QLC vs TLC SSDs: Samsung QVO & EVO 

You explain everything so clearly. Keep up the great work!

I really wish they change MLC to DLC (Dual Level cell ) , but that may result a copyright infringement lawsuit from EA 🤔🤔.

I think this "42GB cache" deserves some explaination: Both drives may truly have 42GB cache, but while writing such large sequential files, drives use their much higher IOPS capability to write to TLC/QLC and the SLC cache at the same time... We know QVO's QLC (as seen around 12:26 mark) is barely capable of ~75MB/s without using cache so here is the math: From the start of the video up until it slows down at 1.35 QVO drive had written 75 - 29= ~46GBs... Of which, drive write at its known ~75MB/s speed to as QLC (from the start) for first 95 seconds, approximately storing 4,4GBs worth of data.. Remaning data is 46 - 4,4 = 41,6GBs which couldn't be written to slow QLC, so it has to be written to 42GB SLC cache, filling it and then slowing down transfer to only what QLC is capable of... Since evo does exactly the same and writes to TLC and SLC at the same time, but TLC itself is much faster than QLC (roughly around 200-250MB/s), your 75GB test file probably wasn't enough to fill up its 42GB SLC cache... This is the exact behaviour I've observed from my tests with my own intel 660p... It doesn't "simply" fill up its 76GB cache (when 50% full) and then slow down... If I hammer it with burst 1.5GB/s writes it does just that (technically it probably doesn't but it doesn't make a noticable difference)... But when writing from a slower source at ~340MB/s, drive doesn't slow down even at 120GB file transfers... This dynamic cache behaviour matters a lot more than it would seem in real life use cases.. When transferring large a game for example, it has both large files and small ones.. My reading source is two SATA SSDs in RAID-0 configuration... If the source sends burst of sequential files @1GB/s, 660p caches them.. When source slows down ~60 MB/s to read hundeds of

what a joy to hear a PERSON explain these things instead of a computer voice bombarding us with useless abbreviations without any explanation whatsoever. Great job, thanks.

QLC needs some TLC to feel better.

i wish all of my teachers were like this guy, i would've actually learned something.

I came originally planning to skip to the last 5 mins to see which was better, but got my attention and ended up watching the whole thing, actually made it super interesting!

This channels has legendary quality content. It is extremely concise and well produced.

What a lucid explanation. Clearly stated, no waffle - exactly what I was looking for!

Thanks for the many videos you make and all the information you pass on .

most thorough exposure of the drawbacks of these QLC drives that i have seen, great video

Wow, thats incredibly informative. I really enjoyed that. Hoping for more of this type of content from you, CB

Samsung engineer: we made a drive that stores data on it Samsung marketing: we made a drive that makes a difference lol

Your video contains lot of technical information. Keep posting this kind of videos. Really appreciate your work. Thank you.

This is vital information for me and I appreciate that you do the research and share it all so clearly and concisely. Explaining Computers is my most favorite RU-vid channel bar none. Please keep up the great work. And Thank You! :-)

Excellent, very descriptive, very well documented and presented comparison and explanation of TLC and QLC technology of SSD drives. Thank you so much for that. Once again, your video is worth more than reading quite a number of different benchmarks. It is so rare to come across such top-notch information presented in impeccable English. I am 63 years old, I have used computers and done extensive programming since 1979 and, yes, I wish I had teachers like you when I was still a student. Thank you so much!

As always, short and concise. Thanks for explaining!

Again - one of the clearest and yet detailed explanation of "tricky" SSD technology - Not all companies are transparent on their SSD designs either - Thanks for clearing this up!

This was the perfect level of complexity about SSDs for me. Very well explained, thank you

Thanks, this was a very well made and thought out video with a very interesting topic that has caught my interest. Thank you so much for all your hard work and the effort that you put into these videos that have both an educational value and entertainment one for the mind.

Brilliant! I was looking at Samsung SSDs this morning and wondered what this meant! Perfect timing.

