Question SATA SSD versus M.2 NVMe SSD vs Memory Card (also an "SSD") ?

[DanielThommen]

Stupid Question, but why would you prefer one over the other?

Even a 512GB Memory Card is technically a SSD and could be mounted very easy with a card reader into a USB connector. Have WIN and all on it and start it from there (would that even work if USB is the booting device in BIOS)?

So what is better with a "real" SSD SATA (where you need an available SATA connector or a SATA-card (PCIe) where you could plug it in
...vs...
a SSD M.2 NVME (where you also need an adapter to connect it via PCIe)
...vs...
a SD card, connected via USB?

I guess whatever is connected to PCIe is faster than USB.

So is the fastest to get a PCIe-x4 adapter card for M.2 NVME and a SSD card that goes in there? But is the speed not also bottlenecked based on the PCIe (1.0, 2.0, 3.0 or 4.0)?
Or is a PCIe-x2 SATA card where you connect a SSD with a cable to it faster?
Or is a "SSD" SD Card connected via USB even faster?

 

[CountMike]

Stupid Question, but why would you prefer one over the other?

Even a 512GB Memory Card is technically a SSD and could be mounted very easy with a card reader into a USB connector. Have WIN and all on it and start it from there (would that even work if USB is the booting device in BIOS)?

So what is better with a "real" SSD SATA (where you need an available SATA connector or a SATA-card (PCIe) where you could plug it in
...vs...
a SSD M.2 NVME (where you also need an adapter to connect it via PCIe)
...vs...
a SD card, connected via USB?

I guess whatever is connected to PCIe is faster than USB.

So is the fastest to get a PCIe-x4 adapter card for M.2 NVME and a SSD card that goes in there? But is the speed not also bottlenecked based on the PCIe (1.0, 2.0, 3.0 or 4.0)?
Or is a PCIe-x2 SATA card where you connect a SSD with a cable to it faster?
Or is a "SSD" SD Card connected via USB even faster?

Memory cards like SD cards are just technically SSD (because SS= Solid State) But are made indifferent scale of transistors, smaller and so potentially less reliable, speed greatly influenced by USB interface which is often much slower than memory itself. Only USB3.2 can make them work full speed.
SATA SSDs are limited by SATA interface which has limited bandwidth to typically 550/500 Mbps.
NVME SSD drives work of PCIe interface which is much faster in frequency as well as in bandwidth.Even PCIe 2nd gen is at least 2 times faster than SATA3 and so are SSDs connected to it.
Newest PCIe gen5 NVME SSDs run at 11.700MBps. Compare that to SATA SSDs. Basically, PCIe interface doubled bandwidth with every generation while SATA will never improve.
So main and deciding difference is in speed but comparing to SD cards also have potential for much greater capacities. Sd cards capacity can't grow as much as other types of SSDs because they are simply limited in size and speed is also limited as faster they are they heat more with no practical way of cooling them while SATA SSDs canbe in metal casing with disapites heat and M.2 NVMe drives can have large evenwater coolers.
In SD cards there's little space to put RAM cache in wich can speed drives considerably.

 

[USAFRet]

If a system does not have native PCIe 3.0 or 4.0 M.2 ports, then get 2.5" SATA III SSDs.

SD cards, wile "solid state" (no moving parts) are NOT even close in performance or reliability.

And of course, getting a Windows system running from USB is its own headache.

 

[Bob.B]

Stupid Question, but why would you prefer one over the other?

Even a 512GB Memory Card is technically a SSD and could be mounted very easy with a card reader into a USB connector. Have WIN and all on it and start it from there (would that even work if USB is the booting device in BIOS)?

So what is better with a "real" SSD SATA (where you need an available SATA connector or a SATA-card (PCIe) where you could plug it in
...vs...
a SSD M.2 NVME (where you also need an adapter to connect it via PCIe)
...vs...
a SD card, connected via USB?

I guess whatever is connected to PCIe is faster than USB.

So is the fastest to get a PCIe-x4 adapter card for M.2 NVME and a SSD card that goes in there? But is the speed not also bottlenecked based on the PCIe (1.0, 2.0, 3.0 or 4.0)?
Or is a PCIe-x2 SATA card where you connect a SSD with a cable to it faster?
Or is a "SSD" SD Card connected via USB even faster?

Other than benchmarks it doubtful you would see a diff in perf between a 2.5 ssd and a nvme ssd.

So just to keep it simple if you have an open sata 3 port on the mobo connect a 2.5 ssd and go.