Labthrift Labthrift Buy the boring upgrade. Skip the rest.

Notes / Used vs new

Editorial, 22 Aug 2026. Specs from maker pages and recent street reports. We have not burned these units in. Affiliate tags are not live.

QNAP QSW-2104-2S: four 2.5G and two 10G SFP+, 12 W, fanless

The used Cisco 10G chassis is the temptation. This is the new pizza box for “NAS already has 10G, PCs are 2.5G.” Unmanaged. 12 V / 1 A brick. Two-year warranty, not TRENDnet lifetime.

US SKU: QSW-2104-2S-US / QSW-2104-2S-A-US. Two 10G SFP+ plus four 2.5G RJ45. Maker max 12 W. Fanless ventilated metal. Class B. Distinct from the CRS305 (SFP+ only) and from the 8-port 2.5G unmanaged myth post. The 8-port copper shopping list is still 2.5G switch.

Amazon ASIN B0BFC6QFRL snap $116. B&H listing $79.99 (was $129.99, $50 off) when fetched. Older Amazon ASIN B09B9CJQ2D exists for the same model family — confirm the US letter suffix. We have not burned one in.

The short list

BoxWhat it isStreet, 22 Aug 2026Buy if
QNAP QSW-2104-2S2× 10G SFP+ + 4× 2.5G, unmanaged, fanless, 12 V / 1 A, max 12 W, 2-year.Amazon B0BFC6QFRL snap $116. B&H $79.99 when fetched.NAS on a 10G DAC, four 2.5G endpoints, no VLAN tax. New. Not a used Cisco 10G chassis.
MikroTik CRS305-1G-4S+IN4× SFP+ only. SwOS/RouterOS. Fanless.Maker $149 / Amazon ~$136.Every hop is already SFP+.

Skip

Skip the used Cisco 10G Catalyst / Nexus for this mix of ports. We are not selling eBay chassis. Skip expecting lifetime paper — QNAP is two years on the hardware spec. Skip a random used optic; buy a new DAC in DAC + named X710. The used-vs-new heater test is still here.

Sources

QNAP QSW-2104-2S hardware spec (12 W, 12 V / 1 A, fanless, 2-year). Amazon B0BFC6QFRL. B&H 1733420-REG. Street moves.

Also in this lane

TRENDnet lifetime vs Cisco SmartNet you cannot transferOn a closet lot you do not get SmartNet. Buy new paper you can actually call. If the PSU wants 208 V, it does not belong in a closetA closet is a 120 V duplex. Buy the brick. 1U is for a rack. A closet gets a pizza box.Used 1U is deep, loud, and wants rails. The closet objects are pizza boxes.