SSD Buying Advice

[Davros]

First off a general question:
SSD's wear out over time the longevity is usually quoted in TBW (Total Bytes Written) does this mean reads dont cause wear just writes ?

So the plan originally was to buy a large HDD for my games (because size was more important than speed)
But recently games have been released that require a SSD and I can see this trend continuing.
So I'm thinking about this :

More details here :

https://www.scan.co.uk/products/8tb-samsung-870-qvo-25-ssd-sata-iii-6gb-s-mjx-mlc-v-nand-8gb-cache-read-560mb-s-write-530mb-s-98k-88

click on specifications

Question 1:
So is there any reason not to get this it seems really cheap (less than a lot of 4TB Drives) and I'm wondering if there's a reason for this

Question 2: I still have 1.5TB of nvme space left (yes I know and I am deeply ashamed of myself and have been preying to the Gaming Gods for forgiveness) so I'm thinking if I wait until that's full
prices will have come down. But then again I watched a video about computer news and it said Samsung was going to increase the price of their nand chips so I'm also thinking maybe I should buy it now.
Thoughts?.....

 

[Albuquerque]

Answer 1: No reason you shouldn't get it. There have been dozens of benchmarks, on Youtube and otherwise, showing SATA-interface SSD's getting awfully close to the performance of NVME-interface SSD's for game loading and streaming. Yes, the benchmark numbers will show you an order of magnitude difference in throughput and latency; none of that has really borne any fruit at this point. As part of my statement, I'm also including the myriad DirectIO benchmarks that now exist in the world, and yet still have no explicit bearing on real game performance.

Answer 2: Prices fluctuate all the time, buy when you feel like you want to. What's your current "burn rate" on free space? Is it 1Tb a year? If so, then pffft just wait a year and see what else comes around. Also worth noting: there were 8TB NVMe SSDs for sale at MicroCenter last week for $299. I think it's still for sale at that price, if you have one locally (eg the price is only for walk-in sales, no online / no shipping.)

 

[Davros]

I'm in the U.K so no microscentre for me plus I have no free m2 slots
Also just looked at 8tb nvme drives in my local retailers and they start at £800

 

[orangpelupa]

SSD's wear out over time the longevity is usually quoted in TBW (Total Bytes Written) does this mean reads dont cause wear just writes ?

generally, yes.

but some SSD (iirc one samsung model from years ago) also wears out by itself if the cells never written

as for pricing, the SSD price may be increasing in few months. as supplies stabilizes (not its oversupply)

 

[arandomguy]

It's a sale and likely an actual hot sale (as opposed to a regularly rotating sale that's really the regular price) which does make the price attractive. Albeit I'm from that region so I can't say for certain just how hot a deal it is.

It's worth mentioning though that if you're comparing against the other drives on that site do note this is also a QLC while the others are TLC drives. QLC drives would also inherently be cheaper.

Personally speaking I dislike QLC drives but that's likely something that would result in debate. To keep it short I have skepticism on how well they can handle voltage drift and older data, as well as read/write contention issues which aren't really tested (not practical for reviews).

I certainly would rather spend the normally few tens of dollars more at most) but here it is also significantly cheaper over the TLC alternatives, basically if it's cheap enough than quality can take a back seat.

As another poster mention you should factor in just how soon you actually need all that space. While NAND (and SSD prices) have likely bottomed this cycle (and this Q4 sales season will likely be the lows) and will start to rise they will also hit a new low at the bottom of the next cycle. Barring macro shocks though the next bottom is likely not going to be until something like the 2+ year range, next years prices based on forecasts are going to be higher than now (not counting individual product sales).

generally, yes.

but some SSD (iirc one samsung model from years ago) also wears out by itself if the cells never written

as for pricing, the SSD price may be increasing in few months. as supplies stabilizes (not its oversupply)

I'm not sure exactly what you're referring to but something to keep in mind with SSDs is that the actual cells are written to even without directly user writes.

I'm going to take a stab here if you are maybe referring to the 840/Evo that had notable read speed degradation with old data.

 

[orangpelupa]

It's a sale and likely an actual hot sale (as opposed to a regularly rotating sale that's really the regular price) which does make the price attractive. Albeit I'm from that region so I can't say for certain just how hot a deal it is.

It's worth mentioning though that if you're comparing against the other drives on that site do note this is also a QLC while the others are TLC drives. QLC drives would also inherently be cheaper.

