eMMC, NAND, and SPI Flash Memory: What are the differences? [LIME2]

[HardDriveStand214]

Hello everyone,
    I am hoping to purchase a LIME2 board from OLIMEX for a home media server but am confused as to what the different models mean.

Can someone here help explain what differentiates each model for the A20-OLinuXino-LIME2 models? Is there a model that is best for home server usage/more powerful?

I immensely appreciate any support/feedback you can provide.

[LubOlimex]

What do you mean by home media server? What media are you going to play? I am not sure if the A20-OLinuXino-LIME2 boards are suitable for playing high bitrate videos. About the questions:

- eMMC and NAND are extra on-board storage. If you need such storage it is best idea to get the eMMC variant - the reason is that NAND is not supported in newer Linux images. The extra storage can be used as general-purpose storage or

- SPI flash is used to assists boot from eMMC. Most LIME2 boards come with SPI flash by default.

You should definitely check this document for more info on what to expect:

https://github.com/OLIMEX/OLINUXINO/blob/master/DOCUMENTS/OLIMAGE/Olimage-guide.pdf

[HardDriveStand214]

>  What do you mean by home media server? What media are you going to play? I am not sure if the A20-OLinuXino-LIME2 boards are suitable for playing high bitrate videos. About the questions:

More of a storage backup sever than anything. As long as I can use it to automatically save files to a USB storage device.

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Is eMMC just like additional storage (as if you were utilizing a USB, SD card, etc.)? Or does it help improve processing power?

Thank you so much for your help. I immensely appreciate it.

[LubOlimex]

eMMC can be used as additional storage, but it can also be used as boot medium (after you run olinuxino-sd-to-emmc it will transfer the Linux from the SD card to the eMMC)

Hard to say if it will improve performance, it would depend on the SD card you are using. Some faster cards might be faster than the eMMC speed. I guess it can be tested empirically just dd some large file and check the average transfer speed when copying the file from one location of the card to another and when writing it from the card to the emmc and when writing the same file from one location of the emmc to another location on the emmc.

By the way you can also attach SSD or hard disk to the board, it can also be used as storage or boot medium. You need a 5V hard disk and this cable set:

https://www.olimex.com/Products/Components/Cables/SATA-CABLE-SET/