# Do QLC NVME drives retain read speed when loaded?



## thevisi0nary (Jun 4, 2021)

I know QLC drives have issues with write performance when near capacity compared to tlc drives, but does the same apply to just reading? Will a QLC drive used only for sample libraries / samples perform more similarly to TLC drives if you aren’t ever writing to them? I have only ever had TLC drives so I can’t try this myself.


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## Pictus (Jun 6, 2021)

I do not have any experience with QLC, but I see no reason
why they will not stay fast for reading data.
Check the reviews for the model you plan to buy and you will know.
Pay attention to Q1 random/sequential read or game load tests.


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## Toecutter (Jun 6, 2021)

For samples, SLC > MLC, TLC, QLC?

I know SLC is supposed to be more expensive but are there any real advantages for us?


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## Technostica (Jun 6, 2021)

Average read latency does vary depending on how full a drive is.
Not sure how significant this is in terms of real world performance though.
Here's a review and you can select which metrics to look at.
The QLC drive (MP600 Core) is one of the more impacted ones but that's just one drive.









The ADATA GAMMIX S50 Lite 2TB SSD Review: Mainstream PCIe Gen4







www.anandtech.com


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## Pictus (Jun 6, 2021)

For samples the bottleneck is the software, the same goes for video game level loading...









Corsair MP400 2 TB Review


The Corsair MP400 is one of the fastest QLC-based SSDs we've reviewed so far. With its 2 TB capacity, it offers plenty of space for all your apps and games, and achieves real-life performance that's comparable to many TLC-based SSDs.




www.techpowerup.com














Corsair MP600 CORE 2TB M.2 SSD Review


Corsair is taking Gen4-powered QLC to new heights with its MP600 Core Series. Here's our look at Corsair's 4-Bit Gen4 powerhouse.




www.tweaktown.com


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## colony nofi (Jun 6, 2021)

We have a bunch of QVO drives - some as full as 85%. No performance differences to the day we started to load stuff onto them. (within 10%)


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## newbreednet (Jun 7, 2021)

thevisi0nary said:


> I know QLC drives have issues with write performance when near capacity compared to tlc drives, but does the same apply to just reading?


I remember reading something by the always-insightful EvilDragon in another thread about this; he said, "fill 'em to the brim!"

I took this advice to heart


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## EvilDragon (Jun 7, 2021)

Yep. Fill 'em to the brim. 

What matters most for direct-from-disk streaming is the 4K random read speed. And, considering Kontakt is not SSD-optimized, look at QD1 figure (queue depth of 1, which is about the slowest SSDs do, when there are higher queue depths this is where you get a real speed boost from the SSD tech).


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## Toecutter (Jun 7, 2021)

EvilDragon said:


> considering Kontakt is not SSD-optimized


Is this a priority for the dev team or does it even matter? Seems that the CPU is the bottleneck anyway... Or maybe there are other benefits of being "SSD-optimized"?


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## EvilDragon (Jun 7, 2021)

CPU is gonna be the bottleneck definitely for quite some time. 4K random read QD1 on an average SATA SSD (so, not even NVMe) can be between 30-50 MB/s (megabytes, not megabits).

Consider your DFD buffer size. For SSD you can set it super low, but let's say for the purpose of the example that it's set to 12 KB. This means, in case of say 30 MB/s, you could stream roughly 2500 mono voices (or 1250 stereo) effortlessly before SSD starts saturating a bit - if my math is correct. 

In short, it's not a priority (plus, DFD code is one of the most sensitive parts of Kontakt, who would want to mess it up?)


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## thevisi0nary (Jun 7, 2021)

Thank you all


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## storyteller (Jun 8, 2021)

EvilDragon said:


> CPU is gonna be the bottleneck definitely for quite some time. 4K random read QD1 on an average SATA SSD (so, not even NVMe) can be between 30-50 MB/s (megabytes, not megabits).
> 
> Consider your DFD buffer size. For SSD you can set it super low, but let's say for the purpose of the example that it's set to 12 KB. This means, in case of say 30 MB/s, you could stream roughly 2500 mono voices (or 1250 stereo) effortlessly before SSD starts saturating a bit - if my math is correct.
> 
> In short, it's not a priority (plus, DFD code is one of the most sensitive parts of Kontakt, who would want to mess it up?)


Your math is correct. I was also benchmarking an i9 iMac‘s internal SSD today vs a Samsung 860 SATA SSD in a TB3 enclosure in Kontakt. Long story short, whether it was the internal NVME (2800MB/s) or the SATA (540MB/s), they both achieved practically the same results BEFORE crackles and pops started showing up. This was right at the saturation point of the SATA... but surprisingly the NVMe internal didn’t yield any better performance.


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