+1 on the fact that not all SSDs are equal. That is a completely different consideration. There are cheap brands, named-brands that resell other manufacturers's stuff and their are the higher quality brands across each market segment.
What I buy for putting together a computer to be resold is very different from what I buy for my own laptop, which is very different from what I buy for a VM server that will run 24/7 for 10 yrs.
Performance matters about 5th in my list of concerns.
- Size
- Price
- Endurance/durability as spec'd in TBW warranty
- Connection type
- Speed
I won't buy any SSD that doesn't have published endurance numbers. I've contacted some vendors who don't publish and they refused to provide those numbers. That tells me something about the quality of those devices just like a spinning HDD with a 90 day warranty says "this is crap".
To me, all SSDs are so much faster than spinning disks that it really doesn't matter anymore. OSes have been doing all sorts of tricks with spinning disks to make them "feel" faster. Those same tricks don't help nearly as much for SSDs, except to reduce write cycles. SSD endurance is all about write cycles per cell/sector.
There's lots of less-than-truthful marketing out there for storage. WD has taken to calling some of their external storage "black" trying to play on the WD-Black 5 yr warranty HDDs for an external case that happens to be housed inside a black plastic case. They've been calling some SSDs "black" too, when they only have 3 yr warranties and not the greatest TBW endurance numbers. FWIW, a WD-Black HDD is a quality consumer disk with a warranty to match. The next step up gets into the professional/data center HDDs for 30% higher prices. SSDs have a similar split.
- Cheap
- Consumer
- Pro
- Data Center
The prices reflect the underlying technology used (usually). The trick is to catch a sale on a low-end "pro" or high-end Consumer offer from a reputable SSD vendor.
The other trick is to monitor the TBW in the SMART data periodically, so you can predict when only 20% is left and plan a replacement. ....
Code:
=== START OF INFORMATION SECTION ===
Device Model: Micron_1100_MTFDDAV512TBN
...
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 10406
173 Unknown_Attribute 0x0032 098 098 000 Old_age Always - 41
174 Unknown_Attribute 0x0032 100 100 000 Old_age Always - 35
202 Unknown_SSD_Attribute 0x0030 098 098 001 Old_age Offline - 2
246 Unknown_Attribute 0x0032 100 100 000 Old_age Always - 13917089118
247 Unknown_Attribute 0x0032 100 100 000 Old_age Always - 435623544
248 Unknown_Attribute 0x0032 100 100 000 Old_age Always - 363193339
180 Unused_Rsvd_Blk_Cnt_Tot 0x0033 000 000 000 Pre-fail Always - 2480
Micron makes SSDs for other "name brands" you know, like Crucial. The model above is a mid-range consumer that happened to be a deal for a few days. Micron has a PDF file which labels most attributes AND has a 1 page explanation for each.
173 - Average Block-Erase Count
174 - Unexpected Power Loss Count
202 - Percent Lifetime Remaining (by this value, 98% of the lifetime remains)
This value gives the threshold inverted value of the data value below. That is, if 30% of
the lifetime has been used, this value will report 70%. A value of 0% indicates that 100%
of the expected lifetime has been used.
Raw Data (48 bits)
This value is defined as:
[insert complex formula; not really, this time]
Where:
E AVG = Average erase count for a super block (stripe of blocks)
B L = Erase count for which the part is rated (block life)
Attrib 246 isn't in the document, but I'd bet that is the TBW ... 13,917,089,118 ... about 13TB. This is a TLC SSD and a little over 1 yr old. The designed TBW limit is 240TB ... so, 240 / 13 = 18.5 yrs remaining. In theory, if the use patterns for it continue. There is some specific high-write processing that I perform on spinning rust instead of this SSD to reduce the number of write cycles. Seems to be working. Also, never forget that the view the SSD provides to the OS of storage layout is 100% virtual and has nothing, ZERO, nada, to do with how cells are actually allocated into partitions or LVs or zpools. What happens inside these modern SSDs as they try to write balance across all the cells equally hides all those details to the OS and humans.
Sorry for heading off topic so far. Learn about TLC, SLC, MLC, QLC differences in SSDs to understand why QLC probably isn't the best choice unless only price matters.
