Unsavory Flash Swap: Re-Testing Crucial’s P2 SSD After QLC Downgrade

legcramp

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https://www.tomshardware.com/features/crucial-p2-ssd-qlc-flash-swap-downgrade

Crucial’s P2 wasn’t much of a contender for the title of the Best SSD when it first launched, but now it’s firmly on our do not recommend list. Recently, Crucial decided to swap out the P2’s TLC flash with slower and less-endurant QLC flash, making the new P2 much worse than the original version. For instance, the QLC version of the drive is nearly four times slower at transferring files than the original, read speeds are half as fast in real-world tests, and sustained write speeds have dropped to USB 2.0-like levels of a mere 40 MBps. That’s slower than most hard drives. Unfortunately Crucial made the change without altering the product name or number or issuing an announcement. Crucial claims that the P2 will live up to its specs because the company baked the performance of QLC flash right into the spec sheet at launch. But those specs don’t match the performance you’ll see in numerous reviews of the originally-shipping drives, resulting in yet another misleading component swap from an SSD manufacturer.


Sound familiar? Just as Adata has been under fire for deceptive tactics, Crucial is now in the hot seat for doing the same. Unlike Adata, Crucial has kept the P2’s SSD controller the same, but swapping TLC flash for cheaper, slower, and less durable QLC can be even more detrimental to performance.

Changing components in any product can happen due to a variety of reasons, like to assure component supply or cut costs, but now even the more reputable SSD manufacturers are becoming more aggressive. While these companies say the modified SSD will meet or exceed the specs of the original, this is mainly true for only one portion of an SSD’s performance — the synthetically measured sequential performance of the SLC cache. That doesn’t reflect the true performance penalties that can occur during real-world use.


Depending on the modification to the initial design, the performance ramifications can be very deceiving if you don’t know what to look for. While the sequential read and write performance can be in line with the spec sheet, random performance and sustained write speeds can vary greatly and severely impact real-world performance. That’s bad news for new buyers on the hunt for their next storage upgrade, especially if they’ve read reviews with higher benchmarks of a drive with the same name that isn’t, well, the same drive they’ll purchase at retail.

In the case of Crucial’s P2, we typically don’t expect companies that make their own NAND to engage in this practice. However, Crucial did set a precedent last year when it released a second SKU of it’s BX500 when it swapped from TLC to QLC NAND. The issue this time around is that the company hasn’t changed the model number or branding at all. Instead, these new P2 SSDs secretly replace the original model we received for review.


Crucial says the P2 lives up to the P2’s specs because it accounted for lower QLC performance when it launched the drives. We did notice the abnormally low performance specs during our initial review: The drive consistently beat its spec’d performance, leading us to believe something was ‘off.’ The 500GB model was only rated to deliver write speeds of up to 940 MBps, which didn’t line up with what we saw in our testing as our sample managed to dish out writes of over 1.8 GBps.


This left us with an uneasy feeling when it came to the future of the P2, and now we know the reason. While these new QLC P2 variants may live up to the company’s spec sheets, just like we saw with Adata’s XPG SX8200 Pro, they most definitely do not live up to the original’s performance. Unfortunately that means the benchmarks you’ll see in every review of the original P2 SSDs paint a misleading picture that isn’t representative of the actual performance you’ll get with the drives.
 

hititnquitit

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What is wrong with these knucklehead companies? Ill bet the price hasn't changed either. This is far worse than Adata in that they make their own friggin nand and they obviously planned this weak shit from the get go. Nothing like two of the three ssd companies you thought were solid, turning out to be complete douche bags. Just waitin on Samsung to complete the trifecta, ha! Can i pick em or what?! 😂
 

ncjoe

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well, I just happened to buy a m.2 p2 500gig crucial drive around jun 1 ... it doesn't have the
uk/ca symbol ... but has the same fw # as the newer qlc m.2 .... so wondering If I have the
qlc or tlc drive , it there a way to know with software test ? or have to remove m.2 from motherboard ?
 

yourgrandma

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What is wrong with these knucklehead companies? Ill bet the price hasn't changed either. This is far worse than Adata in that they make their own friggin nand and they obviously planned this weak shit from the get go. Nothing like two of the three ssd companies you thought were solid, turning out to be complete douche bags. Just waitin on Samsung to complete the trifecta, ha! Can i pick em or what?! 😂
Samsung is already doing stupid crap like this like with their 980 pro being (3bit)TLC and instead of (2bit)MLC unlike all of their of previous pro series but they still call it "MLC".
 

