I am using a Laptop 16 with the Dual M.2 extension card Under Ubuntu Desktop 22.04.1
So I have 3 nVME SSDs in the system, the 2 WD on the motherboard and 1 Lexar NM790 2TB on the extension card.
I am using my laptop as a desktop, meaning the cover is closed, AC is always on, using external screen (HDMI via laptop port).
Other devices connected are keyboard, mouse, webcam, bar code scanner and infra-red sound remote control; all via a USB (via USB-A laptop port) Dell docking station.
Last is an external 2.5Gb/s RJ45 network interface via laptop USB-C port.
WIFI and Bluetooth are off.
When I benchmark each SSD individually, results comply with SSD specs (between 5000 and 7000 MB/s for sequential load).
The problem is that transferring big ISO files (close to sequential load) from any SSD to any other one (so being on motherboard or on extension card) is limited to a deceptive 1.3GB/s !
Copying my big “Document” tree (close to random small files load), the speed is around 650MB/s (half the speed for random small files looking normal to me).
For copying big ISO files, I was expecting to see something between 4 and 5GB/s as transfer speed.
Is that normal or is there something wrong somewhere ?
You may be running into a similar issue I ran into with my usb4 ssd, benchmarks usually are multi threaded, single threaded coppy can’t saturate the ssd anywhere near as well. Sequential single threaded dd maxed out at a bit under 2GB/s which led me down a whole rabbit hole before I figured out that a multi threaded benchmark saturated the full usb4 link just fine.
In your case all your ssds have their own dedicated pcie4x4 links to the cpu so bandwidth itself should not be an issue. The ssds themselves being the limit is also not likely as they are tlc drives with pretty good native flash speeds so even after the slc cache is full they should be able to do a lot more than 1.3GB/s.
I finally get a Windows To Go to boot Windows 10 and the speed transfer is 2.4GB/s under Windows !
To perform that test, I used 2 nVME SSDs on Dual M.2 adapter, 1 is a gen4 Lexar NM790 (the target of the copy test) and the 2nd is a gen3 Adata SX8200PNP (the source of the copy test) both formatted in NTFS. Given the fact that the source SSD is a nVME gen3, a transfer speed of 2.4GB/s is very good !
I redo the very same test using same SSDs (and same NTFS partitions) but booting Ubuntu 24.04 (not a live key) and the transfer speed was … 1.2GB/s !!!
I think it’s clear that it is Linux that is limiting the transfer speed on my Laptop 16 !
I will update the opened support ticket on that subject.
As mentioned along that conversation, I do the test with Nautilus using cut & paste (not the best but, again, it works fine under Windows).
I used once FreeFileSync but it was also capping at 1.3GB/s …
For me this thread is becoming too long and starts running in circle even if I really appreciate all efforts done so far…
I am now expecting some feedback from the support ticket I opened also.
For me, even if it is not normal, I can work with 1.3GB/s as I, by far, prefer Linux to Windows.
It might be wort trying one of the quite rediculous ammounts of other file managers than nautilus and see if those are faster. I have unfortunately not found one jet that completely covers the feature set of windows explorer that I normally use, gotta hand that to microsoft, it’s a pretty nice piece of software.
I am quite curious what results that is going to yield.
You don’t need special distros you can just install the file managers separately, there is a ton of them though and finding one you like may be somewhat difficult. I tried myself through a bunch of those last year and I do remember some having settings for multithreaded copy.
I can find multithreaded download file manager but no indication for local file manager.
I will investigate backup tools… This speed limitation looks crazy and frustrating to me…