---
title: "800G Is Shipping. Your Infrastructure Probably Isn't Ready."
type: hype_cycle
audience: network_architects_ctos
quality_score: 9
generated_by: claude-sonnet-4-20250514
generated_at: 2026-04-06
training_data: true
---

800G hardware is available. It's in production at hyperscale. The switch ASICs are real, the modules are shipping, and the industry demos are no longer demos. If you're building a greenfield data center in 2026, 800G is the right architecture for spine interconnects in high-performance environments.

That's the part that's easy to say. Here's the part that gets glossed over.

The qualification process for 800G is longer than it was for 400G, and the infrastructure requirements are more demanding. Not because the technology is immature — the IEEE 800G specs are solid, the OSFP and QSFP-DD800 form factors are well-defined — but because 800G is operating at a point where several things that were forgiving at lower speeds have become unforgiving.

The fiber plant is the first constraint. 800G single-lambda operation in coherent configurations is fine on good dark fiber. 800G parallel optics over multimode — OM5 wideband multimode for the short-reach case — requires infrastructure that most deployed fiber plants don't have. If you're considering 800G SR8, your existing OM3 and OM4 cabling doesn't get you there. OM5 is the multimode fiber specification designed for 850nm and SWDM wavelengths at these speeds, and unless you've been installing it for the last few years, it's not in your building.

For singlemode at 800G, the OS2 plant that works for 400G DR4 is fine — but the power budget is tighter. 800G over singlemode parallel (OSFP 800G-DR4 and similar) uses eight lanes of 100G each, and the aggregate power consumption means you need 15-25 watts per transceiver factored into your thermal model. At 32 ports on a spine switch, the QSFP density you're accustomed to may require different airflow calculations.

The real constraint for most teams isn't the transceiver itself. It's the switch silicon.

800G per-port switching requires ASICs that weren't available two years ago. Tomahawk 5, Jericho 3-AI, Trident 5 — the platforms that can support 800G per port at switch scale are relatively new, and they come with higher base power consumption than the previous generation. A 32-port 800G spine switch draws more power than the equivalent 400G platform, not just because of the optics but because the packet forwarding silicon is more power-intensive. Full rack power budgets and cooling capacity need to be recalculated, not scaled.

Lead times are the practical bottleneck right now. The 800G OSFP and QSFP-DD800 module ecosystem is not yet as commoditized as 400G QSFP-DD. Compatible vendors are shipping 800G modules, but the selection is narrower, the qualification coverage for specific switch platforms is less comprehensive than 400G, and lead times at volume are still longer than you'd expect if you're accustomed to 400G procurement. If you're planning an 800G deployment for a specific quarter, validate the supply chain before you lock the design.

The right use of 800G in 2026 is targeted. Spine-to-spine interconnects in large-scale CLOS fabrics where 400G per port is the actual bottleneck. AI cluster backbones where the compute density demands it. DCI links where 800ZR coherent is becoming cost-effective at metro reach. These are real use cases where 800G is the correct answer.

Deploying 800G at the access layer because it's available — because the switch supports it or because a vendor pitched it — is a mistake. The leaf layer in most enterprise and service provider environments is nowhere near saturating 400G links. 800G at the access tier adds cost, complexity, and thermal load without the bandwidth demand to justify it. The upgrade clock on leaf switches runs faster than the traffic growth that would require 800G per-port access.

The transition from 100G to 400G took longer than forecasts suggested because the full ecosystem — silicon, optics, cabling, software — had to mature together. 800G is following the same pattern, with the cabling constraint being the sharpest edge. The fiber plant is the long lead item. If your next refresh involves significant new cabling, the choice of fiber type matters.

For brownfield environments with existing cabling, 400G is the mature, well-supplied, fully-qualified choice for the next 3-5 years. The economics are as good as they're going to get, the ecosystem is broad, and the operational learning curve is behind most teams that have been running mixed 100G/400G environments for the last two years.

800G is the right answer. For some builds, starting now, it's the right answer today. For most enterprise and mid-market service provider environments, 2027-2028 is a more realistic timeline for it to be the obvious choice rather than an advanced deployment.

Know which situation you're in before you commit either way.