Fascinating, you keep me up to date with new technology. Thanks from an old computer engineer.

Awesome video... In 17 minutes, all you every wanted to know about SSDs and the difference between EVO and QVO... hundredths of pages and several sellers never actually made it that clear for me. Thanks. Subscribed !

I love the fact that this channel keep its classic appeal and I'm very much appreciate the clear explanation.

I absolutely love this channel!!! I have been into computers both personally and professionally for many many years and I learn so much from you, thank you so much!

So you're saying SSD's work off of some form of wizardry.

Thank you! Congrats on nearly reaching 1mill subscribers!

Another impressive well defined video. You sir, are invaluable to RU-vid and to all of your subscribers.

As you know from my previous posts, I have flash memory data expertise in building and designing hardware dating back to 2008 and even further if you consider spinning drives as well as being a contributor for m.2 and other newer open source standards. So I pay particularly close attention to these subjects more than others. That being said, I felt like your presentation was excellent! I have started using your clips occasionally in presentations. So hopefully you get even more followers as a result.

Like always a very well done presentation with all the relevant info!

I just installed two 500 GB 860 EVO's. I needed to replace an aging WD 500 GB Blue HHD that is around eight years old. After installation and migrating my PC's windows OS and various other programs, from the HHD to the SSD, I have to say I am very impressed by the performance. From boot up to running DOOM 2016, on ultra settings 1440P 60FPS, it is a huge game changer. Although, I was a bit skeptical at first, my brother had already made the leap a few months before. I am glad he helped in changing my mind. Cheers to you K.

Another excellent video Chris , I was a skeptic and very scared of life expectancy and now love my Samsung EVO 860 ! Thanks for this fine video and your excellent and unique style it’s simply the best !

Awesome Video Chris, Thank you for sharing your knowledge.

I like all the single board computer demonstrations on this channel, very interesting stuff. However, I found this channel doing research on SSD's. So I love the videos, like this one, that go over all the technologies involved along with tests. Excellent video 👍

Wow! I love this guy! Not only is he great at what he does, but he's a great character too! Very engaging! The videos have excellent production values! Always well worth a watch! Well done! 👍

Really great explanation, thanks for all the technical info! I think many people will find this helpful, as I certainly did.

Great information presented clearly as always. Thanks again!

I am still working with a EVO 840 250Gb for 4 years now and i still have no complains about the drive. I am at 1/2 way of its lifetime now. I used 60Tb while its lifetime expects to have in between 120 to 150Tb writing. But my next drive soon will be an EVO 860 1 Tb drive for certain.

Absolutely fantastically presented and superbly informative. Once again you have taught us well Obi Juan. Thanks for all your research.

I really do love your channel. Got me into tinkering on computers. Keep up the good work man.

Very informative and easy to grasp, thank you. Please keep it up.

Hello Sir Your channel is the best channel on RU-vid. No ad no background music. Only the good subject. I appreciate it. Keep it up.

Always great videos that teach me something valuable. This one was excellent!

Fantastic info! This video is by far the best at differentiating between the two drive technologies. Thank you 😊

Thanks so much, it was very informative and something I need to take note of.

Extraordinary well explained! Thank you sir - subscribed and liked!

Great explanation sir !!! I was looking for this technology to understand the basics.. Thank you for this video.

Everything clearly explained and simplified as I struggle to understand technical terms and or phases. Awesome channel.

YESSSS! I made the right decision! Thx for this video, I just bought 2 of these 1TB, and I was wondering if QVO or EVO would be the better choice. I went for EVO and now see I did the right thing because I too have large video files to shovel around. And the result of the comparison made my day. Thx Chris, good video as always.

Another very well explained video. Thanks.

Yet another outstanding sharing of timely information. You rock Chris!!!!!!!!!!!

Thanks for a very clear explanation of the differences between these two types of drive.

