[SOLVED] sata gb/s

[EJ Morin]

what is sata gb/s vs normal gb/s

 

[Darkbreeze]

What?

What do you mean by "normal"? Normal WHAT? SATA "IS" normal for most storage devices. PCI/NVME would be the more exotic option.

Your question is very unclear and more information will be required.

 

[mdd1963]

the spec often calls it 6 Gbps...(which, divided by 8 to get bytes, makes it 'sound' like 750 MB/sec would seem routine)

Real world operation, if you ever see a quality SATA SSD exceed 563 MB/sec sequential reads in CrystalDIskMark...let me know!

 

[Darkbreeze]

I don't actually think that is what he is asking, but since his question was about as clear as mud, who knows?

 

[EJ Morin]

I don't actually think that is what he is asking, but since his question was about as clear as mud, who knows?

They say SSD drives with SATA are slower than M.2 drives. When I searched for information on the M.2 drive, it said it transferred a maximum of 3 GB/s. Because of this, and the notion that SATA is slower, I came to the conclusion that SATA Gb/s were slower, and different.

P.S. I am just trying to learn more about this subject. Sorry that the question was unclear, but I would never learn if I didn't ask questions.

 

[USAFRet]

They say SSD drives with SATA are slower than M.2 drives. When I searched for information on the M.2 drive, it said it transferred a maximum of 3 GB/s. Because of this, and the notion that SATA is slower, I came to the conclusion that SATA Gb/s were slower, and different.

P.S. I am just trying to learn more about this subject. Sorry that the question was unclear, but I would never learn if I didn't ask questions.

"They say..."
"They" are quoting misinformation and incorrect terminology.

"M.2" is not a determinant of performance. It is simply a form factor....how the thing plugs in.
There are SATA III drives in both the 2.5" format and M.2 format. Exactly the same performance, just in a different package.

NVMe drives, which are often in the M.2 package, are the faster ones that are referred to.

 

[Darkbreeze]

They say SSD drives with SATA are slower than M.2 drives. When I searched for information on the M.2 drive, it said it transferred a maximum of 3 GB/s. Because of this, and the notion that SATA is slower, I came to the conclusion that SATA Gb/s were slower, and different.

P.S. I am just trying to learn more about this subject. Sorry that the question was unclear, but I would never learn if I didn't ask questions.

There is nothing wrong with asking questions. Ever.

But, when you ask, you need to be sure to make it VERY CLEAR what it is you are asking, not just a couple of vague words, so that somebody will have no trouble knowing what the question actually IS. If that means you need to write three or four sentences to spell out exactly what you want to know, then do that.

As USAFRet has already indicated, M.2 has nothing to do with the speed. M.2 is ONLY the "shape/form factor" of the drive and how it plugs in. It is nothing whatsoever to do with speed.

The speed is determined by whether it is an SATA, PCIe or NVME device. PCIe and NVME devices are SOMETIMES much faster than a SATA device, but not always. In some cases, for most normal use scenarios like random reads and writes, it is no faster than a SATA drive. Other times, for sequential reads and writes, especially when it's a single large file, it is much faster.

And to answer your question there ISN'T any "SATA vs Normal" speed comparison that is black and white, because it will be totally different speeds based on the specific drive being used, WHAT is being read or written, what the speed of BOTH devices are and even where those devices are connected to on the motherboard or in some cases, via an external USB connection.

 

[Maxxify]

Check the link in my profile.

To be short:

SATAIII is 6 Gbps, that is 768 MB/s, which after 8b/10b encoding and overhead is approximately 550 MB/s. NVMe drives using PCIe 3.0 are limited to four lanes of 8 Gbps, which after 128b/130b encoding and overhead is approximately 3600 MB/s. This only refers to sequential speeds.

 

[Darkbreeze]

Right. And it's important to note for the uninitiated that sequential speeds are rarely seen. Most often you will see some combination of sequential and random reads and writes, which are much slower than those advertised speeds, and usually, for most day to day usage, just random reads and writes, which is magnitudes slower in real world usage.

Plus, those very fast NVME and PCI drive write speeds are only going to happen if you are writing to AND from a device of equally capable speed limits. If you are writing from your NVME/PCI drive to a SATA drive, you will be limited to SATA speeds, and visa versa.