Armenius

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well, I just happened to buy a m.2 p2 500gig crucial drive around jun 1 ... it doesn't have the
uk/ca symbol ... but has the same fw # as the newer qlc m.2 .... so wondering If I have the
qlc or tlc drive , it there a way to know with software test ? or have to remove m.2 from motherboard ?
Use DiskBench like Tom's did to test the drive's speed. If it's TLC it should be hitting 400-500 MB/s.
 

GoodBoy

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Samsung is already doing stupid crap like this like with their 980 pro being (3bit)TLC and instead of (2bit)MLC unlike all of their of previous pro series but they still call it "MLC".
TLC is faster (I thought) so that is like they are mislabeling it as worse than it is, so going in the opposite direction...
 

DPI

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Samsung is already doing stupid crap like this like with their 980 pro being (3bit)TLC and instead of (2bit)MLC unlike all of their of previous pro series but they still call it "MLC".
Really not comparable to post launch bait&switch to inferior NAND and/or controller, after reviews are already set in stone.
 
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Armenius

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TLC is faster (I thought) so that is like they are mislabeling it as worse than it is, so going in the opposite direction...
The 980 Pro is faster than the 970 Pro because of PCI-E 4.0 and new controller, not because of the NAND. Look at past reviews of NVMe drives on PCI-E 3.0 and compare them by NAND type.

https://www.storagereview.com/review/samsung-970-pro-1tb-review

The 970 EVO uses TLC, for comparison.

1629131247783.png


1629131331593.png


1629131362225.png
 

Flogger23m

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Really not comparable to post launch bait&switch to inferior NAND and/or controller, after reviews are already set in stone.

Yeah, the problem is this downgrade appears to be massive. And it makes purchasing decisions harder. All but one of my SSDs have been Crucial, and they've all been great. Not top of the line, but a good balance of speed, reliability and price. I'll now have to question Crucial purchases going forward to ensure they didn't downgrade to a garbage product right before I purchase.
 

DPI

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Yeah, the problem is this downgrade appears to be massive. And it makes purchasing decisions harder. All but one of my SSDs have been Crucial, and they've all been great. Not top of the line, but a good balance of speed, reliability and price. I'll now have to question Crucial purchases going forward to ensure they didn't downgrade to a garbage product right before I purchase.

I've avoided Kingston everything since the V300 debacle. Crucial still makes a lot of good products, so perhaps I'll just avoid their SSD's. Not that my one vote matters much.

I understand the business case for these companies wanting to swap to cheaper components to increase their margins, and it's certainly their prerogative, but when it's a purposefully undisclosed change then it's kinda scummy. They're making a calculation that "most customers won't know or notice the difference, and the extra margin will far outweigh any minor PR blowback." And sadly they're probably right.
 

Zarathustra[H]

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Samsung is already doing stupid crap like this like with their 980 pro being (3bit)TLC and instead of (2bit)MLC unlike all of their of previous pro series but they still call it "MLC".

I don't like that Samsung has moved their Pro line from MLC to TLC either, but it really isnt the same thing. Samsung introduced a new model with different specs. Crucial severely downgraded the specs on a model already on the market without informing anyone or making it apparent anywhere on the product.
 

Zarathustra[H]

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TLC is faster (I thought) so that is like they are mislabeling it as worse than it is, so going in the opposite direction...

All else being equal:

SLC > MLC > TLC > QLC

That said, controllers and performance workarounds continuously improve.

