Performance VS Transfer Size

Intel's 3D XPoint memory is not bound by the page and erase block structure of NAND flash. Intel hasn't disclosed what the native word size of the 3D XPoint memory array is, but the Optane SSD DC P4800X as a whole is optimized for 4kB or larger transfers. Real-world I/O isn't always constrained to just the 4kB and 128kB transfer sizes most of our synthetic benchmarks use, so the next several tests look at single-threaded QD1 performance of transfers ranging from a single 512-byte sector up to 1MB blocks. For random reads and writes, the impact of issuing commands with suboptimal alignment is also considered. Depending on how a drive is organized internally, unaligned accesses can significantly increase the amount of work the controller needs to do.

Random Read
  Vertical Axis scale:
Block Aligned Linear Logarithmic
512B Aligned Linear Logarithmic

The random read performance of the Optane SSDs is completely beyond the reach of the flash based SSDs, even for large block sizes. Even when the reads aren't aligned to the block size or to the drive's preferred 4kB alignment, performance is still great until the block size reaches 128kB, the largest the Optane SSD can transfer from a single command. At that point, the Optane SSDs slow down slightly before performance continues to grow at a more moderate pace.

Random Read
  Vertical Axis scale:
Block Aligned Linear Logarithmic
512B Aligned Linear Logarithmic

The random write performance of the Optane SSDs is not much better than the Intel P3700, especially for writes smaller than 4kB. The Intel P3608 and Micron 9100 MAX are slower across the entire range of block sizes. For unaligned writes of larger block sizes, the Optane SSDs hit a hard limit at around 1.3GB/s while properly aligned writes can approach 2GB/s for large blocks.

 

Random Read
Vertical Axis scale: Linear Logarithmic

The Intel P3700 delivers a slightly higher QD1 sequential read throughput for small block sizes, likely due to the controller caching whole NAND pages in RAM. At the larger block sizes more typically used for sequential I/O, the Optane SSDs are on top and the many of the flash-based SSDs cannot reach full performance without going beyond QD1.

Random Read
Vertical Axis scale: Linear Logarithmic

None of the SSDs perform particularly well for writes smaller than 4kB, but the Optane SSDs do have a clear advantage. As transfer size grows, the Optane SSDs pick up speed faster than the flash-based SSDs. The Intel P3608 is the first to start hitting a performance ceiling, while the Micron 9100 is almost able to catch up to the Optane SSDs.

Fine Tuning Performance Single-Threaded Performance
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  • woggs - Thursday, November 9, 2017 - link

    This drive is PCIe 3, so nothing will change because it will link as gen 3. Will need a whole new drive... Reply
  • MajGenRelativity - Thursday, November 9, 2017 - link

    I believe OP was talking about a drive that was identical to this in every way, but supporting PCIe 4 Reply
  • woggs - Thursday, November 9, 2017 - link

    And SSD is a system and would neither over nor under engineer any one piece significantly. So, altering one piece should not be expected to suddenly pop to some much higher performance. Will require a whole new drive. Reply
  • Hurr Durr - Thursday, November 9, 2017 - link

    Where is requisite ddriver hysterics session about hypetane? Reply
  • Reflex - Thursday, November 9, 2017 - link

    It appears the hysteric is gone at least for the time being. As a result the discussion has been far easier to read.

    Great drive, can't wait to see future generations where presumably they will increase density and reduce power consumption...
    Reply
  • woggs - Thursday, November 9, 2017 - link

    Yep! Reply
  • woggs - Thursday, November 9, 2017 - link

    (on both counts) Reply
  • Hixbot - Thursday, November 9, 2017 - link

    He must be taking the day off. I'm sure he'll flood the comments tomorrow. Reply
  • Makaveli - Thursday, November 9, 2017 - link

    If you say his name 3 times he will show up....

    DON'T DO IT!
    Reply
  • abhaxus - Thursday, November 9, 2017 - link

    I came here looking for him, and was disappointed. Reply

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