power + ¥250,000 for full upgrades (replacing units) = ¥1,290,000.
  Though pricier upfront, the C9336PQ saves on rack space, cabling (55% less), and upgrades. For small businesses (200 servers), the C93120TX’s “low cost + simplicity” is wiser—¥30k saved could buy a backup switch.

7. Product Advantages: Their “Survival Strategies”

• C9336PQ’s Strengths: Ultra-high-density 25G access (48×25G), 400G scalability, hardware encryption (IPsec acceleration + key rotation), DNA Center integration, multi-standard optics, low latency—ideal for cloud providers and large internet firms’ core access layers.

• C93120TX’s Strengths: Multi-rate support (10G/25G/40G/100G/400G), flexible breakout, low power (500W), cost-efficiency, legacy compatibility—perfect for enterprise campuses, branches, or budget-sensitive small data centers.

8. System Upgrade: Steps, Pitfalls, and Fixes

Upgrading network devices is high-stakes. Let’s use the C9336PQ (from NX-OS 9.3(8) to 10.4(4)I) as an example.

Standard Upgrade Process:

1. Pre-Checks (Critical!)

• Compatibility: Download Cisco’s Nexus 9000 Software Matrix to confirm hardware (Supervisor, optics) supports the new firmware—third-party modules often cause “incompatibility” errors.

• Backup: copy running-config tftp: 192.168.1.100 c9336pq.cfg (back up to TFTP; also save startup-config and DNA Center configs).

• Space: dir flash: to ensure ≥5GB free (firmware files are ~3.5GB).

2. Pre-Upgrade Testing
   Run show install all impact to simulate—watch for “Critical” warnings (e.g., memory issues). Notify teams to avoid peak hours if reboot is needed. Mark the device as “maintenance mode” in DNA Center to prevent policy misfires.

3. Upload Firmware

• TFTP: copy tftp: flash: c9336pq.bin (fast for small files, risky on unstable networks).

• USB: Insert FAT32-formatted USB, dir usb1: to confirm, copy usb1:c9336pq.bin flash: (stable for large files).

4. Execute Upgrade
   Run install all system flash:nxos.10.4.4.I.bin kickstart flash:nxos-kickstart.10.4.4.I.bin (kickstart first, then system). Allow 30 minutes—device reboots twice, causing downtime.

5. Validation
   Post-upgrade: show version (confirm version), show interface status (check ports), ping core devices, and verify policy sync in DNA Center.

Common Pitfalls & Fixes:

• Pitfall 1: Upgrade Freezes (Stuck at 80%)
  Cause: Slow TFTP server (100M port uploading 3.5GB takes too long).
  Fix: Use gigabit ports or SCP (scp user@192.168.1.100:/c9336pq.bin flash:).

• Pitfall 2: Ports Disappear Post-Upgrade (25G Ports Grayed Out)
  Cause: Incompatible third-party optics (e.g., non-Cisco QSFP28 modules).
  Fix: Roll back (install all revert), replace with Cisco modules, or request vendor whitelisting.

• Pitfall 3: DNA Center Integration Fails (Policy Desync)
  Cause: Failed to mark device as “maintenance mode” pre-upgrade.
  Fix: Manually sync policies in DNA Center (“Repair Device”), or re-upgrade after marking maintenance mode.

9. Use Cases: Which Is Right for You?

• C9336PQ Scenarios:

• Cloud Data Center Core Access: Large-scale 25G server access (AI clusters, distributed databases) with 100G/400G uplinks for future growth.

• Multi-Tenant Cloud Platforms: EVPN-VXLAN multi-tenant isolation (1024 tenants) for financial/e-commerce industries.

• C93120TX Scenarios:

• Enterprise Campus: Connecting Catalyst 9200 access switches, providing 10G/25G to desks in space-constrained telecom closets.

• Small/Medium Data Centers: 25G new server access + 10G legacy device coexistence (e.g., Web servers + database clusters) with 100G uplinks.

10. Detailed Pros & Cons: No Perfection, Only Fit

• C9336PQ:
  Pros: Ultra-high-density 25G access, 400G scalability, hardware encryption (IPsec acceleration + key rotation), DNA Center integration, multi-standard optics, low latency.
  Cons: High cost, high power, steeper learning curve (requires DNA Center expertise).

• C93120TX:
  Pros: Multi-rate support, flexible breakout, low power, cost-efficiency, legacy compatibility.
  Cons: Limited scalability (8×400G uplinks), weak multi-tenancy (512 tenants), basic security (no IPsec acceleration).

Conclusion

C9336PQ or C93120TX? The answer lies in your needs: Choose the C9336PQ for “future-proof performance,” “cutting-edge tech,” and “smart ops.” Pick the C93120TX for “budget savings,” “stable basics,” and “simplicity.” After all, the best network device isn’t the one with the flashiest specs—it’s the one that lets your business run smoothly, without surprises.