Key takeaways
- IREN has a transmission connection agreement for a planned 800 MW campus at Bundey, South Australia. It says energization is expected to begin in 2028, not that 800 MW is already operating.
- Firmus and CDC originally described a Southgate alliance that could scale to 1.6 GW through 2028. Data Center Dynamics reported on October 6, 2026, that the partnership ended after 42 MW was deployed at CDC’s Melbourne facility.
- The 42 MW figure applies to the CDC-hosted Melbourne deployment. Firmus said the split does not change its separate development plans or contracted customer capacity.
- NVIDIA’s newer headline of up to 2 GW by 2027 covers eight Australian providers. It is not a combined capacity promise for Bundey and Southgate, and it does not move Bundey’s stated start date forward.
The comparison at a glance
| Measure | IREN Bundey | Firmus Project Southgate |
|---|---|---|
| Disclosed scale | Planned 800 MW campus | Former Firmus–CDC alliance targeted up to 1.6 GW; 42 MW deployed at CDC Melbourne when the rollout ended |
| Evidence behind the number | Signed transmission connection agreement | Original Firmus announcement plus October 2026 reporting on the partnership’s end |
| Timing | Energization expected to begin in 2028 | Melbourne deployment already reported at 42 MW; Firmus has other projects on separate schedules |
| NVIDIA role | IREN says it is applying the NVIDIA DSX reference architecture | Southgate announcements describe NVIDIA GB300 systems and NVIDIA participation |
| Main uncertainty | Approvals, construction sequence and the ramp from first power toward 800 MW | Which future Firmus sites proceed outside the former CDC rollout, and at what capacity |
These figures are not like-for-like measures of live compute. IREN’s 800 MW is a planned campus connection envelope. The 42 MW figure is deployed capacity at one CDC facility after a much larger partnership stopped. Treating them as two current operating campuses would erase the most important difference.
IREN Bundey: what the 800 MW number establishes
IREN announced Bundey on June 3, 2026. The company said it had signed a transmission connection agreement for a planned 800 MW data center campus about 78 miles northeast of Adelaide.
The electrical detail is unusually specific for an early-stage announcement. IREN said the agreement secures four 330 kV feeder exits at the utility substation and is expected to support up to 800 MW without network upgrades. That is meaningful evidence of grid planning, but it is not the same as an energized data center or an 800 MW IT load.
The timing matters just as much as the headline capacity. IREN said it was on track to commence energization from 2028. It also said early works and procurement would run alongside the satisfaction of regulatory approvals and conditions in the connection agreement. Readers comparing projects should therefore track first power, approved construction phases and contracted customer load separately.
NVIDIA’s September 2026 Australian ecosystem announcement adds a technology direction: IREN is applying the NVIDIA DSX reference architecture across its development portfolio, including Bundey. A reference architecture can guide power, cooling, networking and accelerated-computing design. It does not prove which GPU generation will be installed, how much capacity will be available on day one or when the full 800 MW will be reached.
Project Southgate: the original scale and the changed partnership
Firmus and CDC announced a much broader plan in October 2025. Firmus described initial Southgate stages in Tasmania and Melbourne of up to 150 MW, representing 54,000 NVIDIA GB300 GPUs, and a pathway to 1.6 GW of operational AI factories through 2028.
Firmus added customer detail in March 2026. It said a long-term contract covered approximately 18,400 NVIDIA GB300 GPUs at the Melbourne facility and that Southgate was a multi-site Australian programme. Those are company statements about contracted hardware and planned delivery, not independent measurements of operating capacity.
The CDC portion then changed materially. Data Center Dynamics reported on October 6 that Firmus and CDC had stopped working together on the Southgate rollout after deploying 42 MW at CDC’s Melbourne data center. The report said that site would no longer expand to the previously planned 150 MW.
That does not mean every Firmus development was cancelled. The same report quoted Firmus as saying the companies had mutually agreed earlier in 2026 not to proceed with the proposed development partnership and that the decision did not affect Firmus’s own development plans, contracted customer capacity, strategy or international partnerships. The clean reading is narrower: the 1.6 GW Firmus–CDC rollout is no longer a valid forward capacity baseline, while Firmus continues to pursue projects outside that alliance.
Where NVIDIA’s 2 GW announcement fits
NVIDIA subsequently announced an Australian data-center ecosystem buildout of up to 2 GW by 2027 across Firmus, Sharon AI, IREN, Megaport, ResetData, CDC, NEXTDC and AirTrunk. The providers are to operate their facilities, while NVIDIA supplies the DSX platform, accelerated computing, networking, software and ecosystem support.
That programme-level ceiling should not be allocated to individual projects without site-level evidence. In particular, IREN’s own release says Bundey energization starts from 2028. The 2 GW announcement therefore does not support saying Bundey will be online by 2027. It also does not restore the ended Firmus–CDC expansion.
For the broader context behind that umbrella figure, see our earlier explainer, NVIDIA Australia 2 GW AI Factory Target: What It Includes.
What engineers and investors should watch
1. Connection capacity versus IT load
A grid connection can define a maximum campus envelope while construction and customer deployments arrive in phases. Future Bundey updates should separate total connection capacity, energized capacity, critical IT load and contracted load.
2. Site-level delivery after a partnership change
Southgate should now be followed site by site. The 42 MW Melbourne deployment is evidence of delivery at CDC, while Firmus’s other Australian campuses need their own approval, power, construction and commissioning evidence.
3. Hardware claims versus operating status
An ordered or contracted GPU count does not by itself prove that all systems are installed and serving customers. The strongest updates will pair hardware counts with a named facility, an operating date and an electrical or customer-capacity measure.
4. Dates attached to the correct project
The national 2027 ambition, Bundey’s 2028 energization start and Southgate’s site-specific schedules answer different questions. Compressing them into one deadline produces a cleaner headline but a worse infrastructure model.
Bottom line
IREN Bundey and Firmus Southgate illustrate two different stages of Australian AI infrastructure. Bundey has a large, specific connection agreement and a stated start of energization from 2028, but it remains a planned campus. Southgate has a real 42 MW CDC-hosted deployment, while the much larger 1.6 GW partnership behind its original national rollout has ended.
The useful comparison is therefore not 800 MW versus an undisclosed number. It is a planned 800 MW grid-connected campus versus a 42 MW delivered phase whose original expansion vehicle changed. Future claims should be judged against site-level power, approvals and commissioning—not the largest programme headline.
Sources
This article was researched and fact-checked against the following sources:
- IREN Announces First Australian Data Center Campus - 800MW in South Australia (iren.gcs-web.com)
- Firmus Expands Project Southgate Across Australia (firmus.co)
- Firmus Signs Multi-Year Agreement with Global Hyperscale Customer at Project Southgate (firmus.co)
- Firmus and CDC end 1.6GW Project Southgate collaboration, deploy just 42MW (datacenterdynamics.com)
- NVIDIA Expands AI Infrastructure Capacity in Partnership With Australia’s Data Center Ecosystem (nvidianews.nvidia.com)