Personally speaking I dislike QLC drives but that's likely something that would result in debate. To keep it short I have skepticism on how well they can handle voltage drift and older data, as well as read/write contention issues which aren't really tested (not practical for reviews).

I certainly would rather spend the normally few tens of dollars more at most) but here it is also significantly cheaper over the TLC alternatives, basically if it's cheap enough than quality can take a back seat.

As another poster mention you should factor in just how soon you actually need all that space. While NAND (and SSD prices) have likely bottomed this cycle (and this Q4 sales season will likely be the lows) and will start to rise they will also hit a new low at the bottom of the next cycle. Barring macro shocks though the next bottom is likely not going to be until something like the 2+ year range, next years prices based on forecasts are going to be higher than now (not counting individual product sales).



I'm not sure exactly what you're referring to but something to keep in mind with SSDs is that the actual cells are written to even without directly user writes.

I'm going to take a stab here if you are maybe referring to the 840/Evo that had notable read speed degradation with old data.

yes that one, but it degrades so much, to be so slow, practically makes the data unreadable.

works again by using full format and writing data again but the time gap between borked and working fine gradually getting shorter and shorter, making the SSD useless.

those with retail unit can update the FW to address this issue. those with OEM unit like me, stuck with old problematic FW

 

[arandomguy]

yes that one, but it degrades so much, to be so slow, practically makes the data unreadable.

works again by using full format and writing data again but the time gap between borked and working fine gradually getting shorter and shorter, making the SSD useless.

those with retail unit can update the FW to address this issue. those with OEM unit like me, stuck with old problematic FW

I'll go into this a bit more but that situation is also why I have general skepticism with respect to QLC drives over TLC drives now as well and how reviews don't (and can't) fully handle SSDs.

The 840/Evo were the first drives to move from MLC (2 bit per cell, but this means 4 states per cell) to TLC (3 bit, 8 states). They were also the last of the planar NAND shrinks, and so cell sizes were tiny (moving to 3D NAND actually increased the cell sizes). They also still used BCH for error correction right before the shift to LPDC.

The firmware fix basically was to periodically refresh the cells, which effectively means to rewrite to the cells, as part of it's background functions. But I don't think 840 was ever given a "fix" as the media attention fixated on the 840 EVO.

But in general all SSDs will perform writes indirect of the user for various background functions.

 

[pcchen]

For casual use (I think in general most gaming counts as casual use) QLC is probably fine, as most QLC drives (including 870 QVO) have SLC cache so small writes do not get into QLC as frequently. However, this still depends on how you use the drive. For example, if you want to frequently install/remove games, it can be a bit problematic. On the other hand, if you just have games installed and leave it there and then ocassionally updated I think it should be fine.

As for price, there's report that Samsung is planning to increase NAND chip prices, so it's probably not going down very soon.

 

[Davros]

Thanks everyone....

 

[hoom]

does this mean reads dont cause wear just writes

As I understand the reads use an order of magnitude or 2 less voltage than writes -> below the level that causes significant degradation.
Automated rewrites or whatever as part of firmware function will presumably cause wear even if not writing much but should be much slower rate as a mostly static game drive vs a system drive.

I actually bought a 4TB 870 QVO drive earlier in the year for same reason of wanting a decent capacity game storage drive with SSD speeds without the outrageous cost of similar capacity in M2/PCIE drive.
The way I see it, for a game you're mostly going to be reading out (relatively) big continuous files like textures & while they don't post outrageous peaks, the QLC drives should consistently max out a SATA6 interface in those circumstances & thats a lot of loading speed.

 

[Albuquerque]

I think there's a few pieces of additional information people are hand-waving off.

Quad Level Cell Life Expectancy: Micron QLC flash has been in the enterprise storage space for a bit more than five years now. For any of you who have purchased storage as a component of a physical server, you've seen these drives billed as "read intensive workload" devices. The storage technology itself is entirely stable and understood; there's no mystery to whether QLC is living a long lfe or not.

SLC caches in QLC drives: These aren't actually separate storage modules, instead the existing flash cells are simply stored with less bits of precision. A flash cell, by itself, isn't necessarily SLC/MLC/TLC/QLC per-se, instead it's the controller logic which can differentiate the charge / voltage levels in the flash cells to determine the data stored therein. As for the cache sizing itself, you'll notice advertised cache sizes are claimed as "up to (xxx) bytes can be reserved for cache". As the drive is filled up, your total available blocks of flash which could be used for caching will diminish.

