M.2 SSD NVMe Support

[oshunluvr]

My desktop is a Frankenstein monster of storage: 1 NVME, 2 SSDs, 2 HDs.

The transfer rate differences: SSDs are 4 fold faster than the HDs and the NVME is 5 fold faster than the SSDs.

[Qqmike]

yeah, guys, that's how things are evolving. Notwithstanding the use of "old" slower SATA lanes (SSDs); notwithstanding the clear and outrageous speed performance of M.2 vs SATA SSD vs HDD ... fact is, (1) HHDs are still in demand for cheap, mass storage; (2) SATA SSDs are still very popular, the most popular. Of course, it helps to have a motherboard ready for M.2 ;-). Another thing to watch is USB-C and re-naming of USB standards, and all that. Main thing there is your case: front panel connectors to the case ... versus, I guess ... back I/O connectors that carry various USB spec-ports (and could be routed to the front maybe with adaptors etc or simply with a cable on your desk!). I usually build DIY and forget it. This time, after this build, I'm gonna try to keep up with things. Easy to do by reading or simply scanning quickly the emails sent by Tom's et al.

[oshunluvr]

Another thing on the home builds - unless you're using a ton of PCIe lanes, you can get a mini-itx board and have a smaller overall footprint.

My yardstick on my last build was to have 2 NVME slots so I could RAID them, LOL. I never got around to buying a second NVME drive because I just didn't need more speed. I have been eyeing an upgrade to a faster CPU but my current system isn't faltering so I guess I'll just wait it out for awhile longer. I watch my CPU usage and see a lot of single core peaks during many operations so I've decided a very high performing singe core is worth more to me than multicore performance. I have an AMD Ryzen 7 5800X saved in my Amazon cart because it scored the best single core performance per dollar that I could find. However, since it also means a new mobo and RAM and waterblock it's quite an investment.

[oshunluvr]

Correction: I just learned the Intel 11th gen i9 supports PCIe 4.0 and has a slightly higher single core performance than the 5800X - at a higher price tag of course.

[GreyGeek]

FYI, NVME on PCIe 4.0 (AMD only boards at this point) are about 25% faster than 3.0. Still 3.0 here:

stuart@office:~$ sudo hdparm -tT --direct /dev/nvme0n1

/dev/nvme0n1:
Timing O_DIRECT cached reads: 4200 MB in 2.00 seconds = 2101.42 MB/sec
HDIO_DRIVE_CMD(identify) failed: Inappropriate ioctl for device
Timing O_DIRECT disk reads: 8348 MB in 3.00 seconds = 2782.57 MB/sec

NVME's are significantly faster than SSD's.

Guess which one is my Toshiba spinner with 16 bad sectors:

[FONT=monospace][COLOR=#000000]$ sudo hdparm -tT --direct /dev/sdX1[/COLOR]
  

/dev/sda1: 
 Timing O_DIRECT cached reads:   930 MB in  2.00 seconds = 464.52 MB/sec 
 Timing O_DIRECT disk reads: 1466 MB in  3.00 seconds = 488.20 MB/sec 
[/FONT]
[FONT=monospace][FONT=monospace]/dev/sdb1: 
 Timing O_DIRECT cached reads:   180 MB in  2.01 seconds =  89.58 MB/sec 
 Timing O_DIRECT disk reads: 304 MB in  3.00 seconds = 101.28 MB/sec 
[/FONT]
/dev/sdc: 
 Timing O_DIRECT cached reads:   504 MB in  2.00 seconds = 251.88 MB/sec 
 Timing O_DIRECT disk reads: 780 MB in  3.01 seconds = 259.54 MB/sec [/FONT]

The primary is a Samsung EVO 860 500Gb SSD. It has a boot sector and was formatted with BTRFS @ as / and @home as /home, at first. Then I merged @home into @.

The second SSD is also a Samsung EVO 860 500Gb. I just formatted it entirely as a BTRFS subvolume, with no mount point.

The claim for the Samsung EVO 860 500Gb drive is

Enhanced read write speeds: Sequential read and write performance levels of up to 550MB/s and 520MB/s, respectively

I'm getting roughly 90% and 47% of rated maximum on my two 860's. The difference is that sda1 partition was formatted as /. Sdc was formatted as BTRFS directly without creating a partition. I don't know if that accounts for its slowness, but it is something I'll probably investigate by reformatting it and creating an sdc1 partition.

My sda1 has been powered on 465 days and 17 hours, is rated to last at least another 1,000 days, and has written 17.26TB.
It has one temperature warning on it, at 53C.

