On Clustering & Power
What is a cluster?
In one line: a cluster is several engines wired together (by way of NVIDIA's NVLink) so their memories act as one shared pool, rather than separate, isolated parcels.
The honest part: not every gathering of engines is a true cluster. Plugging several desktop cards into one case does not combine their memories — each card's memory remains its own, and a model too large for one card remains too large with three more beside it. A true datacenter cluster (such as an NVLink server, or the GB300 NVL72 rack) physically joins the engines' memory controllers, so the whole company may address one combined pool.
True clusters we keep in stock
H200 HGX 4-GPU NVLink Server
| Engines | 4 |
|---|---|
| Combined memory | 564 GB pooled |
| Combined power | 2800 W |
| Combined price | $140,000 |
Real cluster: these 4 GPUs share one NVLink memory domain, so their memory truly adds up to 564 GB.
H200 HGX 8-GPU NVLink Server
| Engines | 8 |
|---|---|
| Combined memory | 1128 GB pooled |
| Combined power | 5600 W |
| Combined price | $280,000 |
A full 8-GPU NVSwitch domain — all 8 GPUs' memory is addressable as one 1,128 GB pool.
NVIDIA GB300 NVL72 (full rack)
| Engines | 72 |
|---|---|
| Combined memory | 20480 GB pooled |
| Combined power | 135,000-140,000 W depending on workload |
| Combined price | $5,000,000 |
The largest real cluster that exists today: 72 Blackwell Ultra GPUs across the rack share one 20 TB NVLink memory pool.
Not clusters — memory remains separate
NVIDIA RTX 5090
A single card only — no NVLink, so a second one does not add memory.
NVIDIA RTX PRO 6000 Blackwell
The largest VRAM of any single card, but still just one card — no NVLink bridge, so multiple units don't pool.
NVIDIA H200 (single GPU)
Sold standalone, this card's 141 GB is only usable by itself. It only pools with other H200s inside a matched NVLink server — see the HGX configurations below.
Making power real
Watts alone mean little to most people, so every engine and every recommended build in this house is translated into two everyday comparisons:
- Homes: an average home draws roughly 1,200 W continuously. Divide any build's wattage by 1,200 to see how many homes' worth of power it draws, around the clock.
- Electric-carriage batteries: a typical electric car's battery holds roughly 90 kWh (90,000 Wh). Divide 90,000 by a build's wattage to see how many hours it takes to burn through one full battery's worth of energy.