Automated Rewrites as a function of life: The drive doesn't simply rewrite itself all the time. Rather, metadata is maintained to track large, contiguous blocks of storage for the oldest access time. Beyond a certain threshold, the block is targeted for a garbage collection of sorts, where (in the background) the block of cells will be read and then rewritten. Modern logic will thread these tasks into other pending I/O requests where feasible, but the affect on total write cycles of the cells themselves is incredibly small. By the way, these are still a thing, they're just now part of the larger TBW duty cycle calculation. There are additional TBW's hidden underneath for the drive to maintain itself. If you were to fill a QLC drive up with storage and then set it on a shelf for literally years, you may end up with performance issues or perhaps even data corruption. These drives aren't meant to be long term cold storage, and nobody should be expecting them to act that way.

QLC isn't the end for flash storage, there will be PLC (penta- or five levels) and even more coming eventually. Storing more bits per flash cell is how higher capacity flash storage devices are able to be built and remain affordable.

 

[swaaye]

First off a general question:
SSD's wear out over time the longevity is usually quoted in TBW (Total Bytes Written) does this mean reads dont cause wear just writes ?

So the plan originally was to buy a large HDD for my games (because size was more important than speed)
But recently games have been released that require a SSD and I can see this trend continuing.
So I'm thinking about this :
View attachment 9976
More details here :

https://www.scan.co.uk/products/8tb-samsung-870-qvo-25-ssd-sata-iii-6gb-s-mjx-mlc-v-nand-8gb-cache-read-560mb-s-write-530mb-s-98k-88

click on specifications

Question 1:
So is there any reason not to get this it seems really cheap (less than a lot of 4TB Drives) and I'm wondering if there's a reason for this

Question 2: I still have 1.5TB of nvme space left (yes I know and I am deeply ashamed of myself and have been preying to the Gaming Gods for forgiveness) so I'm thinking if I wait until that's full
prices will have come down. But then again I watched a video about computer news and it said Samsung was going to increase the price of their nand chips so I'm also thinking maybe I should buy it now.
Thoughts?.....

It sounds like a solid drive. Nice write longevity rating. They make quality drives.

Reviews show that write performance degrades to about 170MB/s after 84GB. So filling it in one go won't be much different than writing to a HDD. Reads will always be great however.

SSD prices are basically always decreasing regardless of short term stuff.

 

[Bludd]

my samsung 960 evo 1 tb nvme i bought in january 2017 and has been used as the Windows OS drive + games drive is reported in samsung magician as 10% used and 103 TB written

 

[Davros]

10% used

By that do you mean 10% full or 10% worn out?

 

[Bludd]

By that do you mean 10% full or 10% worn out?

10% worn, is what i understand it to mean but also my available spare is at 100

the takeaway is that its fine for many years still with this usage pattern

 

[Davros]

I have a Kingston HyperX 120gb drive (was a windows boot drive from an older pc and is possibly 10years old) and it's TBW is only 290TB because of its small size
this is how it's doing


ps: the use case for the new drive will basically be it will be written to once and then just reads because as a general rule I dont uninstall games (it makes the Gaming Gods cry)

pps: in an earlier post I said "Also just looked at 8tb nvme drives in my local retailers and they start at £800" forgot to mention there's an 8tb upgrade kit (it's 2x4tb drives) for the Mac pro it's £2,880

 

[Albuquerque]

Apparently my old USB to SATA interface thingy doesn't support SMART request passing for whatever reason. I was going to look at this old Sammy 840 drive "just to see" and, while it's fully accessible, I can't get it to read the SMART hardware statistics. I'll go dig out a SATA cable sometime soon and plug it in directly, if I can find a SATA power adapter cable too...

 

[Davros]

Just disconnect one of your drives and use it's cables (I assume your pc has more than 1 drive) while you read the smart data.

 

[Albuquerque]

No SATA drives in the current rig, only NVMe I think I might even have the SATA controller fully disabled lol... All my other devices in the house are either laptops that only have one SATA port (or less), or are server machines that aren't running Windows so I'd need to actually put forth some modicum of effort to get the proper tooling installed.

Anyway, i gotta go into the attic later this week to go find an old box of documentation, and all my spare modular PSU and SATA cables are up there too. I'll see if I can drag a few down.

 

[orangpelupa]

Btw in my unlucky saga with electronics, SSD always go into read only mode instead of simply went poof like HDD.

The problem is that the read only mode does not correlates to wear level.

Anyway, since I stopped putting 64GB windows virtual memory to SSD, I hadn't got any of my ssd went into read only mode. Actually, hadn't encountered any problem at all, even with super cheap SSD