Hello Chris👋🏻 Every Sunday your videos remind me of the simple fact that I get for granted: my passion for learning&explore that triggers all possible switches of my natural curiosity that got me anyway deep in dealing with IT and computers in all correlations imaginable. And beyond IT. Thank you for your valuable work and efforts. 🏆🥇

As someone who watches many videos in the tech side of RU-vid; I have to say this is probably one of the best I've ever watched. Not only is the theory there but also most aspects of practical information I could ever wish to find in a single video. Amongst other useful information there are comparisons between two current market leading SSDs, which is of high value to those buying SSDs right now, and also including current market price to give the viewer a better idea of price to performance, which is a significant concern for the average buyer.

This is the best explained video of QLC drives I've found. I've tried to explain to people the differences but they often just don't understand. I will be sharing this video for sure.

I love that I understand when you explain computers Chris

Thank you. I appreciate you explaining these things.

Great video, informative indeed, I wish we had bank holiday Monday specials.

wow, so informative and so clear that I didn't skip a second in fact I had to listen again to some parts of this beautiful lesson. Thank you so much Sir.

Great video. I did not know that SSD’s came in different “flavors”. I saw the cost differences, but did not understand why. Now I do! THANKS!

G'day mate. This past 6 months has been a technological-hunt for extra resourceful and primary computing knowledge of current OS/programming/IoT, programming, hardware and software development. It's been a radical process - I've learnt so much more than expected and it has become a major endeavour and hobby. Yet another great opportunity to sponge up critical information and positively great channel!! thanks for helping hand Chris :) Ps. can you please possibly discuss/review the Onion Omega2+? Not many great results or resources for this topic and I am very interested in your comments!! Keep smashing out the cutting-edge service cheers again. Tom

Must be Sunday morning. Chris is doing another fantastic video.

Very well done explanation and test. About the only thing I could have hoped for more was seeing you test how full the fast write on the EVO could go and what it would throttle down to for comparison. Regardless, thanks a lot. I'm adding this video to a personal reference playlist. Cheers. 👍

I know very little of computer hardware but try to stay informed when looking to upgrade my PC. This video was very simple and easy to understand. Thank you!

Manufacturers should really make the effort of advertising clearly the differences between both technologies. If you look at these boxes, there is simply no clear mention of the current technology. This is clearly a way for misleading some consumers. Thanks as always for the fantastic video.

I bit the bullet and bought a 1TB samsung QVO about 6 months ago and I am over the moon with reliability and speed on my old G62 HP. like you I will never have trusted a SSD over a year ago due to bad experiences with them a few years back..they all failed within a month ! All I will say I am a convert and if you aint got one then you are missing out on that extra oomph ! And I will add that Samsung must be congratulated on finally converting a serious SSD doubter like me , so well done !

THANK YOU!!!! I understood their differrences clearly. Great work kind sir :D

Your content is very useful. Thanks for all your efforts.

Thank you for perfecto explanation!! I been wondering if I done mistake to buying QVO 1 TB instead of EVO.. This video helped me so much!! My worries are gone. Thank you

I like.... how you present..... your videos.... and give the correct..... technical information........ of the drives that...... you tested

Thanks for the great explanation Chris. I was between the TLC and the QLC drives, and thanks to you I made up my mind, considering the workload I'm going to put the drive through. Kind regards, keep up the good work.

Your explanations are excellent. Thanks man !!!!

WoW :) very informative video.... I personally did not know about the difference :)

Thank you very much. Very useful as usual

You were the first person who explained this so well.

Thank you as always Chris!

WOW, this is so interesting, thanks!

I'm sorry fellas but I'm a HDD guy, it allows me to take shit break while the game loading 👍🏻

This channel is so underrated ! Love your videos.

As always, top of the mark your videos are. Thank you Chris. This was an excellent presentation and very educational. Keep up the good work. I liked yours and subscribed.

now i understand why my friend said to avoid the samsung QVO. very glad i subscribed to this channel.