Initially ~2009-2012 SLC was enterprise grade expensive stuff for write endurance. Consumer drives used MLC and often failed prematurely (OCZ I'm looking at you!)

Over time controllers, wear leveling and NAND quality improved sufficiently, especially with the introduction of 3DNand, that SLC was no longer needed (outside of small on drive caches) MLC became the new standard for high write endurance enterprise drives, and TLC became the new consumer standard. And the new consumer TLC did way better than early consumer MLC.

I think we are now at another inflection point. MLC is probably slowly being phased out. TLC will be the new high write endurance enterprise stuff, and QLC will become the new consumer stuff. QLC drives are stilll a bit on the shitty side today, but they are improving, and for general consumer use they are probably fine. prosumers and gamers will still want TLC, and most extreme enterprise applications will likely still want MLC, but I don't think we are far off from another shift, where TLC is the new enterprise standard, and QLC becomes the new consumer standard across the board.

We just aren't quite there yet.
 

Zarathustra[H]

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Thinking a little about this, it would be interesting if some SSD maker came up with a controller that could dynamically shift the drive between different bit level NAND and then storage tier it.

Write everything MLC to begin with. The files that sit longer, gradually get storage tiered down to TLC offline. If they sit even longer, they gradually get storage tiered down to QLC.

Knowing what drive size to advertise and how much free space to display would be difficult, as it would constantly be changing, but it would be a really cool design, because that way youd get good performance on the frequently re-written stuff, and the older stuff that sits would take up less space without much of a performance penalty.
 
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Armenius

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All else being equal:

SLC > MLC > TLC > QLC

That said, controllers and performance workarounds continuously improve.

Initially ~2009-2012 SLC was enterprise grade expensive stuff for write endurance. Consumer drives used MLC and often failed prematurely (OCZ I'm looking at you!)

Over time controllers, wear leveling and NAND quality improved sufficiently, especially with the introduction of 3DNand, that SLC was no longer needed (outside of small on drive caches) MLC became the new standard for high write endurance enterprise drives, and TLC became the new consumer standard. And the new consumer TLC did way better than early consumer MLC.

I think we are now at another inflection point. MLC is probably slowly being phased out. TLC will be the new high write endurance enterprise stuff, and QLC will become the new consumer stuff. QLC drives are stilll a bit on the shitty side today, but they are improving, and for general consumer use they are probably fine. prosumers and gamers will still want TLC, and most extreme enterprise applications will likely still want MLC, but I don't think we are far off from another shift, where TLC is the new enterprise standard, and QLC becomes the new consumer standard across the board.

We just aren't quite there yet.
2-bit MLC is being phased out due to consumer demand for more capacity at a cheaper price. It seems that these days 1TB is becoming the "middle ground" when it was 512GB not too long ago, and it looks like that may become 2TB in the not-too-distant future.

I'm fine with TLC drives for the things I do, but given the run QLC has largely had in the market so far you would never get me to buy one for my own usage.
 

Zarathustra[H]

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I'm fine with TLC drives for the things I do, but given the run QLC has largely had in the market so far you would never get me to buy one for my own usage.

I wouldn't say never. I agree, they are not there to where I would buy one today, but absolutes always come back to bite you in the ass.

You never know, with controller optimizations, and more optimized cache sizing, etc. they may be able to make decent QLC drives in a couple of years.

I'm actually considering putting TLC drives in my server right now, something I never thought I'd say.
 

lopoetve

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Thinking a little about this, it would be interesting if some SSD maker came up with a controller that could dynamically shift the drive between different bit level NAND and then storage tier it.

Write everything MLC to begin with. The files that sit longer, gradually get storage tiered down to TLC offline. If they sit even longer, they gradually get storage tiered down to QLC.

