The Samsung 860 QVO (1TB, 4TB) SSD Review: First Consumer SATA QLC
by Billy Tallis on November 27, 2018 11:20 AM ESTSequential Read Performance
Our first test of sequential read performance uses short bursts of 128MB, issued as 128kB operations with no queuing. The test averages performance across eight bursts for a total of 1GB of data transferred from a drive containing 16GB of data. Between each burst the drive is given enough idle time to keep the overall duty cycle at 20%.
The burst sequential read performance of the Samsung 860 QVO is generally competitive with mainstream TLC SATA SSDs and is well ahead of the DRAMless Toshiba TR200. The 1TB 860 QVO's score is a bit lower when the drive isn't full because of the timing of the tests: the drive was still flushing the SLC cache in the background when the read test started.
Our test of sustained sequential reads uses queue depths from 1 to 32, with the performance and power scores computed as the average of QD1, QD2 and QD4. Each queue depth is tested for up to one minute or 32GB transferred, from a drive containing 64GB of data. This test is run twice: once with the drive prepared by sequentially writing the test data, and again after the random write test has mixed things up, causing fragmentation inside the SSD that isn't visible to the OS. These two scores represent the two extremes of how the drive would perform under real-world usage, where wear leveling and modifications to some existing data will create some internal fragmentation that degrades performance, but usually not to the extent shown here.
On the longer sequential read test, the 860 QVO continues to get reasonably close to the SATA speed limit when reading data that is contiguous on the flash itself. Where internal fragmentation is caused by writing to the drive randomly, the QVO's read speed suffers much more than for the TLC drives, and the 1TB 860 QVO ends up slightly slower than a mechanical hard drive.
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| Power Efficiency in MB/s/W | Average Power in W | ||||||||
The power efficiency of the 860 QVO is only a little bit lower than the TLC drives for the contiguous data case. When dealing with fragmented data, the QVO is slightly more efficient than the Intel/Micron NVMe QLC drives despite being a bit slower.
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The queue depth scaling behavior for the 860 QVO is very typical, with QD1 not quite saturating the SATA link but all higher queue depths hitting close to full speed. The one exception is a slight decrease from the 1TB drive during the final QD32 phase.
Aside from the mild QD32 drop in performance, the sequential read behavior of the 860 QVO doesn't fall outside the normal ranges we've come to expect from TLC drives.
Sequential Write Performance
Our test of sequential write burst performance is structured identically to the sequential read burst performance test save for the direction of the data transfer. Each burst writes 128MB as 128kB operations issued at QD1, for a total of 1GB of data written to a drive containing 16GB of data.
The Samsung 860 QVO handles the burst sequential write test fine when the drive is mostly empty and there's plenty of room in the SLC cache. When the drive is full, the 1TB model's speed suffers somewhat, but is still much faster than the mechanical hard drive or the DRAMless TLC drive.
Our test of sustained sequential writes is structured identically to our sustained sequential read test, save for the direction of the data transfers. Queue depths range from 1 to 32 and each queue depth is tested for up to one minute or 32GB, followed by up to one minute of idle time for the drive to cool off and perform garbage collection. The test is confined to a 64GB span of the drive.
On the longer sequential write test, the SLC cache of the 1TB 860 QVO is not quite enough even when the drive is mostly empty, so it ends up in last place. The 4TB model's SLC cache keeps up with this test and it is as fast as any SATA drive.
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| Power Efficiency in MB/s/W | Average Power in W | ||||||||
The 860 QVO is a bit more power-hungry than the 860 EVO, so the 4TB QVO only takes third place for efficiency among the SATA drives in this bunch. The 1TB QVO has similar efficiency to the faster but more power-hungry 1TB QLC NVMe drives from Intel and Micron.
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The 1TB 860 QVO is mostly slow and steady during the sequential write test, while the 4TB model's performance is as good as any other SATA drive.
The 1TB 860 QVO's sequential write behavior sticks out clearly as far slower than typical, but it's not unprecedented: there have been TLC drives this slow, but most of them were much smaller than 1TB. The 4TB model blends in with the crowd much better.
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R0H1T - Wednesday, November 28, 2018 - link
>moozoohQVO is the first SATA QLC drive, so yeah first of it's kind unless we're being pedantic. As for the price ~ it should & will likely come down soon enough.
>Right now there is exactly zero reason to choose it over the EVO.
The 500GB EVO costs about $130 US where I'm from, there's very little incentive for me to buy it given the "inflated" price.
moozooh - Wednesday, November 28, 2018 - link
> "QVO is the first SATA QLC drive, so yeah first of it's kind unless we're being pedantic."The fact that it's the first or the only doesn't matter to anyone who's buying things based on anything resembling a performance/price ratio. It's the first to be inferior to an already existing product. Who would be the early adopter of something that's clearly worse than something else that costs more or less the same?
