MicroSD options, including MLC cards

[Nigel]

Are they using this tech in micro SDs though or are the micro SDs just regular TLC chips? Everything I've read here has referred to SSDs unless I've missed something...

The 256GB Samsung Evo microSD is using 48 bit V-NAND. Some sources say it is TLC V-NAND, supported by it's relatively slow access speeds: http://www.tomshardware.com/news/samsung-microsd-256gb-evo-plus,31773.html

 

[Deacon]

This white paper from Samsung refers to V-NAND and MLC in the same context - ie this tested V-NAND MLC:

http://www.samsung.com/us/business/oem-solutions/pdfs/V-NAND_technology_WP.pdf

They're certainly comparing it to MLC planar/2D NAND, and using it as short-hand for 2bit V-NAND. You'll notice that they only use the MLC short-hand in the charts. In the actual writing they refer to it more correctly as "2bit" and "3bit" V-NAND, though as primarily a technical marketing document toward SSD manufacturers, they don't really delve into any depth on that difference. Regardless, that's not the unsupported misinformation that @Nigel was spreading while baiting with the following claim: "Samsung have two types of 3D NAND, their Evo range uses TLC cells and their Pro range uses MLC cells, just like their planar NAND chips."

I've just seen the price of those 256GB Samsung microSD cards - jeez!

No joke. That's why I'm said if they can get to the point where it's more affordable then I don't see why it wouldn't take over as the go-to option for dashcams. The problem is that neither on the product page nor in their press release from May 2016 does Samsung specify whether the V-NAND they're using in their 256GB EVO+ microSD cards is 2bit or 3bit V-NAND. So it's hard to know for sure what their strategy is. Maybe it's 2bit and therefore they can improve in the future with 3bit to bring costs down. I doubt it, though, or else they'd be bragging about that, too, as they would for SSD's. I imagine it's most likely already 3bit, which won't have quite the inherent major endurance advantage over MLC planar NAND, which may explain why they're still voiding/limiting the warranty when used in dashcams. If so, only time will tell how the endurance really is and whether the warranty will even be a concern. With such large capacities it should really cut down on the number of writes, and even if the endurance is cut in half, it should still be at least comparable to MLC (planar NAND) and maybe still be superior.

In the meantime it still doesn't seem to be legitimately available on Amazon, leaving you with a $250 price tag if you try to order it directly from Samsung. So someone like me will have to go ahead and wait for availability to increase and price to decrease.

 

[Deacon]

The 256GB Samsung Evo microSD is using 48 bit V-NAND. Some sources say it is TLC V-NAND, supported by it's relatively slow access speeds: http://www.tomshardware.com/news/samsung-microsd-256gb-evo-plus,31773.html

Please stop "contributing" to this thread. You're only causing confusion with your sloppiness and speculation.

First, it's the EVO+ or EVO Plus, not the Evo. There are multiple lines of EVO cards, and they are not the same, so get it right. Second, it's 48-layer, not 48-bit. Get it right. Third, Samsung makes no reference to it as TLC V-NAND. Do not mix thoughts in blogs with actual facts from the manufacturer. Fourth, there is no mention there of "access speeds" at all, which is appropriate since that's not a valid stat or rating, much less anything about any perceived slowness.

Seriously, either hold yourself to a higher standard or drag your keyboard across some other thread.

 

[Deacon]

They normally refer to the MLC 3D NAND as "3-bit V-NAND"

Get out. You're done here. Both 2bit and 3bit V-NAND are referred to by Samsung as MLC. And regardless, the MLC designation does not translate directly between planar NAND and V-NAND. Any attempts to equate them are only going to cause confusion. Leave that to the bloggers and out of this thread.

 

[DrekiTech]

Saw this on Reddit earlier. Looks like we'll be getting larger MLC cards in the near future based on 3D Nand. Link.

I can't imagine it'll be cheap.

 

[Deacon]

That's nuts. Quite the list of specs. You're right I can't imagine it'll be cheap! I'm really hoping Samsung's V-NAND cards turn out to be as reliable and consistent as they should be in theory. Makes MLC somewhat irrelevant since it's a different design from planar and 3D NAND and should be able to withstand far more write cycles. But that's in theory. Seems like they're being more conservative and giving it something like 3x to 5x the number of writes and are still pricing it quite high.

