Question about Samsung's Turbowrite

[dogemaster]

I was reading about Samsung's 850 EVO SSD and just wanted to clarify something. The Turbowrite thing means that data is first sent to the SLC buffer before it is transferred to the TLC part if I'm not mistaken.

So does this mean that Turbowrite is writing the same file twice as in once in the SLC buffer then writing it again to the TLC then erasing it from the buffer?

 

[EasyLover]

Turbowrite was introduced by Samsung in 840 EVO SSDs. With TLC NAND we have first hand problem of increasing latencies. Turbowrite address this issues in a very well manner. By allocating a certain portion of TCL NAND die to act as a buffer to cache the writes, latencies would be hidden. Initial writes are put into this buffer and are written back to the TLC NAND array fast.

With TurboWrite, all writes (not reads) are cached into the buffer (SLC) and from there they are written to the rest of the array. But there is a catch with it, if the buffer is filled, there would be a direct write operation to the TLC, well this is not normally the case. It is only possible if there is a long and sustained write operation.

Samsung is claiming to have more enhanced TurboWrite in 850 EVO with more focus on Random Writes. How? It is still to be seen.

File being written twice. Put it that way: Writing to a 3-bit MLC takes longer than writing to a 2-bit SLC/MLC. So by caching the writes in high speed buffer of 2-bit SLC and during the idle state of the drive, these writes then written to the 3-bit TLC makes much sense here.

Hope this suffices. For more detail plz refer to anandtech as they have covered this topic in detail.

Regards,

 

[dogemaster]

Oh so there are 2 writes, 1 in the SLC cache first then another in the TLC. Thanks!

 

[EasyLover]

Oh so there are 2 writes, 1 in the SLC cache first then another in the TLC. Thanks!

Yes, there are two writes but this should not be taken as something negative because it has been designed in such a way to take advantage of it. Good Luck.