NVIDIA RTX 4090

Every number, explained

GPU memory

24 GB GDDR6X

GPU memory is the workbench — the whole model must fit here or it doesn't run at all. Regular RAM cannot substitute: it sits on a link far too slow for the GPU, which would spend nearly all its time waiting instead of computing.

Memory bandwidth

1,008 GB/s TODO: verify

How fast the GPU re-reads the model from its own memory. To generate every single word, the GPU re-reads the ENTIRE model — all of it, every word. So faster memory means faster answers: double the bandwidth and the model talks roughly twice as fast.

Power draw

450 W — about 0.38 of one home's constant draw (a home draws ~1,200 W around the clock); one day (10.8 kWh) drains about 0.12 EV battery (an EV battery holds ~90 kWh).

Electricity burned every second the machine runs — this is a real monthly bill, not a spec-sheet footnote. We translate it below into homes and electric-car batteries so you can feel the size of it.

Form factor

Desktop PCIe card (fits a normal PC)

The CPU is the traffic director — it does almost none of the AI math. Don't overspend here; the GPU does the work.

Price

~$1,999 TODO: verify

Discontinued — verify current street price.

What it's for: The classic enthusiast card — runs models up to ~20B parameters entirely on one card.