How fast is eMMC compared to an SSD?

Discussion in 'Hardware' started by Peon, Feb 19, 2015.

  1. Peon

    Peon Pen Pal - Newbie

    Messages:
    11
    Likes Received:
    0
    Trophy Points:
    5
    People often compare SoC performance to that of the venerable Core 2 Duo, so I'm wondering if there's a similar analog for eMMC performance. Is eMMC nowadays as fast as, let's say, a:
    • Samsung RBX?
    • Intel X25-M?
    • Crucial M4?
    • Plextor M5P Xtreme?
    • Samsung XP941? (yeah, right :vbrolleyes:)
     
  2. alicepattinson

    alicepattinson Scribbler - Standard Member

    Messages:
    171
    Likes Received:
    7
    Trophy Points:
    31
    I have both but I don't see huge difference of the 2. :)
     
  3. Mesosphere

    Mesosphere Geek. Senior Member

    Messages:
    5,252
    Likes Received:
    1,906
    Trophy Points:
    331
    Some of the better ones are almost as good as Samsung RBX (based on the benchmarks I can dig up on that ancient thing =P)
     
  4. ships10

    ships10 Scribbler - Standard Member Senior Member

    Messages:
    1,515
    Likes Received:
    171
    Trophy Points:
    81
    Any definitive answers to the question ....eMMC Vs SSD
    benchmarks?
     
    Last edited: Mar 23, 2015
  5. Mesosphere

    Mesosphere Geek. Senior Member

    Messages:
    5,252
    Likes Received:
    1,906
    Trophy Points:
    331
    Where one sees the biggest differences is in the small random IO operations. The OS and running programs do lots of little reads and writes to config files and such during operation and this can cause significant and noticeable slow downs for eMMCs. For SSDs they have IOPS of ~50k-200k. For eMMC your looking at ~3k-8k. So these small IO operations are around 6-60x slower for an eMMC. Most of the time when you experience the little hangs here and there you have probably run into an IO bottleneck not a CPU bottleneck.

    Things are a little bit better for sequential reads/writes (think saving/loading a big file). SSDs are typically around 250-500 MB/s (sometimes even faster). For an eMMC the speeds are in the 50-150 MB/s range. So ~2-10x faster for SSD.
     
    sonichedgehog360 and Ed Hardy like this.
  6. ships10

    ships10 Scribbler - Standard Member Senior Member

    Messages:
    1,515
    Likes Received:
    171
    Trophy Points:
    81
    Thanks Meso.....that's very helpful to know .
    Do you think SSD's could be sordered on to the motherboard
    in small enough size and weight in a cost effective way
    to make them readily replace eMMC's?
     
  7. yuki

    yuki Scribbler - Standard Member

    Messages:
    187
    Likes Received:
    87
    Trophy Points:
    41
    sata, m2, emmc - all kinds of ssd are not noticeably different in size.

    emmc being the slowest, sata mid-range, m2 & other pciedirect attached the fastest - all of them outperform harddisk and allow a good user experience.
     
  8. Mesosphere

    Mesosphere Geek. Senior Member

    Messages:
    5,252
    Likes Received:
    1,906
    Trophy Points:
    331
    Basically true, but HDDs are faster than eMMC for sequential reads. Most of the time though, that isn't the metric that affects user experience.

    Still, while being much faster than HDDs in terms of IOPS, I find the downgrade in IOPS from SSD to eMMC to be highly noticeable. It performs well enough that I am willing to live with it, but it is the biggest problem I have with the Bay Trail SOC.
     
  9. yuki

    yuki Scribbler - Standard Member

    Messages:
    187
    Likes Received:
    87
    Trophy Points:
    41
    No, that is incorrect.

    The emmcs as in vivotab note 8 etc easily deliver 130, 140 mbyte/sek sustained sequential read - quite faster than the average hdd.

    They are slower in sequential -write- however.

    For my use cases (film, video, photo mainly) i cant confirm that.
    Doing copies of large quantities of RAW-images, editing video etc all demands for high sequential read&write more than anything else.

    You are SPOILED! :)

    hehe, yeah, often emmc-ssd vs sata-ssd is the main difference.

    However, its not a limit of the baytrails, baytrail -does- support sata-ssd:
    http://www.legitreviews.com/intel-nuc-dn2820fykh-bay-trail-system-review_135053/2

    its the choice of the manufacturers - not a limit in the architecture.

    If you sell +- 10.000.000 tablets alone a year, $10 less for emmc-ssds instead of sata(or m2)-ssds adds another 100.000.000$ profits.
     
  10. Mesosphere

    Mesosphere Geek. Senior Member

    Messages:
    5,252
    Likes Received:
    1,906
    Trophy Points:
    331
    Well I've never seen sequential reads/writes on my eMMC better than ~90 MB/s, and my WD reds (consumer grade raid disks that cost ~10% more than typical consumer grade) I use in my servers get ~140-160 MB/s read/writes. Did you do any tweaks to get those speeds on your AVN8?

    As for the SSD on Bay Trail, I meant Atom Bay Trails. They don't support SATA or PCIe. The Celeron/Pentium SKUs do, but they don't support S0IX (active sleep states), so they don't get the good battery life that the Atom version does... So it was Intels choice =P

    Having said that, I think even if the OEMs had the choice they would go with eMMC because of the mindset Atom=Cheap. The CPU itself is plenty fast for my needs. If not for the eMMC I would have no problem with an Atom Bay Trail even on my "laptop". I'd personally be willing to pay a big price premium for SSD support, but maybe the market wouldn't on average...

    Regarding sequential vs IO as the bottleneck, I imagine your use case would be an exception. In fact, much of my work is an exception as well. I work with satellite imagery data and 3D global climate models. For that, sequential reads/writes are very often the bottleneck, but I don't do any of that on my tablet (except remotely via NX/RDP).

    I think for most users whom primarily work in MS Office and/or some other business tools, the sequential reads/writes are rarely the bottleneck, but that is just my guess of course. I can't say that I know for sure what the "average person" does on their machines =)
     
    Last edited: Mar 23, 2015
Loading...

Share This Page