Mixed Random Performance

Our test of mixed random reads and writes covers mixes varying from pure reads to pure writes at 10% increments. Each mix is tested for up to 1 minute or 32GB of data transferred. The test is conducted with a queue depth of 4, and is limited to a 64GB span of the drive. In between each mix, the drive is given idle time of up to one minute so that the overall duty cycle is 50%.

Mixed 4kB Random Read/Write

This mixed random IO test covers a fairly wide span of the drive, so it's not a surprise to see that the Toshiba/Kioxia BG4 and other DRAMless SSDs end up being among the slowest drives overall, with HMB providing little or no help.

Sustained 4kB Mixed Random Read/Write (Power Efficiency)
Power Efficiency in MB/s/W Average Power in W

The power consumption of the BG4 during this test is as low as any other drive, but the limited performance means its efficiency score is still clearly worse than most of the drives that have their own DRAM.

The performance of the BG4 is low and relatively flat across this test, declining slightly as the workload gets more write-heavy when most drives gain performance. With a working set small enough for the BG4's HMB configuration to be useful, we would likely see a very different performance profile.

Mixed Sequential Performance

Our test of mixed sequential reads and writes differs from the mixed random I/O test by performing 128kB sequential accesses rather than 4kB accesses at random locations, and the sequential test is conducted at queue depth 1. The range of mixes tested is the same, and the timing and limits on data transfers are also the same as above.

Mixed 128kB Sequential Read/Write

The BG4 is a bit more competitive on the mixed sequential IO test, almost matching the XG6's overall performance and more or less tied for fastest among the entry-level NVMe drives.

Sustained 128kB Mixed Sequential Read/Write (Power Efficiency)
Power Efficiency in MB/s/W Average Power in W

The BG4 comes out on top of the power efficiency rankings, with the WD Black SN750 a close second. Even with the lower performance of running without HMB, the BG4 stays near the top of the efficiency chart.

Without HMB, the BG4's performance across the mixed sequential IO test is mostly flat, with a bit of an overall decline as the workload becomes more write-heavy. Enabling HMB allows the BG4 to pick up some speed during the last third of the test, but it doesn't have a huge impact.

Sequential Performance Power Management
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  • MrCommunistGen - Friday, October 18, 2019 - link

    I recently picked up a Dell Optiplex 3070 Micro for a family member, and it shipped with a 128GB BG4. Performance of the 128GB model is going to obviously be much lower than the 1TB model tested here.

    From my anecdotal experience, performance is acceptable, but could easily be better. I replaced it with a 1TB XG6 (~$120 from eBay) - mostly for capacity, but the performance uplift was (understandably) noticeable.
  • abufrejoval - Friday, October 18, 2019 - link

    Nice review for a solid product: Thanks!

    While I guess it reduces the worries about a soldered down SSD somewhat, I just hope they'll continue to sell even ultrabooks with M.2 or XFMExpress: Just feels safer and helps reducing iSurcharges on capacity.
  • Targon - Friday, October 18, 2019 - link

    Agreed. If the motherboard fails, being able to remove the SSD for data recovery SHOULD be seen as essential by most people.
  • Wheaties88 - Friday, October 18, 2019 - link

    I don’t see why most manufacturers wouldn’t see it as useful as well. Surely it would allow for less replacement motherboards needed if they could simply change the drive size. But what do I know.
  • kingpotnoodle - Monday, October 21, 2019 - link

    Nobody considers it essential because relying on removing your SSD for data recovery if the motherboard fails is a deeply flawed strategy and not applicable to the vast majority of people who wouldn't even consider opening their laptop nevermind knowing how to remove the drive and access it outside the laptop.

    The same thing that saves you if your SSD fails will also save you if anything else makes the machine unbootable - a proper backup.
  • Targon - Monday, October 21, 2019 - link

    You haven't had people come to you because their laptop has died but they need their data? Consumers may not be ready or able to get data from a dead laptop that has a drive you can remove, but the places they turn to SHOULD be able to.

    Tell me, can you recover data from a dead Macbook(dead motherboard) these days with the storage on the motherboard yourself? If the motherboard in your own personal laptop failed, wouldn't YOU want to be able to pull the drive if you needed data from it?
  • abufrejoval - Friday, October 25, 2019 - link

    Those who know me well enough to entrust me with their computer, know me well enough not to come close with a Macbook.

    And I am not even all *that* prejudiced. I loved my Apple ][ (clone), went for the PC because even my 80286 already ran Unix and I was a computer scientist after all.

    I keep doing Hackintoshs every now and then, just to get an understanding of how a Mac feels and because it's a bit of a challenge.

    But it's seriously behind in just about every aspect important to me: The combination of Linux and Windows gives me much more in any direction, for work and for fun. And mixing both is much less of a technical issue than life-balance.

    And then the notion of having your most personal handheld computer managed by an external party is just so wrong, I am flabbergasted that Apple managers still walk free, when computer sabotage is a felony.

    The Apple ][ didn't even screw down the top lid. Swapping out components and parts, adding all sorts of functionality and upgrades made it great.

    This solid brick of aluminum, glue, soldered on chips and hapless keyboard mechanics they call an Apple computer these days is just so wrong, I'd throw it into recycling the minute I got one for free. I don't know if I could give an Apple notebook or phone even to a foe, let alone a friend.
  • domboy - Friday, October 18, 2019 - link

    Since Microsoft used this in the Surface Laptop 3, I wonder if they also used it in the Surface Pro X since that also has a removable SSD. I'll be interested to find out...
  • taz-nz - Friday, October 18, 2019 - link

    Now we just need them to apply this tech to a standard 2280 form factor and give us a 4TB m.2 SSD, doesn't have to have best in class performance just a consumer class 4TB m.2 SSD.
  • Death666Angel - Saturday, October 19, 2019 - link

    There already are Samsung and Toshiba 4TB M,2 drives.

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