Samsung EVO vs QVO SSDs Compared – Which one’s better?

CG Director Author Alex Glawionby Alex Glawion   /  Updated   /   7 comments
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Samsung EVO vs QVO SSDs Compared – Which one’s better?

Samsung—possibly the most prolific SSD brand on the market—recently released a new line of SSDs to go with their other popular options, the Samsung 870 QVO.

Let’s see how it stacks up with Samsung’s other offerings.

Although SSDs are great, there has always been a slight problem with them, one which prevented them from getting mass appeal as both primary and secondary mass storage.

Cost.

SSDs are blazingly fast, but their cost-per-gigabyte ratio compared to a traditional HDD has always been terrible.

But Samsung’s new QVO SSDs just might be what’s needed to change that paradigm—if they can compete with the already relatively affordable EVO drives, that is.

Introducing QVO

Samsung QVO SSD

Image Credit: Samsung

Released on June 30th, 2020, Samsung’s new QVO line of SSDs brought high capacity storage and speeds comparable to far higher-end SSDs, all while being close to half the price of a similar-sized Samsung PRO SSD.

SSD Drive Size

Image Credit: Samsung

And when I say high capacity, I mean high capacity. Samsung offered sizes exceeding 1TB all the way up to 8TB—something that few other SSDs in the general consumer market offered at the time.

SSD sizes greater than 2TB or even 1TB have always mostly been reserved for enterprise uses or power users who want to be on the cutting edge of the market

These drives could cost upwards of $200 or more and break a thousand dollars easily.

They just weren’t a wise investment for your average Joe or Jill who didn’t need the absolute best of the best when the most storage speed intensive task that they needed to be done was general photo/video editing.

Not when they can just as easily get an HDD that was comparable size-wise and had workable speeds for a tiny fraction of the cost.

But what about with QVO?

You could get a 1TB QVO model for about $90, easily. While the EVO and PRO variants hover around $110 and $200 respectively, which makes the Samsung QVO a far more affordable and reasonable option.

 Samsung 870 EVOSamsung 870 QVO
Capacity250GB / 500GB / 1TB / 2TB / 4TB1TB / 2TB / 4TB / 8TB
ControllerSamsung MKXSamsung MKX
NAND Flash Memory3bit MLC V-NAND [TLC]4bit MLC V-NAND [QLC]
DRAM Cache Memory512MB / 512MB / 1GB / 2GB / 4GB1GB / 2GB / 4GB / 8GB
Form Factor2.5 inch2.5 inch
Sequential Read, Write560 MB/s, 530 MB/s560 MB/s, 530 MB/s
4KB Ran. Read (QD32)98,000 IOPS98,000 IOPS
Total Byte Written150TB / 300TB / 600TB / 1,2PT / 2,4PT360TB / 720TB / 1,44PT / 2,88PT
MTBF1.5 million hours1.5 million hours
Warranty5 years limited3 years limited
Cost per Gigabyte$110/TB$90/TB

Samsung QVO & Longevity

If these drives are so great, why isn’t everybody switching to them?

Well, there’s a bit more to it than that.

Like with most things, all those sweet features have a cost.

And that cost is speed and longevity. But mostly just longevity.

See, before I can explain what that is, I need to explain a bit about how SSDs work. Don’t worry, it’s not too technical.

As opposed to using platters to store data like HDDs, SSDs work by using something called NAND Flash to physically store data on the SSD.

NAND Flash does this by using electrons that represent 1s and 0s or charged or not charged states.

As you might know, anything digital is ultimately made up of billions upon billions of 1s and 0s which when taken together makes up the very article you’re reading and everything else that you see on your monitor right now.

These electrons move and jump between 1 and 0 an incomprehensible amount of times whenever you’re changing the memory that is stored within them in any way.

This is called a “P/E cycle” or Program/Erase cycle.

This is a process that slowly breaks down and degrades the hardware of the SSD.

Now, this isn’t a super-fast process. Usually, you’ll have to read and write things to the SSD hundreds of thousands of times constantly for a typical modern SSD to degrade to a point where it starts losing data.

And there’s a vast difference between how many P/E cycles the different NAND Flash types can take.

The different types are:

  • SLC (Single-Level Cell)
  • MLC (Multi-Level Cell)
  • TLC (Triple-Level Cell)
  • QLC (Quad-Level Cells)
  • And the upcoming PLC (Penta-Level Cells)—if some rumors are to be believed.
Storage Density in SSDs

Image Credit: Data&StorageAsean

SLC stores one bit of data in two states—1 and 0. MLC stores two bits of data in four states, TLC stores three bits in eight states, and so on and so forth.

The problem with this increase is that each consecutive version isn’t as fast as the previous one and is more unstable.

The reason why I said that speed isn’t as much of a factor compared to longevity is that because of better controller algorithms and better binning of the actual flash, speed has stayed relatively competitive with other higher-end offerings.

Of course, it’s not as fast as the highest-end offerings, but since it’s so much cheaper, that’s a pretty good compromise.

But longevity is a different matter.

So, it won’t last?

Well, it’s a bit more complicated than that, but TL;DR, I suppose, would be that.

