Random Read Performance

Our first test of random read performance uses very short bursts of operations issued one at a time with no queuing. The drives are given enough idle time between bursts to yield an overall duty cycle of 20%, so thermal throttling is impossible. Each burst consists of a total of 32MB of 4kB random reads, from a 16GB span of the disk. The total data read is 1GB.

Burst 4kB Random Read (Queue Depth 1)

The Toshiba RC100 surprises with excellent burst random read performance, and even when HMB is off it outperforms the other low-end NVMe SSDs we've tested.

Our sustained random read performance is similar to the random read test from our 2015 test suite: queue depths from 1 to 32 are tested, and the average performance and power efficiency across QD1, QD2 and QD4 are reported as the primary scores. Each queue depth is tested for one minute or 32GB of data transferred, whichever is shorter. After each queue depth is tested, the drive is given up to one minute to cool off so that the higher queue depths are unlikely to be affected by accumulated heat build-up. The individual read operations are again 4kB, and cover a 64GB span of the drive.

Sustained 4kB Random Read

On the longer random read test that covers a broader span of the drive than HMB can help with, the Toshiba RC100's scores are unsurprisingly in last place among NVMe drives, but it's not too far behind the Intel 600p.

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

The RC100 clearly uses less power during random reads than any other NVMe SSD we've tested, but the poor performance when reading from a wide span of the drive means the efficiency is just a bit below average.

For the larger RC100, the HMB feature has a fairly large impact on random read performance at high queue depths even though the HMB cache is too small to completely handle this workload. At low queue depths and for the smaller 240GB model at any queue depth, HMB has minimal impact on random read performance.

Random Write Performance

Our test of random write burst performance is structured similarly to the random read burst test, but each burst is only 4MB and the total test length is 128MB. The 4kB random write operations are distributed over a 16GB span of the drive, and the operations are issued one at a time with no queuing.

Burst 4kB Random Write (Queue Depth 1)

With HMB enabled, the burst random write performance of the Toshiba RC100 is decent, but without HMB it can't beat a mainstream SATA drive.

As with the sustained random read test, our sustained 4kB random write test runs for up to one minute or 32GB per queue depth, covering a 64GB span of the drive and giving the drive up to 1 minute of idle time between queue depths to allow for write caches to be flushed and for the drive to cool down.

Sustained 4kB Random Write

Once again, the large working set size of this test compared to the small host buffer size used by the RC100 condemns the drive to last place. The margin between the RC100 and the next-slowest NVMe drive is much larger than it was for the sustained random read test. HMB actually slightly hurts performance here.

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

Power consumption is slightly higher for random writes than for random reads, but still well below the other NVMe SSDs. The performance is low enough that the power efficiency score for the RC100 is worse than all the competition.

Random write performance from the RC100 is low at any queue depth. The drive doesn't have enough memory to perform effective write combining and caching under this sustained load, while high-end drives usually manage to significantly improve performance when working with a large queue of write operations.

AnandTech Storage Bench - Light Sequential Performance
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  • XabanakFanatik - Thursday, June 14, 2018 - link

    Seriously? We get this instead of the 970 Pro or 905p review? Did anyone actually care about this drive? Reply
  • Billy Tallis - Thursday, June 14, 2018 - link

    Personally, I find doing a review like this to be a lot more interesting than testing an overpriced flagship product where I know going into it that the conclusion will be that a drive 1/2 or 2/3 the price is just as good for realistic use cases. It's interesting to explore the current state of the art for high-end tech, but it's more interesting to explore new tech in the context of something that might also be a sane purchase. Reply
  • XabanakFanatik - Thursday, June 14, 2018 - link

    I'm not sure how interest explains why you've reviewed this two days after it shipped but 7 weeks after you posted the 970 Evo review, there is no 970 pro review. Every other inferior review website posted the pro and evo reviews simultaneously, so Samsung must have sent you both drives around the same time.

    And Seriously, this is more interesting than reviewing the first optane refresh 905p?
    Reply
  • close - Thursday, June 14, 2018 - link

    They're usually very late with most reviews. Except Intel ones.

    Ostensibly because they want to provide the best information out there.
    Reply
  • Samus - Thursday, June 14, 2018 - link

    Need a review of a 970 Pro? Read the 970 Evo review and assume it’s moar better for proportionately moar money. Reply
  • bananaforscale - Monday, July 09, 2018 - link

    Not proportionately. Flagship products *never* have a price that's proportional to performance. Reply
  • artifex - Thursday, June 14, 2018 - link

    You already know a bazillion other sources for a 970 Evo review, so you're beating this guy up for being different? He says doing this review is more interesting for him, so no wonder he did it.

    Also, since you're calling Anandtech an inferior review site, he's hardly likely to change just for you, now.
    Reply
  • XabanakFanatik - Thursday, June 14, 2018 - link

    I was saying every other review site was inferior, yet they posted 970 PRO reviews the same time as 970 EVO reviews. My issue with Anandtech was the sole posting of the 970 EVO review and no 970 PRO review now for over 7 weeks.

    Nobody tests like Anandtech. I'm sad that the halo drives aren't a priority for Billy, since the market for them is actually really big.
    Reply
  • lmcd - Thursday, June 14, 2018 - link

    Most people I know look at the 970 EVO as the highest price drive they'll consider. I almost didn't even consider it. Reply
  • XabanakFanatik - Thursday, June 14, 2018 - link

    I can think of a half dozen people I know that would have never considered the 900 Pro drive at the previous price point that bought one after Samsung's mysterious price drop at launch of the 970 series. Lopping off 20-25% of MSRP tends to work pretty well to sell a new generation that was previously priced too high. Reply

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