Nvidia showed off a mockup of its future Rubin Ultra GPUs with the NVL576 Kyber racks and infrastructure at GTC 2025. These are intended to ship in the second half of 2027, more than two years away, and yet, as an AI infrastructure company, Nvidia is already well on its way to planning how we get from where we are today to where it wants us to be in a few years. That future includes GPU servers that are so powerful that they consume up to 600kW per rack.
The current Blackwell B200 server racks already use copious amounts of power, up to 120kW per rack (give or take). The first Vera Rubin solutions, slated for the second half of 2026, will use the same infrastructure as Grace Blackwell, but the next Rubin Ultra solutions intend to quadruple the number of GPUs per rack. Along with that, we could be looking at single rack solutions that consume up to 600kW, as Jensen Huang verified during a question-and-answer session, with full SuperPODS requiring multi-megawatts of power.
Kyber is the name of the rack infrastructure that will be used for these platforms.
Image 1 of 9
There are no hard specifications yet for Rubin Ultra, but there are performance targets. As discussed during the keynote and in regards to Nvidia’s data center GPU roadmap going beyond Blackwell Ultra B300, Rubin NVL144 racks will offer up to 3.6 EFLOPS of FP4 inference in the second half of next year, with Rubin Ultra NVL576 racks in 2027 delivering up to 15 EFLOPS of FP4. It’s a huge jump in compute density, along with power density.
Each Rubin Ultra rack will consist of four ‘pods,’ each of which will deliver more computational power than an entire Rubin NVL144 rack. Each pod will house 18 blades, and each blade will support up to eight Rubin Ultra GPUs — along with two Vera CPUs, presumably, though that wasn’t explicitly stated. That’s 176 GPUs per pod, and 576 per rack.
The NVLink units are getting upgrades as well and will each have three next-generation NVLink connections, whereas the current NVLink 1U rack-mount units only have two NVLink connections. Either prototypes or mockups of both the NVLink and Rubin Ultra blades were on display with the Kyber rack.
No one has provided clear power numbers, but Jensen talked about data centers in the coming years potentially needing megawatts of power per server rack. That’s not Kyber, but whatever comes after could very well push beyond 1MW per rack, with Kyber targeting around 600kW if it keeps with the current 1000~1400 watts per GPU of the Blackwell series.