Knowing what drive size to advertise and how much free space to display would be difficult, as it would constantly be changing, but it would be a really cool design, because that way youd get good performance on the frequently re-written stuff, and the older stuff that sits would take up less space without much of a performance penalty.
They have this for enterprise drives. And some home, but more expensive ones. Normally it's an SLC cache dynamically allocated from the pool of available cells. Generally it's 2 layer only though - SLC and then TLC.
 

lopoetve

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I wouldn't say never. I agree, they are not there to where I would buy one today, but absolutes always come back to bite you in the ass.

You never know, with controller optimizations, and more optimized cache sizing, etc. they may be able to make decent QLC drives in a couple of years.

I'm actually considering putting TLC drives in my server right now, something I never thought I'd say.
I bought a few for a multi-tiered storage solution. 4x QLC in SSD-aware R5 for tier 3, 4x MLC in Tier-1, and 2xNVMe MLC for Tier-0. It's working well so far. For the capacity, they're good at it. And most IO comes from the MLC and NVMe drives.
 

Sycraft

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2-bit MLC is being phased out due to consumer demand for more capacity at a cheaper price. It seems that these days 1TB is becoming the "middle ground" when it was 512GB not too long ago, and it looks like that may become 2TB in the not-too-distant future.

I'm fine with TLC drives for the things I do, but given the run QLC has largely had in the market so far you would never get me to buy one for my own usage.
Also has to do with what performance/capacity you can get with a given chip size. Enterprise drives are basically all TLC these days, despite the lower endurance. Why? Because they just overprovision even more to make up for it. Net effect bigger drive, less cost, and still great write endurance. The amount of bits per cell itself doesn't really matter. What matters is do they have a good configuration to be able to sustain speeds and to give good endurance, with good being relative to the product level (consumer drivers don't need 3 DWPD of endurance or anything).
 

ElementDave

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So in fact it's really a two-bit drive with 4-bit (QLC) NAND and a storage capacity insufficient for the amount of bullshit produced by the industry. Is that an accurate summary?

The product pages on Crucial's site don't say anything about the type of NAND. I don't expect to see much technical information on Micron's consumer brand site, but there should be a data sheet buried somewhere with the basics. None found. Any mention of NAND technology is hidden in marketing fluff pieces such as the Crucial P5 Plus press release. Here the P5 Plus PCIe SSD is advertised with 176-layer 3D TLC NAND. That's a different drive and used only as an example.

There were two one-star customer reviews (of two total) left for the 2TB model of the P2, both of which express anger about the lack of transparency and deceptive marketing.

Crucial P2 2TB PCIe M.2 2280SS SSD

Pissed off customer wrote:
Micron silently exchanged their DRAM/TLC version of the P2 to a QLC, DRAMless version. No communication of this change. No change in price for a definitively inferior product. We previously deployed Micron products at ~500 monthly volume, and we will absolutely not be doing business with them anymore.
Micron's canned reply:
Merchant Response
At Crucial we use Micron Manufactured NAND, drives are tested to verify that they meet or exceed all internal design requirements and published drive specifications. Currently the P2 is primarily based on QLC NAND. However, different NAND technologies, like TLC, may be used depending on material availability.”

The PC industry has gone down hill since its definitive transition to full-blown crazy with complete rebranding of product lines and redecoration with RGB lights and racing stripes intended to capture the gaming market.
 
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deruberhanyok

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It’s bait and switch in every way except technically, unfortunately.

That’s why they are pointing at the spec sheet and saying “see? We never claimed higher performance than this.”

totally shitty move on their part though. What’s the point of using nvme if the drives are gonna be so slow anyways?
 

ncjoe

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Use DiskBench like Tom's did to test the drive's speed. If it's TLC it should be hitting 400-500 MB/s.
well toms put together a 90gig pile of assorted files , I don't have time for that ....
to bad toms didn't test using crystaldiskmark or as ssd benchmark... I have those installed and
shown difference between the to different versions of drives...
 

wyqtor

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Samsung is already doing stupid crap like this like with their 980 pro being (3bit)TLC and instead of (2bit)MLC unlike all of their of previous pro series but they still call it "MLC".
In that case, why wouldn't you just get an EVO?
 
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