> the price ~ it should & will likely come down soon enough
So why didn't Samsung recommend a lower price to begin with, considering how badly this products needs it? I'm sure they follow the market close enough to see this series competes with their own EVO (and loses hands-down).
> The 500GB EVO costs about $130 US where I'm from, there's very little incentive for me to buy it given the "inflated" price.
Yet this makes the QVO more attractive for you, especially considering it doesn't even feature a 500 GB model? I don't understand your argument. The point is this drive needs to be much, much cheaper than the EVO to be attractive at all. The downsides of the QLC NAND are numerous and significant; they need to be offset using the price. It's also clear this is where the multi-bit madness should end, because QLC is already encroaching onto the HDD territory in certain aspects (except the price, sadly) and scenarios. If PLC were a thing, I'd most likely stay away from it even if it were cheaper than hard drives. That's just asking for trouble, like those glass platters in IBM's Deskstar 75GXP (one of the most disastrous HDD series of all time).
R0H1T - Wednesday, November 28, 2018 - link
>The fact that it's the first or the only doesn't matter to anyone who's buying things based on anything resembling a performance/price ratio.The fact is you quoted me when I said first of a kind, which holds true for this drive, end of!
>So why didn't Samsung recommend a lower price to begin with, considering how badly this products needs it?
I dunno, how about you ask Samsung why didn't they sell the 860 EVO for $130 at launch?
>Yet this makes the QVO more attractive for you, especially considering it doesn't even feature a 500 GB model?
Yes because the QVO model, when it launches here, should be cheaper ($/GB) than the EVO drives. It's not like I can't afford $130 drive, but the 1TB or 2TB would be better VFM for me, considering I'm looking to replace some HDDs permanently. The EVOs would probably still be 40~60% more expensive.
moozooh - Wednesday, November 28, 2018 - link
> The fact is you quoted me when I said first of a kind, which holds true for this drive, end of!Once again, the fact that I'm pointing out is that it is a non-argument. Early adopter premium only exists for something that such an early adopter would want to have NO MATTER THE COST. Such as a new feature or better performance with existing features. Here, the cost is the ONLY thing an early adopter would want about it and the only potential advantage, period. Why do you not see how you're not making sense? "One of a kind" is an idiotic argument to use for the product that's intended to be cheaper, not better.
> I dunno, how about you ask Samsung why didn't they sell the 860 EVO for $130 at launch?
They launched the 860 EVO at the same time with the 860 Pro with a significant enough difference in MSRP that one didn't cannibalize the other, and the EVO was also fast enough to overtake most of the competition widely available at that price point. So the pricing made sense at the time, not so much here.
> The EVOs would probably still be 40~60% more expensive.
Hopefully so, but Samsung's lack of aggression and insight in undercutting their own existing product is disappointing. They are well aware of the going price of the EVO.
R0H1T - Wednesday, November 28, 2018 - link
>moozoohWe're forgetting arguably the most important thing ~ yields. There were some (unconfirmed) reports that QLC yields were below par, so it's quite possible that these products being priced so close to TLC drives is a result of that.
moozooh - Wednesday, November 28, 2018 - link
I don't really think yields are important. It's not an attribute for customer to base their decisions on, it's not something that can be tested or seen, and needn't be either—it's the manufacturer's problem. After all, customers aren't altruists and aren't out there to help Samsung or any other vendor do their business—what they need to care about is that the products they buy are priced fairly. Samsung won't convince anyone to overpay for QLC because the yields are too low to justify a fair price.Two possible ways to handle this launch better would be either to bite the bullet and suggest a sensible MSRP from the get go or stabilize the technology before coming out with the product and selling it at a healthy margin. Either way there won't be many people buying this until it's sufficiently cheap so the difference isn't as big as it might feel.
FullmetalTitan - Thursday, November 29, 2018 - link
'Yields don't matter to initial consumer product pricing' is a pretty spicy take.It doesn't matter whether the consumers want to be altruistic (definitely not the correct usage here), this is the price if you want high density SSD storage in a single unit, like it or not. You clearly don't, so kindly shut up and move on.
Manch - Wednesday, November 28, 2018 - link
If the 500GB EVO is double the going price in your area, what makes you think the 860 QVO won't be?Me thinks, you've dug a hole. Stop digging LOL
R0H1T - Wednesday, November 28, 2018 - link
>double the going priceDouble the what? Do you know the price 860 EVO debuted in every country of the world, now can you guess the price QVO would retail for?
How about you stop assuming $130 US (1TB) is the normal EVO price everywhere around the world? Then stop reaching.
s.yu - Saturday, December 1, 2018 - link
If you're knowingly buying from an expensive source, you're buying it wrong. If you insist on buying it wrong, then stop wasting other people's time with your BS.Time to hit eBay, nowadays Taobao may help.