The exact numbers vary from SSD to SSD and there’s no way to truly say how long a given SSD will last, but we can make an educated guess based on its quality and specifications.

Average SSD Lifespan

Generally, SLC lasts for up to about 100,000 P/E cycles (one cycle is writing or erasing one block). MLC up to about 3000, TLC between 500 and 2000, and QLC between about 300 and 1000.

As you can see, SLC is significantly better, but it generally doesn’t come in large capacities and it’s significantly more expensive compared to all the other options.

They’re generally reserved for large enterprise setups where speed and stability are the biggest concerns and money is less of an obstacle.

You can get them as well, but be ready to dole out a pretty penny.

Samsung QVO uses QLC

You now understand what that signifies in this context.

Okay, don’t panic. Just ’cause its older cousins are better than it, doesn’t mean that QLC doesn’t have its rightful place. And just ’cause its older cousins can potentially last longer than it, doesn’t mean that it’ll die instantly.

You’ll still have to fill it up millions of times to even get close to degrading it. If you wrote 100GBs to the drive every day, it’ll still take you about 10 years to see any degradation.

SSD performance comparison

QVO is great as low cost, relatively fast, bulk storage, but if you plan on constantly streaming data to it from, say, an 8k, 60fps camera, or perhaps as a surveillance or busy server database SSD, you’ll quickly run into issues.

That’s because QLC is very, very slow. Slower than some mechanical HDDs even.

But, there’s a way to make it work better—otherwise, manufactures would never have made these slower drives in the first place, so Samsung’s more modern take on it is something called Intelligent TurboWrite.

Intelligent TurboWrite

Intelligent TurboWrite is a technology developed by Samsung that allows an SSD to “simulate” the faster SLC NAND on a part of the drive for quick bursts of speed before slowly unloading that data into the slower MLC, TLC, or QLC NAND.

intelligent turbowhite performance

This, along with part of the NAND actually being SLC, allows a Samsung SSD to work at far higher speeds, but only for a certain amount of data—between 42GB and 72GB depending on what capacity you go with and depending on whether the drive is close to being full or not.

Because if it’s close to being filled up, it’ll use that fast storage up for files, leaving none for what it’s there to do, caching.

QVO Transfer Speeds

Let’s get into some of the numbers.

NAND Flash PE Cycles vs Bits Per Cell

Say you’re sending a single 30GB file from another SSD to a 1TB Samsung QVO SSD—assuming that the source is fast enough to keep up, of course, what the QVO SSD will do with this data is that it’ll store it in its QLC memory and its SLC memory simultaneously, in a way that’ll have the SLC memory acting as a buffer for the QLC memory.

Meaning anything you send to the drive will at first be put into the SLC cache extremely quickly before being sent off to the QLC memory.

Samsung QVO drives’ write performance without Intelligent TurboWrite is around 80MB/s.

Its write performance with Intelligent TurboWrite is around 560 MB/s.

That 30GB file transfer operation would take about 53~ seconds to complete on a QVO drive.

Pretty snappy, right?

And then say you wanted to transfer another 30GB file right away.

What will happen then?

After transferring 12GB of the file at that same speed, your transfer will slow down to a crawl and run at atrocious speeds of around 80MB/s because it has now filled up the 42GB buffer and is transferring directly to the far, far slower QLC memory.

That’s about four minutes for the second 30GB transfer!

Any transfers that you manage to complete after this point will also be running at that extremely slow speed until the SLC cache has finished dumping the data that it’s holding into the much slower QLC memory.

After which you’ll get those blazing fast speeds again.

EVO Transfer Speeds

We need something to compare all that to. So let’s see how a 1TB Samsung EVO drive might handle that task.

Samsung EVO drives’ write performance without Intelligent TurboWrite is around 300MB/s.

Its write performance with Intelligent TurboWrite is around 530 MB/s.

That 30GB transfer operation would take a whopping 56~ seconds to complete.

Eh? What’s up with that?

The more expensive EVO is actually slower?

Not really, actually. I would say that it’s well within the margin of error. The EVO really shines during the second operation, or if your transfers are bigger than the QVO buffer.

What do you think would happen here?

After transferring 12GB of the file at that same speed, your transfer will slow down and run at speeds of around 300MB/s. Completing it in almost exactly a minute.

Four times as fast as QVO!

EVO vs QVO

So what’s the point, right? EVO all the way! Well, hold that thought…

bestfit workloads for different NAND flash

Here’s the thing. That example highlights only one example of a potential workload. It’s almost unfair to QVO to have picked something like that to showcase, but that’s the point.

That test shows what the QVO wasn’t made to do. It exposes QVO’s weak points. Which is writing extremely large files (Extremely high-quality video capture for example) to the drive—reading on the other is generally unaffected or very mildly affected.

EVO wasn’t exactly made for that either, but because of its MLC memory, it is significantly faster than QVO even without Intelligent TurboWrite.

But what if you don’t want to do that? What if you just need a drive for general purpose work? Or perhaps gaming?

Would QVO work for the average layman?

Yes! It would work quite wonderfully, actually. For the most part, you won’t noticeably feel a difference between a QVO and, say, a PRO.

