Good news!
I got it up and running (I think) …
With your help! So thank you!
Only issue now is, when I try to boot from the ssd, it does nothing.
The only mode where petit boot recognizes the ssd at all is in spi mode. (Petitboot still boots in mmc boot however the ssd does not pop up)!
The ssd device (labelled sda1) has coreelec flashed to it with rufus. Emmc is not attached. Mode is in spi.
Thank you again!! 
Congratulation!! Let’s do another update…
Download the file and copy it to your MMC card as spiboot.img before reboot, then Petitboot will load and update itself. Do not flip the boot select switch to MMC, keep at SPI. Once everything is done, on next reboot you will see the new version 20190705 and it will load from SSD.
You are a life saver!
Everything is up and running now! Booting from my ssd thru usb 3 !!
Thanks again for all the help!
One small note for any one interested,
The performance is much worse than emmc. In fact kodi bogs down quite easily on the ssd via USB.
I ran i/o benchmark in kodi, and it shows performance as slightly worse than the emmc.
I also copied a large file within each drive. The emmc performs at a rock solid fixed 45-147 MBps, while the SSD starts at 230 for about 1 second then drops to 100 quickly, then down to 60, back up to 100, etc.
Not sure if this is a limitation of usb 3 or my ssd?
I’m using the Samsung evo 840, which isn’t bad.
Looking at odroids own data, it shows usb 3 theoretical 4k/16k/512k as slightly better than emmc.
If you boot from eMMC,using your SSD as a plain external drive, do you get a performance increase when copying to the SSD?
And just to make another potentially useful comparison, carry out the same file copy test with the SSD connected to a port on your PC.
The N2 specs show the use of a GL3523 USB 3.0 controller, which looks good on paper.
As a slight aside, I reckon that it would be great if you packed all the information into a step by step guide and posted it onto the Guides and How-tos section of the forum for others to follow for future use.
Try to use the Micro-USB OTG, maybe it performs better.
see https://forum.odroid.com/viewtopic.php?f=181&t=34849
There were some issues esp. with the GL3523 USB HUD, see HK forum…
@tobetter:
https://forum.odroid.com/viewtopic.php?f=181&t=34849&start=100#p262780
What was the outcome of the HW review?
From my point of view, after reading the datasheet, I agree to “nick793” that your implementation may be causing brownout on 1V2 rail for load regulation due to SMPS reg. limits.
Please let me have the output of cat /proc/cmdline when you do copy with SSD.
Just to confirm what you are requesting that I test:
on N2 :
SSD to SSD copy (booting from ssd)
eMMC to SSD Copy (booting from eMMC)
SSD to eMMC copy (booting from eMMC)
eMMC to eMMC copy (booting from eMMC)
It wont actually let me boot into ssd, and access the emmc as a storage drive. Because of this I cant test SSD to eMMC copy (booting from SSD).
On PC :
internal SSD (Windows PC) to external SSD (COREELEC) copy
external SSD (COREELEC) to internal SSD copy (Windows PC)
Let me know if all that will be sufficient to better determine a potential issue. If it is not all necessary, which from (1)-(7) shall I test?
Where exactly am I looking for : cat /proc/cmdline , on my N2? or Windows PC? Can you further explain how I would go about accessing this for you?
Thanks again for all the help
OK, then initially, do the basic tests.
Connect the SSD to your PC through the USB 3.0 port and test the average copy speed of your chosen large file. This just verifies that the transfer speed is capable of meeting your expectation.
Then boot the N2 from eMMC, connecting the SSD through one of the USB 3.0 ports and carry out the same test of copying the same chosen large file from eMMC to SSD (t might even be potentially useful to test the copy from all 4 USB 3.0 ports).
It gives you a baseline from which to start further testing and can help to immediately reduce the potential culprit(s), in this case, your SSD/Connection combo.
Where exactly am I looking for : cat /proc/cmdline , on my N2? or Windows PC? Can you further explain how I would go about accessing this for you?
You can run the command in the command shell on N2.
Just for clarification @tobetter
So first you want me to perform a copy from ssd to ssd , booting from ssd (coreelec) on n2
immediately after the file is copied, type
cat /proc/cmdline
by SSHing into device.
You can type the command any time, I just want to get the output with the command to find out a kernel parameter since you are experiencing slow I/O throughput. If you do not have any issue to use SSD on N2, you don’t need to type the command.
I plugged the SSD into my windows PC to test speed of copying a test file. however the main storage partition is not viewable by windows? I cant assign a letter to the drive like I was able to with the COREELEC partition (only 512mb)
How could I go about testing this with the way the drive is setup for booting COREELEC on my N2?
The partition - ext2/3/4 - won’t be visible by Windows, so cannot perform the I/O test.
What’s your issue now? I thought you are able to boot from SSD and now the problem is that I/O performance in SSD is poor.
Thanks for clarifying.
I was trying to get to Compent’s request.
I will send you the report cat /proc/cmdline
Here is what shows after two i/o benchmark runs (about 10 seconds each).
cat /proc/cmdline
Thanks again tobetter!!
I’d just format the drive to test.
You could boot it to CE in order to make a backip to restore later.
So now messing around with the ssd as a boot drive again , things feel snappy. No bogging down what so ever. I/o benchmark is even performing better than emmc now. (Ssd to ssd VS ssd to emmc or emmc to emmc)
Some results strictly using N2:
Copying a 4 GB .ts file. (Excluding initial bursts as they are for 1-2 seconds only)
Ssd to ssd : around 110 Mbps (85 min / 175 peak)
Ssd to emmc : 65 Mbps (57 min / 208 peak)
Emmc to emmc : 37 Mbps (35 min / 140 peak)
The speeds seem quite low compared to what is advertised, although no “bogging” down of system – which required hard reset.
I’m not sure what happened? The “bogging” down was occurring consistently last night while using the ssd as a boot drive.
It is no longer occuring.
It’s good that you have no bogging down but if those speeds are representative of the USB 3 port performance on the N2 then I’d be very disappointed.
This is what I am trying to figure out … It seems far too low for a large file copy. Although so is the emmc copy speed for this file. I will do more testing tomorrow with windows and compare.
Id like to mention the speed always has a spike initially, and then a steady drop, plateauing at near the minimum speeds I posted after only 30 seconds.
I also think I am using a different usb port than yesterday. Other than that nothing has changed other than latest nightly. I have not yet experienced “bog” down that I had yesterday.
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