Comments

• Vrika Member LegendaryPosts: 7,990

  February 2019 edited February 2019

  There are differences in performance between drive sizes for all SSDs of same series no matter what series you pick. For example the competitor 970 EVO plus 250 GB is specced to write only 400 MB/s after its write buffer is full, but 970 EVO plus 1 TB is specced to write 1 700 MB/s after its write buffer is full.
  
  More SSD space equals more parallelization, which equals faster speeds.

  

   
• Beezerbeez Member UncommonPosts: 302

  February 2019

  Long-standing. For several years.
  I kid, I kid. I love these kinds of write-ups. Thanks and keep up the good work.
• Pastor_Dame Member UncommonPosts: 37

  February 2019

  
  

  Vrika said:

  
  

  There are differences in performance between drive sizes for all SSDs of same series no matter what series you pick. For example the competitor 970 EVO plus 250 GB is specced to write only 400 MB/s after its write buffer is full, but 970 EVO plus 1 TB is specced to write 1 700 MB/s after its write buffer is full.
  
  
  
  More SSD space equals more parallelization, which equals faster speeds.

  
  

  
  
  Appreciate your insight!
  
  I felt like it was noteworthy since the performance drop in the smaller drivers seemed to be great than other drives within a similar family. A great example of this would be the new 970 EVO Plus from Samsung. The performance of the 250GB model is great with slight improvement across the series as in the drives increase in sizes. When comparing the difference in drive performance between the 970 EVO Plus and the WD_Black SN750, the dip in performance seemed to be more drastic in the WD_Black at lower capacity. This could be the difference between how performance scales differently between 64-layer 3D NAND and 9x 3D NAND - much like you stated: More parallelization.
  
  As far as I can tell, Samsung seems to be the first to bring 9x 3D NAND to the market. It will be interesting to see if this proves true across the board.
  
  

  
  

  Beezerbeez said:

  
  

  Long-standing. For several years.
  
  I kid, I kid. I love these kinds of write-ups. Thanks and keep up the good work.

  
  

  
  
  Hahaha - Thank you so much for the encouragement!
• Quizzical Member LegendaryPosts: 25,499

  February 2019

  The performance drop from smaller drives is because they have fewer NAND flash chips, and thus, less parallelism available to access them.  That's the way it has always been for SSDs, though whether there is a performance drop (and if so, how large) varies based on a lot of factors.
  
  It's analogous to how if you have an eight core CPU and run a program on it, you'll get some level of performance.  If you disable four of the cores, then depending on various circumstances, it might give the same performance as before, or it might give less.  If you disable six cores, that may or may not further decrease performance as compared to four.  Whether it actually will decrease performance or not in a given workload depends on a lot of factors.