I set up the Xavier NX using the Getting Started Instructions on an external SD card and the machine boot-up was fine. However, I cannot find the onboard eMMC disk partition with the
sudo fdisk -l command or the
lsblk commands. I only saw the external SD card, not the onboard 16 GB eMMC.
Am I missing something here or do I need to do something else to access the partition?
As you mention the SD card I assume have the Xavier NX Developer Kit, correct? Only the Xavier NX Module has 16GB eMMC storage.
Developer Kit does not have builtin storage, the SD card is used for that. Dev Kit has a M.2 Key M (NVMe) socket which you can use to increase storage.
Oh, it makes sense, thanks a lot. I didn’t diligently check the two separately and assumed the dev-kit was 100% built on top of the module.
The Xavier NX module with 16G eMMC is sold separately and is even more expensive than Xavier NX Developer Kit (which has NX carrier board + NX module with SD card). I happened to test on both. It seems the 16G eMMC module has 15% better performance than the SD card module. I tested both module with the same Xavier NX carrier board that comes with developer kit.
If you use an nvme or usb SSD as your root filesystem then the sd card performance really doesn’t matter as it’ll only be used by cboot to load the kernel, dtb, and initrd.
I should clarify that the 15% performance difference is not about SSD or SD card. It is the same my AI program running the same Cuda/Cudnn codes that has 15% performance difference. I know SSD/SD should not matter, but then what contribute that difference.
So are you saying that you used an SSD for the root filesystem and tested both SD Card and eMMC versions of the module and the SD Card was still 15% slower?
I tested my AI program on two NX configurations:
 NX module with 16G eMMC + NX carrier board
 NX developer kit, which is NX module with SD card + NX carrier board
The only difference , as I understand, is one has eMMC and the other has SD card. And the AI program runs on configuration , the eMMC one, has 15% better performance.
I don’t believe eMMC or SD card make a difference. I’m wondering if possible the eMMC NX module, which is sold separately, may be somewhat different from the NX module that comes with developer kit.
Ah, now I understand. I also thought the only difference between the two was the storage type. What brand and class SD card were you using? Does your software write logs or dynamically load libraries, etc?
The AI program is mostly cuda/cudnn codes so majority on GPU and some on CPU and throughout the running it doesn’t load or save anything out of the storage (eMMC or SD card) except it loads some files at the very beginning. I use the highest power mode (15W 2CPU) for both tests. I didn’t test on other power modes though.
The system can still be writing logs or something but it is odd. Is swap still set to the zram default?
I’d be curious to see what happens with nvpmodel set to 2 which should be 15W 6CPU.
For the power mode 0, 15W 2CPU, the cpu utilization is very low since most run is on GPU. I chose mode 0 because I wanted to use the highest GPU clock rate. I will try test out on different power mode to see what is the difference.
I was just curious so no need to go to any trouble. Otherwise, I’m not sure what else could cause the slowdown on the SD card module.