Maybe since ADATA is coming to play with traditional 3D NAND and in MLC form, it'll help drive prices down. It's nice to see these kinds of technologies being announced and finally, on occasion, emerging into reality.

 

[Billy187]

Will you please remind me of the link to that site that claims they have it on good authority from someone at Lexar that they're hiding the MLC status of their 633x cards and explains how they're breaking through barriers by offering 256GB MLC microSD while the competition hasn't been able to break 64GB?

Because there's nothing to support it other than your claim of a claim. Which is nothing against you or whoever the other person is who's making the claim, of course. Just that I'm rather skeptical as all evidence is to the contrary.

I came across this discussion whiles trying to figure out why my 32gb lexar 633x failed spectacularly a few days back- after less than a month of use! However, it was used in my phone, a Motorola G3 and set as internal storage. Oh, and yeah, it entered that dreaded write protection mode too! I highly, highly doubt the lexar 633x is an MLC rated card.

After going through this thread, I'm now considering something along the lines of Adata Premier Pro and Transcend Ultimate lines- as the Transcend High Endurance line might be a tad too slow for me!

 

[Deacon]

Out of curiosity what are you doing that requires (or benefits from) more than 25MB/sec or so?

 

[Billy187]

Out of curiosity what are you doing that requires (or benefits from) more than 25MB/sec or so?

I'll be using the card in my phone running Android 6. 0. 1 and will have it adopted as interal storage. I usually have several moderately heavy apps/ games open simultaneously from the card, so its usually quite busy all the time. I feel I need the fastest sd card possible to prevent the inherent lag that will be associated with lower read/ write speeds-without buying another potential lemon.

 

[reverend]

It must be pretty hard buying genuine memory cards in Ghana?

If the Lexar card failed in less than a month it has a lifetime warranty for replacement (assuming it's not fake).

For phone use you're more interested in random write performance than sequential write.

 

[Billy187]

It must be pretty hard buying genuine memory cards in Ghana?

If the Lexar card failed in less than a month it has a lifetime warranty for replacement (assuming it's not fake).

For phone use you're more interested in random write performance than sequential write.

Very hard. But then I did buy it off Amazon whiles in the US.

I have contacted Lexar but apparently I'll have to pay for shipping both ways -an option so ridiculously expensive I'd be much better off buying a new sd.

Would a device mostly involved in random write benefit from the reliability a MLC and ECC enabled sd card would offer?

 

[Nigel]

Would a device mostly involved in random write benefit from the reliability a MLC and ECC enabled sd card would offer?

Yes, it will live for around 2.5 x longer.

It is worth checking the specs/reviews carefully if you are going to do a lot of random access, some decent cards that are good for sequential access are very slow compared to some others. microSD cards are not normally designed to do well at random access since that is not how most people use them.

I doubt you would use it enough to wear out a normal TLC card as long as it is a decent sized one. The larger the card the longer it will last since the wear levelling will distribute the wear evenly across the whole card, thus a TLC card twice the size of an MLC card will last almost as long.

MLC cards are almost always significantly faster though so I think you have already decided to go for MLC!

 

[Deacon]

Added ADATA.

 

[neilmcl]

Any views on the Lexar High Endurance card?

 

[Deacon]

Did you read the original post?

Lexar doesn't offer MLC, and their High Endurance line is only warranted for 2 years.

 

[Gollan]

Those shipping times for both the Transcend and Lexar 64 GB High Endurance... Are there other reliable places to get these (I'm in Canada) or should I just get in line with Amazon?

 

[Deacon]

Sorry I have no clue about the best places to get stuff in Canada but I'm sure there are local options, right? I guess it depends on how soon you need cards. I really wouldn't bother with the Lexar high endurance 64GB. No real point. Either go with a proper MLC card in the first place or go with high capacity card (128GB+) with a decent reputation. Transcend 400x 128GB, maybe? PNY and Lexar also have decent high capacity options for less.

 

[CB1100FER]

I ordered two of those Lexar cards through Amazon.ca on the 22nd of Jan and took delivery on the 25th. It said the same thing at the time.

 

[neilmcl]

Amazon UK also states a 1 to 2 month lead time for the Transcend, obviously in short supply, the main reason I went for the Lexar instead.

 

[jokiin]

There's a shortage of flash memory at the moment, that is driving the price up also