My sdc has been powered on 281 days and 1 hour, is rated to last at least another 1,000 days, and has written 1.26TB. There are no warnings.

I use sdc only as a repository for BTRFS differential backups, which usually takes around 30 seconds from a Konsole. I usually am doing something else while that process takes place.

[jglen490]

yeah, guys, that's how things are evolving. Notwithstanding the use of "old" slower SATA lanes (SSDs); notwithstanding the clear and outrageous speed performance of M.2 vs SATA SSD vs HDD ... fact is, (1) HHDs are still in demand for cheap, mass storage; (2) SATA SSDs are still very popular, the most popular. Of course, it helps to have a motherboard ready for M.2 ;-). Another thing to watch is USB-C and re-naming of USB standards, and all that. Main thing there is your case: front panel connectors to the case ... versus, I guess ... back I/O connectors that carry various USB spec-ports (and could be routed to the front maybe with adaptors etc or simply with a cable on your desk!). I usually build DIY and forget it. This time, after this build, I'm gonna try to keep up with things.

Easy to do by reading or simply scanning quickly the emails sent by Tom's et al.

I will say that my external backup drives are HDDs and they work fine for that. It takes 30 minutes or so to back up 260GB, but with the good Ugreen enclosures I can watch a couple innings of baseball without worrying. It's all good

[Qqmike]

jglen, yeah, I don't think anyone has given up production of HDDs; seems there are new products there. Ditto for SSDs. Nothing wrong with it, sounds like a good storage solution.

[Beerislife]

I'm thinking about replacing the 1Tb HDD that came with my machine with a 1Tb (or more) SSD... Just thinking... ��

[claydoh]

So am I, but I spent the same amount on a keyboard , then a bigger monitor.
I wish my PC or laptop had dual nvme slots, I'd add a smaller one and keep the 2Tb 7200 hdd the el cheapo refurb HP Pavilion came with. It is 7200rpm , and is actually faster and quieter than I would have thought.
I really need a 2Tb ssd, and those are still $$$. no matter what form factor.

[Beerislife]

Yeah, a 1Tb Crucial is 11,780 yen (No idea what that is in your currency) and the 2Tb model jumps to 24,580 yen. Cough, cough, choke!

When my 27" monitor died I only had the funds to replace it with a cheap Dell 24" IPS screen (About the same price as a 1Tb Crucial SSD!)

I'm in a slightly better position now and chomping at the bit for a bigger monitor for X-Plane! But the boss would not be amused if I bought one while this one still works!

[Beerislife]

I'm looking at this Dell 27" curved screen...

https://is.gd/twQbhD

[GreyGeek]

To save people the time of looking it up ....
11780 yen = 108.26 USD
24,580 yen = 225.90 USD

And ya, $225 would choke my budget as well...

[Qqmike]

Device name with M.2

(1) With this device name: /dev/nvme0n1p2 ...
n1 = device 1 = "drive" 1
p2 = partition 2
(so, we might think of this as we would think of sda2)

Correct?

(2) So what is the zero following nvme: /dev/nvme0n1p2

(3) With two M.2 cards, we'd have /dev/nvme0n2pn. n some positive integer. Correct?

(4) Anyone have a system with two M.2's? Can you run df -hT?

(5) Anyone have a mixed system, SATA SSD's and M.2's, and run df -hT (maybe oshunluvr).

Thanks. I've googled until I'm silly, not finding much on this. Of course M.2 is still so new, that there are not too many examples of complicated/mixed systems yet. I haven't carefully checked Rod Smith's site; he'd know all about this, but maybe has not yet documented anything.

[Snowhog]

What my Google foo found:

The NVMe naming standard describes: nvme0: first registered device's device controller. nvme0n1: first registered device's first namespace. nvme0n1p1: first registered device's first namespace's first partition.

[Qqmike]

Snowhog, I think you got it. Reading your post, it occurred to me that I really don't understand "namespace."
Google on "namespace," get lots of stuff, like this:
https://nvmexpress.org/resources/nvm...me-namespaces/
from which, this clip:

In Linux, namespaces appear each with a unique identifier in devices; /dev/nvme0n1 is looking at controller 0 and namespace 1).

Thus, the 2nd controller would be a "1," and so on. I don't yet get it fully, need to study "controller," but I think it's all there, somewhere, under the subject 'Linux namespaces.'

Too pooped tonight, but will pursue this later. Thanks, Snowhog! Think you nailed it.