These applications just don’t require that much speed, so it becomes quite redundant after a certain point, and they don’t hammer the SSD as a single large file could do.

The average person’s general applications will usually work on a QVO drive perfectly fine.

In Conclusion/TL;DR

Samsung EVO performs much better than QVO, but the value isn’t necessarily higher in every single application.

If you want to work with extremely large, high-quality files, and you need to transfer them at high speeds without any slowdown, you should definitely get an EVO or a PRO.

If you need to do anything else such as general computer usage, gaming, or other workloads that don’t demand high storage performance, you’ll be perfectly fine getting a QVO SSD and saving a few bucks.

 Samsung 870 EVOSamsung 870 QVO
Capacity250GB / 500GB / 1TB / 2TB / 4TB1TB / 2TB / 4TB / 8TB
ControllerSamsung MKXSamsung MKX
NAND Flash Memory3bit MLC V-NAND [TLC]4bit MLC V-NAND [QLC]
DRAM Cache Memory512MB / 512MB / 1GB / 2GB / 4GB1GB / 2GB / 4GB / 8GB
Form Factor2.5 inch2.5 inch
Sequential Read, Write560 MB/s, 530 MB/s560 MB/s, 530 MB/s
4KB Ran. Read (QD32)98,000 IOPS98,000 IOPS
Total Byte Written150TB / 300TB / 600TB / 1,2PT / 2,4PT360TB / 720TB / 1,44PT / 2,88PT
MTBF1.5 million hours1.5 million hours
Warranty5 years limited3 years limited
Cost per Gigabyte$110/TB$90/TB

FAQ

What does QVO mean?

From what I can find, Quality and Value Optimized.

What does EVO mean?

No clue. But it might mean Evolution and Value Optimized.

It doesn’t make much sense, but considering that the word “evolution” is all over the box for an EVO, that seems like a safe bet.

Does Samsung QVO have DRAM?

It does. It has LPDDR4 ram. Starting at 1GB, it doubles as the storage space increases starting from 1TB (2TB – 2GB | 4TB – 4GB | 8TB – 8GB).

What is 3D NAND?

Simply put, it’s stacking NAND chips on top of each other. It allows for far denser storage solutions.

What is the TBW of an SSD?

Terabytes Written or “TBW” it’s another metric that you can use to determine SSD endurance. It’s used to signify how much data, in general, you can expect to write to the SSD throughout its lifespan. (300TBW = 300TBs)

Should I buy an external SSD or HDD?

If you’re someone that’s on the go always, that sounds like a wise investment. External SSDs are generally a bit slower than internal ones, however.

But if you plan on using it on one system, you have the appropriate connectors and cables available, and you don’t need the portability, go for a traditional SSD.

How long will an SSD last?

That’s hard to say. But generally, it’s assumed to be around 10 years.

What do I need to check before buying an SSD?

If you’re buying a SATA SSD, there’s not a whole lot to check.

Pretty much any computer made in the last 15 odd years has some sort of SATA connectivity that will work.

If you’re planning on getting an NVME SSD, make sure to check beforehand if your motherboard can actually take in an NVME SSD, and if so, what type and length NVME drive it can take.

 

That’s about it from us! Let us know of any questions in the Comments or the Forum!

Alex Glawion - post author

Hi, I’m Alex, a Freelance 3D Generalist, Motion Designer and Compositor.

I’ve built a multitude of Computers, Workstations and Renderfarms and love to optimize them as much as possible.

Feel free to comment and ask for suggestions on your PC-Build or 3D-related Problem, I’ll do my best to help out!

7
Comments
Also check out our Forum for feedback from our Expert Community.

Wade

Wow, you are one smart cookie. Thank you for the layman summary at the end

Chris

Great article and exactly what I was looking for.
I am a 3d artist working mainly on zbrush and I want a new SSD to use as my drive that I store the zbrush files that usually are from 100mb up to 1-2gb and in some rare occasions 5 or more gb per file.

Do you advise me to get and Evo or a qvo for storing zbrush files and working on zbrush while the files are stored on the SSD.
Thanks in advance!

Chris

Alex Glawion
Alex GlawionCGDIRECTOR

Hey Chris,
If it’s mostly for storing only, and you don’t do a lot of continuous transferring, the QVO will be more than enough for your use-case.

Cheers,
Alex

Chris

Thanks for your reply Alex! Really appreciate it 🙂

Shaked Akrish

Thanks for the great information! I want to know if Samsung QVO will be enough for 4k Braw video editing. According to what you wrote it should work well but I want to make sure before making any purchase.

Alex Glawion
Alex GlawionCGDIRECTOR

Hey Shaked,
The QVO should be fast enough for 4K raw editing but it’ll also depend on the footage format and codec. If the footage needs performance hungry decoding, the CPU will be more of a bottleneck than the storage. If your codecs are easily decoded and your raw files are very very big (e.g. 12bit or higher RED) the storage might become a bottleneck.

Cheers,
Alex

Shaked Akrish

Thank you Alex!
The files are Blackmagic RAW 8:1 compression. I eventually went for the Samsung 870 EVO version so I hope it will work fine.