Wednesday, February 17th 2021
Western Digital Unveils Entry-level WD Green SN350 M.2 NVMe SSDs
Western Digital announced the new WD Green SN350 series of entry-level M.2 NVMe SSDs. These drives are positioned a notch below the WD Blue SN550 (mid-range), while the WD Black SN850 remains the company's current flagship client SSD product. The WD Green SN350 comes in capacities of 240 GB, 480 GB, and 960 GB. The company didn't detail the underlying architecture, but the drive features PCI-Express 3.0 x4 host interface, and likely features a 4-channel controller architecture. It also appears to feature DRAM cache.
All three capacity variants of the WD Green SN350 offer sequential read speeds of up to 2,400 MB/s. The 240 GB variant offers sequential writes of up to 900 MB/s, the 480 GB variant up to 1,650 MB/s, and the 960 GB variant up to 1,900 MB/s. The company didn't detail the NAND flash type, or endurance numbers. It's backing these drives with 3-year warranties. The 240 GB variant is priced at USD $43.99, the 480 GB variant $54.99, and the 960 GB variant $99.99.
All three capacity variants of the WD Green SN350 offer sequential read speeds of up to 2,400 MB/s. The 240 GB variant offers sequential writes of up to 900 MB/s, the 480 GB variant up to 1,650 MB/s, and the 960 GB variant up to 1,900 MB/s. The company didn't detail the NAND flash type, or endurance numbers. It's backing these drives with 3-year warranties. The 240 GB variant is priced at USD $43.99, the 480 GB variant $54.99, and the 960 GB variant $99.99.
25 Comments on Western Digital Unveils Entry-level WD Green SN350 M.2 NVMe SSDs
The SN550, SN750 and SN850 are all rated 600TBW for the 1TB. Hell, even other QLC drives are better - 665p is 300TBW and P1 is 200TBW. These SN350s had better sell for half the stated MSRP, because SATA M.2s are literally going to be the better pick. Literally. 870 QVO is a 360TBW drive.
Such NAND memory will quickly show memory blocks that wear out and slow down the read latency.
There is little margin for loss of charge, and to compensate for this, extra writes are made without informing the file system, and the extra capacity is lost.
And the data retention is short, so some data loss will occur on drives that have been left unattended.
It is very vulnerable to small, intermittent writes such as logging and virtual memory, and 1GB from a file system perspective can be more than 20GB for NAND memory.
This is a product for those who know how to use it well.
Looking at my OS SSD (about 1 1/2 old) I've got 19 TBW. That's considering that all my work is done on my other 2TB SSD and all my downloads go to a 16TB HDD. If you add downloads and game installs to the SSD you'd be looking at likely double that number.
The 240GB model has a 40TBW life estimate. I wouldn't touch these drives with a 10 foot poll. That's absolutely pitiful no matter how you look at it. "Acceptable" in what way per say? "Acceptable" in regards to the fact that at $44 USD these are going to be more expensive than entry level products from other competitors that also happen to have higher endurance (150TBW on competing models at the same price)?
This isn't some impossible to reach TBW figure, it's something your average consumer can reach in 5 years and an avid PC user in 2-4. Heck you almost reach 40TBW and that's considering your drive was released in 2014, when data requirements were lower. Data requirements increase over time, from the increasing size of games to temp internet files downloaded when you browse the web. This drive is being released now, so it should be assumed that data requirements will be higher than in 2014.
Regardless of that, who doesn't want more endurance? Two drives cost $45 but the one lasts 5 years and the other 15 years and you are telling me that doesn't matter? What a load of crap, you'd have to be crazy to not take the 15 year drive. SSD consume little electricity, even at low capacity you can form a drive pool with your older units. Should you choose to sell the 15 year drive also depreciates less as it has a much larger chunk of it's useful life left. No one is going to buy a used QLC drive with 10% life left.
Like I said, if the SN350 was half the price, it'd be a decent deal. Right now it's smack dab in the middle of the SN550's price range, which is one of the current budget kings that inevitably walks all over it in performance, DRAM be damned. With more than 6x the endurance. The fact that the QLC 660p at 200TBW and 665p at 300TBW have occupied this segment for years tells you exactly how viable this SN350 is at $99.
When we made the transition from MLC to TLC, nobody cared because endurance was still good enough.
Now we have QLC spreading like the plague, which is okay, but creeping under 100 TBW makes me a bit worried. With MLC and TLC we got significantly higher capacities, but now we're slowly getting less and less endurance on the same capacity. I understand manufacturers: more drive failures mean more buyers, but still... 100 bucks for an 80 TBW 1 TB drive is a terrible deal considering that you can get 200-300 TBW 1 TB drives for the same price. This SN350 will be on my "never recommend to anyone" list for sure.
You have to understand the characteristics of NAND memory correctly. You may have to specify that it is a product for your grandmother, but in reality, the more people who understand it, the less misery they will have.
Even in the best case, guaranteeing only 80 writes to a single cell makes data retention look extremely questionable.
Even TLC-NAND memory is inferior to DVD-R in terms of data retention when it is not connected to a power source.
As a side note, if you leave a drive with Windows installed connected to the network, it won't take a year for the NAND to consume 1TB worth of NAND blocks.
If you have a cache buffer with trim and a UPS, you can avoid this, but your grandmother may not understand. If you have a lot of memory, you may also need to turn off hibernation.
On a less important note, 1 to 2 TB is too low an estimate.
LTT recently reviewed a 15TB QLC drive with similar endurance to a 4TB TLC drive.
Here's hoping my 1TB TLC drives last a long time.
My boot drive (a 500GB 970 EVO) has 18TBW and 99% life remaining, while my mass-storage drive (a 4TB Seagate Barracuda) has over 34TBW and is showing no signs of stopping. That's one advantage spinning rust will have over flash for the foreseeable future; better write endurance.
I don't know if it's just randomness for me and the places where I have worked, or if certain workloads can wear out SSDs much faster than their endurance rating. The workloads I'm talking of is code compilation, which generates up to millions of tiny files per day, not many GBs of data, but it seems to give SSDs a lifespan of ~3 years.
BTW; Have you checked the SMART data of your 850 EVO lately, or are you waiting to stumble across corrupted files?
And the funny thing is they never really got rid of the Green HDDs, they just rebranded the Green drives as Blue drives, and bumped the Blue drives up to Blacks and killed off the good Black drives.
Endurance is up to 400 TBW for the 1TB model:
www.westerndigital.com/products/commercial-internal-drives/pc-sn530-ssd
400 TB writing in the SSD's lifespan is more than enough for an average user...
The spec sheet clearly says 80TBW for the 1TB model and 40TBW for the 240GB version.
Not that it really matters. As pointed out before, even 80TBW is a lot for a normal user. My NVMe system drive has been running for over a year continuously and it only has 6TB of written data. It would take me over 10 years to reach 80TB. These drives would work just fine as a normal user's main drive.
I think WD should kill the Green brand, ever since they transitioned to SSDs, their Green SSDs were some of the worst in the market, a HUGE contrast from their Blue and Black drives, the sad thing is that expect to see this drive a LOT in laptops or pre built PCs