# HP Slate 7 Extreme 16GB Tablet - 7''



## zhong (Aug 1, 2010)

I notice HP Slate 7 Extreme 16GB Tablet - 7'' specs. says it has-

Hard drive: 16GB eMMC, Micro-SDHC up to 32G


So would this type of tablet more easy crash if something goes wrong with the hard drive ?

I mean do other Android tablets which have Nand menory or other type of memory more reliable than tablets which have a hard drive which spins whenever it is doing something on the internal hard drive ?


Thanks


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## Masterchiefxx17 (Feb 27, 2010)

What makes you believe this hard drive spins?

eMMC hard drives are flash based chips similar to NAND.


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## zhong (Aug 1, 2010)

I always thought that hard drives like in P.C., have disks which spin to make programs work and read data. First time I seen tablet's specs. mentioning having a hard drive inside. So I assume we don't need to defrag these so called
hard drives inside the tablets ? These the files inside the hard drives won't get fragmented and we don't need to do a check disk for these hard drives for errors ?

Thanks




Masterchiefxx17 said:


> What makes you believe this hard drive spins?
> 
> eMMC hard drives are flash based chips similar to NAND.


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## joeten (Dec 4, 2008)

In short, no 



NAND - raw flash memory

Raw flash uses its own protocol, and this protocol includes reading pages, writing pages, and erasing blocks. It does not work like disks - disks are able to read blocks and write blocks, flash is able to read and write pages - and a set of pages called a block must be erased before you can write new data. You can only erase a limited number of times before the block wears out and won't fully erase anymore.
SD - "Secure Digital"

It's a memory card format. SD cards contain a tiny microcontroller and NAND. The microcontroller implements a FTL (Flash Translation Layer) that takes disk-like block accesses and translates it into meaningful NAND operations, as well as performing wear-leveling and block sparing. SD cards use the SPI protocol on the "host" side. USB SD card readers convert from USB mass storage commands to SPI SD commands.
eMMC - embedded MMC

This refers to basically what you can think of as an SD card that's built into a motherboard (SD and MMC standards are very similar - enough that SD card readers can typically read MMC cards) - typically soldered in and non-removeable. Typically it is connected to the rest of the hardware via an internal SPI bus. Cell phones and ARM hardware, and other embedded-type devices (i.e. routers) may have this.
SSD - "Solid State Drive"

A controller + a bunch of NAND placed into a hard drive case. The controller implements a FTL (Flash Translation Layer) that takes disk-like block accesses and translates it into meaningful NAND operations, as well as performing wear-leveling and block sparing. Some controller types like "Sandforce", etc. are well known. SSDs use the SATA protocol and connector on the "host" side.

If you are in a situation where you are dealing with raw NAND, such as the Guruplug, you are responsible for doing wear leveling and block sparing. Linux filesystems like jffs2 and such do this, but aren't needed where a FTL does that work like on most SD cards, USB cards, etc


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## Masterchiefxx17 (Feb 27, 2010)

Think of the tablet having an SSD. CHKDSK and Defrag is not needed.


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