Synology E10M20-T1 Review: 10GbE and Two NVMe Cache Slots From One PCIe Slot

In 1956, IBM shipped the first computer hard drive. The IBM 350, the disk unit at the heart of the RAMAC system, held fifty spinning 24-inch platters, weighed roughly a ton, and stored five million characters — call it about 3.75 megabytes in modern money. It did not sit on a desk. It was crated, forklifted and flown, and businesses leased it by the month because almost nobody could justify buying one outright.

The IBM 350 — a ton of machine for less storage than one photo from your phone (photo: Wikimedia Commons).

Storage has kept its side of that bargain spectacularly. A pair of M.2 sticks the size of two sticks of gum now holds hundreds of thousands of times what that machine did. What has not kept pace is the wire between your storage and your desk. Gigabit Ethernet showed up in homes and small offices around the turn of the century, and for an enormous number of networks it is still the ceiling — about 110 MB/s on a good day, which a single modern hard drive can already outrun. That gap is exactly what the Synology E10M20-T1 exists to close.

What the E10M20-T1 actually is

It is one PCIe 3.0 x8 add-in card that performs two completely different upgrades to a compatible Synology NAS at the same time: it adds a 10-gigabit copper Ethernet port, and it adds two M.2 NVMe SSD slots. On a NAS with a single expansion slot — which is most of them — that combination is the whole reason the card exists. You do not have to choose between a faster network and an SSD cache.

We have one in stock: Synology E10M20-T1 10GbE + dual M.2 NVMe adapter card, $249.99. It is listed open box — the retail carton was opened, but the card itself is still sealed in its factory anti-static bag and seated in the foam tray, with the accessory bags still in the box. We have not installed or power-tested it.

Upgrade one: the 10GBASE-T port

The network side is a single RJ-45 running 10GBASE-T (IEEE 802.3an) over ordinary copper, so there are no SFP+ modules or fiber patch cords to buy. Critically, it auto-negotiates the whole ladder: 100 Mb/s, 1 Gb/s, 2.5 Gb/s and 5 Gb/s (802.3bz) and 10 Gb/s. That matters for real budgets — you can drop this card in today behind a cheap 2.5-gig switch, get two and a half times your current speed, and step up to a 10-gig switch later without touching the NAS again.

The offload feature list is the usual serious-NIC set: 9 KB jumbo frames, TCP/UDP/IP checksum offload, TSO, LSO, RSS, GRO and GSO. In plain terms, the card does the packet grunt work so your NAS CPU can keep serving files. Both low-profile and full-height brackets are included, and the card measures 7.89 x 2.82 x 0.7 inches.

Upgrade two: two M.2 NVMe slots

The two slots are M-key NVMe, and they take both 2280 and 22110 lengths — the longer 22110 size is worth knowing about, because that is the length a lot of enterprise SSDs with power-loss protection come in, and those are the drives most people should be putting in a cache. On most Synology systems these slots are used for SSD cache: one drive gives you a read-only cache, and a read-write cache generally wants two so a single SSD failure cannot take your data with it. Whether your particular model and DSM version can also turn NVMe into a storage volume depends on the model, so check your NAS product page rather than assuming.

Check compatibility first — genuinely

This is the one place people get burned. Synology only supports add-in cards on specific NAS models with the right PCIe slot, and this is an x8 card. Before you buy, look up your exact NAS model on Synology's site and confirm the E10M20-T1 is on its compatible-expansion-card list. A 10-gig card in an unsupported chassis is an expensive paperweight.

Do you actually need 10 gigabit?

Honest answer: if one person streams movies off the NAS, no — gigabit is fine and the cache would do more for you than the port. You want this card if you edit video or photos directly off the share, run virtual machines with the NAS as a datastore, back up several machines at once during the same nightly window, or have a six-plus-drive array whose disks together can comfortably beat a gigabit link. Remember that a fast port at one end does nothing on its own: you need a switch and a client NIC that can keep up, too.

The rest of the network shelf

If you are wiring up the room around it, we also have the TP-Link TL-SG105E 5-port easy-smart managed switch at $23.99 (VLANs and QoS on a five-port box, useful for keeping backup traffic off everything else), the plain TL-SG105 5-port unmanaged gigabit switch at $19.99 in a metal case, a TP-Link Archer TX21UH Wi-Fi 6 AX1800 USB adapter at $28.99 for an older desktop that never got Wi-Fi 6, an AX3000 Wi-Fi 6 range extender with AP mode at $46.74, and a NETGEAR CM700 32x8 DOCSIS 3.0 cable modem at $59.99 if you are still renting one from Xfinity, Cox or Spectrum.