Can I say thank you 8 years after the fact? 😐

Can I say thank you 6 years after the fact 🙂

Q1: In Figure 2 (Row-4,Col-4), you mark C1 & C2 for GC and take away overprovisioning space. In Figure 3 (Row-4,Col-4) however, you again mark C1 & C2 for GC, but do not take space away from overprovisioning. They both look pictorially identical to me (except for the cell color of GC). Could you please better elaborate the difference between the two?

Q2: In Figure 2 (Row-4,Col-4), the overprovisioning space reduces and free space remains constant. Is it because in your example overprovisioning is assigned from available free space & not a dedicated memory for overprovisioning?

Q3: For a Non-TRIM architecture, at what point will the SSD know that the data is invalid and hence can be considered as Free Space?

Q4: Lastly, just a clarification: I understand each cell in Figure 2 & Figure 3 (A1, A2 etc.) to be a Block and not a Page. Is that correct?

Q1: In Figure 2 (Row-4,Col-4), you mark C1 & C2 for GC and take away overprovisioning space. In Figure 3 (Row-4,Col-4) however, you again mark C1 & C2 for GC, but do not take space away from overprovisioning. They both look pictorially identical to me (except for the cell color of GC). Does this mean that at this point, the SSD knows the data is invalid in both cases? If yes, why isn’t it considering it as free space during GC in bith cases? Could you please better elaborate the difference between the two?

Q2: In Figure 2 (Row-4,Col-4), the overprovisioning space reduces and free space remains constant. Is it because in your example overprovisioning is assigned from available free space? If a dedicated portion of memory is set aside for overprovisioning, I would expect the free space to reduce, unless at this point SSD controller considers C1 & C2 as free space (because it already marked the blocks for GC). Could you please clarify?

Q3: If for Q1 above, the answer is that in Figure 2 (Row-4,Col-4), the SSD does not know C1 & C2 is invalid and therefore will re-write invalid data during GC, could you please elaborate at what time will the SSD know the data is invalid in a Non-TRIM architecture?

Q4: Lastly, just a clarification: I understand each cell in Figure 2 & Figure 3 (A1, A2 etc.) to be a Block and not a Page. Is that correct?

Q1: In Figure 2 (Row-4,Col-4), you mark C1 & C2 for GC and take away overprovisioning space. In Figure 3 (Row-4,Col-4) however, you again mark C1 & C2 for GC, but do not take space away from overprovisioning. They both look pictorially identical to me (except for the cell color of GC). Does this mean that at this point, the SSD knows the data is invalid in both cases? If yes, why isn’t it considering it as free space during GC in bith cases? Could you please better elaborate the difference between the two?

Q2: In Figure 2 (Row-4,Col-4), the overprovisioning space reduces and free space remains constant. Is it because in your example overprovisioning is assigned from available free space? If a dedicated portion of memory is set aside for overprovisioning, I would expect the free space to reduce, unless at this point SSD controller considers C1 & C2 as free space (because it already marked the blocks for GC). Could you please clarify?

Q3: If for Q1 above, the answer is that in Figure 2 (Row-4,Col-4), the SSD does not know C1 & C2 is invalid and therefore will re-write invalid data during GC, could you please elaborate at what time will the SSD know the data is invalid in a Non-TRIM architecture?

Q4: Lastly, just a clarification: I understand each cell in Figure 2 & Figure 3 (A1, A2 etc.) to be a Block and not a Page. Is that correct?