Awesome video once again. I would have liked to see you adding another 75Gb and see if the TLC would have dropped down at 78Gb or if it would just have kept on going strong and see how big the cache really is, since it wasn't 42Gb. Thanks again...

Thanks Chris, great video. This information is very helpful.

Thank you so much! The video is so informative and helpful, love it !

Presumably at the 42gb gigabyte point the TLC drive had (in the background) offloaded much more from the SLC cache to the main drive than the QLC drive had managed to at the same point, and it was able to do so because TLC is faster than QLC. In fact it seems like the SLC cache in the TLC drive was never actually at capacity, where as the SLC cache in the QLC drive hit capacity after about 45gb copied.

I am a memory expert and I can say you only touched the surface of NAND storage cell technology. I think the biggest thing you missed was that not all substrate dies are equal at a given level; there are SLC that are rated up to 100K writes, but others at 50K or even 10K. One indication is to look at the ECC requirement and see how many bits are expected to be corrected per 512 byte page slice. Therefore, there are MLC chips that are superior to lower quality SLC chips. Further, it should be noted that all NAND cells suffer from unreliability and MUST have a hardware ECC layer implemented, unlike NOR cells which can be rated reliable and require no error correction.

Thanks alot for this video. thanks for explaining all about QLC and TLC. great content. keep up the good work.

Fantastic video, learned more here than I have from any single technology video I can remember.

Hey Chris! I think it would be great if you could also test data retention of SSDs, when they're unpowered. It would probably require a fair bit of time (or maybe not...), but would be worth it.

Oh Lord! Thanks for such a valuable information a always you do Prof. Barnett. And by the way we are talking about endurance and speeds and so on, I wanted to ask you about something I was told by the technician of my enterprise-environment machines recently upgraded with fancy Toshiba and Samsung SSDs (MLC) regards to how in certain way "to help to extend out" the life expectancy and reduce the erase cycles {which I understand are the ones taking "ssd life away"} He suggested to create a Virtual drive in a high quality SD card (preferable over microSDs) or a "linked Folder (I do not even know what that is)" and since the VHD will be taken as an internal device this way Win10 software like OneDrive for instance could be moved off to that location OR the default download folders which we very often as it is intended of course we download and then delete most of the files we put in our PCs. additionally in these VHD contained in the microsd/sd/USBs can serve as "cold storage" or something alike. and in this way we are not hurting the SSDs blocks by deleting a couple of pictures we do not want or that piece of software we downloaded and then we regretted doing it. the whole idea is that save write/erase cycles. ---- SO WOULD YOU MAKE IN THE NEAR FUTURE A VIDEO EXPLAINING TO US HOW TO MAKE IT PROPERLY --- (My assistant's MS-Surface shall appreciate INDEED!). I am polyglot and I swear I cannot even find a moderately well spoken or educated person explaining this topic. I understand that since this once is done there are additional considerations to be done in Registry editor such as booting scripts to mount automatically the drive (the virtual one from the SD card) well thank you very much again for your formidable and HIGHLY VALUABLE INFORMATION IN YOUR CHANNEL. (BY THE WAY WATCH OUT I HEARD YOU SAYING "GONNA, WANNA" THAT IS UNFORGIVABLE FOR AN ACADEMIC PERSON LIKE YOU ;-D)

Clearly presented, no hype, no waffle. Thank you.

Thank you very much Christopher for share your videos with us. Your videos are exelent and have value information. I just imagine how much time you take to make them. Big hug

Very Informative Loves Your's Work 😄😄😄

Excellent comparison. Would be great to see results for the Samsung Pro series alongside these 2!

Thx a lot Chris for making these tests👍

Fantastic, informative video. Thank you for your videos!

Waiting for your Half a Million subscribers soon....💥

Great videos! Pure tech contend " state of art videos"

Thanks for the demonstration and explanation, like to hear more

great content Chris as always. cheers