Is anything not checked?

Jonsbo doesn't publish a height or thickness limit for the Z20, so those aren't checked.

Where do these numbers come from?

Jonsbo's published spec; card size from NVIDIA's spec page. Checked October 2026. Makers measure differently and connectors add a few millimetres, so treat a tight result as a reason to measure.

Every card in the Z20

Will it fit

Does the NVIDIA GeForce RTX 5090 Founders Edition fit in the Jonsbo Z20?

Fits

Yes. The NVIDIA GeForce RTX 5090 Founders Edition fits the Jonsbo Z20 with 59 mm of length to spare.

Length304 of 363 mm59 mm spare

Height137 mmNot published

Thickness2 slotsNot published

Exact measurements

Size	NVIDIA	Z20	Room
Length	304 mm	363 mm	59 mm spare
Height	137 mm	—	Not published
Thickness	2 slots	—	Not published

Jonsbo's published spec

Questions

Does the NVIDIA GeForce RTX 5090 Founders Edition fit in the Jonsbo Z20?: Yes. The NVIDIA GeForce RTX 5090 Founders Edition fits the Jonsbo Z20 with 59 mm of length to spare. Length 304 of 363 mm, height 137 mm (no published limit), thickness 2 slots (no published limit).
Is anything not checked?: Jonsbo doesn't publish a height or thickness limit for the Z20, so those aren't checked.
Where do these numbers come from?: Jonsbo's published spec; card size from NVIDIA's spec page. Checked October 2026. Makers measure differently and connectors add a few millimetres, so treat a tight result as a reason to measure.

Sources

Case: Jonsbo’s Z20 specifications, checked October 24, 2026. Jonsbo lists cards up to 363 mm long, 'depends on other hardware configurations'.
Card: NVIDIA’s spec page, checked October 23, 2026. NVIDIA publishes the slot count, not a thickness in millimetres, and asks for room for a 3-slot (61 mm) card for airflow.
Jonsbo publishes a length limit only, and says it depends on the rest of the build.

This card in other small cases

The card’s size, and all 25 cases

Other RTX 5090 cards in the Z20

Check another pair with the fit checker.

Based on published dimensions, not a guarantee. Check cable, cooler and connector clearance before you buy.