Sandisk Claims Hundredfold Flash Speed Increase


Step 1) remove several layers of unnecessary software bloat/hacks *hooray an actual improvement*
Step 2) invent new stupid formula because stupid people can't see the difference between HDD and SSD *actually that's 2 different letters*
Step 3) claim victory for step 2 instead of step 1 * euh wtf :unsure: *


title should have said, "sandisk finally finds opportunity to get rid of 100X bottleneck* in my opinion
 
I'm glad for the new tech, but I want to know when those Sandisk 32gb SDHC cards will be available.
They were announced in early 2008 and still nada anywhere. :(
 
That article just doesn't sound right. "most operating systems and filesystem drivers expect for a mass storage device to be structured like a hard disk, i.e., addressable using cylinders and sectors.". I've examined how both Linux and Windows talk to standard USB sticks, SD cards, etc, and it doesn't talk that way to any of them. The only thing I've ever noticed is that a lot of drives state they have a 512-byte sector size, whilst in reality it's between 4KB and 16KB, but this is typically taken care of by the controller built into the USB stick/etc.

"In the case of ExtremeFFS, this OS-to-physical mapping is not static. Rather, the controller and software work with the flash to do dynamic mapping". It never has been static to my knowledge, the logical to physical translation tables have always been dynamic - thats how wear levelling works. Each time a block is written, the table is changed so that a different physical block is written next time.

"ExtremeFFS can also do a few more tricks, like doing housekeeping and garbage collection chores (marking bad blocks and actually erasing blocks marked as "empty")". I'd like to see how it knows which blocks are actually empty, as no OS I know actually marks or erases blocks when a file is deleted, just marks the blocks as available in the allocation table, which the flash controller knows nothing about, as it doesn't have a clue which file system you are using.

It all seems like Sandisk have just come up with yet another file system that is supposed to be optimised for flash based media.

Or maybe I don't fully understand what they are trying to get at.
 
@Squidge well that is interesting I had always heard taht flash emulates the HD interface as it says... I've never heard otherwise

normally the OS has nothing to do with the wear leveling afaik since that is handled by the chip itself.

also you know there are several kinds of flash... the slower kinds having slower write speeds due to storing data in a different and more compact manner (but the OS doesn't care or know this) .... i think it is by being able to write multiple bytes in the same area of flash (just looked it up called multilevel cell tech.)


also Linux flash file systems mostly implement caching techniques.... since reading from flash is good but it is best to reduce the number of w.. strike that

wikipedia states what i was trying to say better http://en.wikipedia.org/wiki/Flash_memory#Flash_file_systems

read the bottom paragraph about flash filesystems
 
cb88 said:
@Squidge well that is interesting I had always heard taht flash emulates the HD interface as it says... I've never heard otherwise
Compact Flash cards can emulate IDE harddisks, but every other flash technology I've seen uses a pure sector (no cylinder or head) format. Actually, thinking about it, harddisks don't use cylinder/head anymore either - they use LBA, which is a simple "get me sector X", just like on flash media, so they are very similar, just not like the article says.
cb88 said:
normally the OS has nothing to do with the wear leveling afaik since that is handled by the chip itself.
Yes, I agree. Smartmedia (basically controllerless nand) requires it in software if you want the card to be readable elsewhere, and I remember writing such libraries for it (on the GP32). One of it's speed up tricks was actually using contiguous sectors (on the physical side) rather than the more usual random ones, so maybe I thought about it before Sandisk did - I should have patented the idea :DQUOTE
also you know there are several kinds of flash... the slower kinds having slower write speeds due to storing data in a different and more compact manner (but the OS doesn't care or know this) .... i think it is by being able to write multiple bytes in the same area of flash (just looked it up called multilevel cell tech.)
I didn't think there was different kinds of flash, but rather the same flash, but different controller. QUOTE
read the bottom paragraph about flash filesystems
Will do, thanks.
 
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