ssd wear level on 2015 mbp with report included, any advice?

[trfc54]

Ran a DriveDx ssd test with the following results, just wanted to make sure that they are ok? I was a bit perplexed why the ssd lifetime indicator is at 100% whereas the wear leveling count is at 78%.

Computer stats: MacBook Pro (Retina, 15-inch, Mid 2015), 2.2 GHz Intel Core i7,
16 GB 1600 MHz DDR3, Intel Iris Pro 1536 MB, 256 gb ssd

Included them as a txt file, but the quick synopsis:

Overall Health Rating : GOOD 100%
SSD Lifetime Left Indicator : GOOD 100%

Power On Time : 5,670 hours (7 months 26 days 6 hours)
Power Cycles Count : 11,139
Current Power Cycle Time : 47.5 hours

=== DRIVE HEALTH INDICATORS ===
ID | NAME | TYPE | UPDATE | RAW VALUE | VALUE | THRESHOLD | WORST | LAST MODIFIED | STATUS
1 Raw Read Error Rate Life-span online 0x0 200 0 200 - 100% OK
5 Retired Block Count Pre-fail online 0 100 0 100 - 100% OK
9 Power On Hours Life-span online 5,670 98 0 98 - 98.0% OK
12 Power Cycle Count Life-span online 11,139 88 0 88 - 88.0% OK
169 Total Bad Block Count Pre-fail online 0x17714800F00 253 10 253 - 100% OK
173 Wear Leveling Count Life-span online 0x18302AD0214 178 100 178 - 78.0% OK
174 Host Reads MiB Life-span online 82,554,695 (78.7 TB) 99 0 99 - 99.0% OK
175 Host Writes MiB Life-span online 83,842,322 (80.0 TB) 99 0 99 - 99.0% OK
192 Unsafe Shutdown Count Life-span online 253 99 0 99 - 99.0% OK
194 Temperature (Celsius) Life-span online 38 62 30 62 - 45.7% OK
197 Current Pending Block Count Life-span online 0 100 0 100 - 100% OK
199 UDMA CRC Error Count Life-span online 0 200 0 200 - 100% OK
240 Vendor Specific Life-span online 0x0 100 0 100 - 100% OK

 

[chekie]

The software has already told you:

Overall Health Rating : GOOD 100%
SSD Lifetime Left Indicator : GOOD 100%

 

[trfc54]

The software has already told you:

Overall Health Rating : GOOD 100%
SSD Lifetime Left Indicator : GOOD 100%

Yes, but is that consistent with the 78% wear level count? That's why I was expecting a worse lifetime left indicator percentage.

 

[chekie]

This my DriveDX report (MacBook Pro 13 late 2013 256GB SSD) on 11-22-2018 when I retired it as a backup machine.

It looks like I used it a lot harder than you did. (184.6 TB written in 5 years vs your 78.7 TB in over 3 years). And my DriveDx overall assessment is still:

Overall Health Rating : GOOD 100%
SSD Lifetime Left Indicator : GOOD 100%

And I don't have any problem with its performance at all. It still runs as fast as new. So I don't think you have anything to worry about.
[doublepost=1555265364][/doublepost]I see your concern is with Wear Level.

SSD does have finite life span. It will eventually die if you write enough amount of data.

The most crappy SSD on the market usually have at least 1000 P/E cycles. This means you can write 1000 x SSD capacity amount of data before it shows issues related to age. Samsung SSD used by Apple usually have 2000 to 5000 cycles. Lets be pessimistic and assume 2000 cycles. In your case, you would need to write about 500 TB (2000 x 256 GB) for it to begin to die.

I am not sure how DriveDX calculates wear level. My guess is it is related to amount of data you write to the drive. This means as long as you use it, the drive will inevitably show some wear. Will it fail when it gets down to 0%? Not necessarily. It just means you have a lot of data written to it and it may fail.

 

[trfc54]

Ok, since I bought this mpb used just recently I was concerned I may need to replace the drive, but it seems you have quelled my concerns a bit

 

[treekram]

The use of SMART attributes (what DriveDX and other similar programs use) isn't standardized. The hard numbers (hours, bytes, power-offs, etc.) are likely accurate but the other numbers may not be. To me, the 99% and 100% figures are unrealistic. The "Host Writes MiB Life-span online" attribute being 99% with 80TB written is not realistic for this SSD. I would expect the total writes to be about 200TB, and that's 60%. The Wear Leveling Count Life-span online" figure of 78% is believable and a better indicator of remaining SSD life. Overall, I think you got a good used MBP from the SSD standpoint.

 

[trfc54]

The use of SMART attributes (what DriveDX and other similar programs use) isn't standardized. The hard numbers (hours, bytes, power-offs, etc.) are likely accurate but the other numbers may not be. To me, the 99% and 100% figures are unrealistic. The "Host Writes MiB Life-span online" attribute being 99% with 80TB written is not realistic for this SSD. I would expect the total writes to be about 200TB, and that's 60%. The Wear Leveling Count Life-span online" figure of 78% is believable and a better indicator of remaining SSD life. Overall, I think you got a good used MBP from the SSD standpoint.

Do you think it's usable for a few more years at least? My uses: Xcode/VS programming, some safari surfing. Not intending to run VM's heavily or do any photo/video editing.

 

[treekram]

Do you think it's usable for a few more years at least? My uses: Xcode/VS programming, some safari surfing. Not intending to run VM's heavily or do any photo/video editing.

Based on what DriveDX is reporting, the SSD is at somewhere near 22% to 40% (the 22% is what the manufacturer believes and the 40% is based on a comparable Samsung SSD's write endurance since the 1% is not realistic) of it's life expectancy. As I mentioned earlier, I think something closer to the 22% is more likely. I would think that the web surfing would incur more disk writes than the programming would. If you're concerned about it, get an ad blocker or you can buy an external SSD and boot from it when you want to do more intensive web surfing and watch videos over the web. But if you're doing programming, I would think it would be a major hinderance if you try to avoid using the web to find solutions to programming issues that are bound to come up.

 

[trfc54]

Based on what DriveDX is reporting, the SSD is at somewhere near 22% to 40% (the 22% is what the manufacturer believes and the 40% is based on a comparable Samsung SSD's write endurance since the 1% is not realistic) of it's life expectancy. As I mentioned earlier, I think something closer to the 22% is more likely. I would think that the web surfing would incur more disk writes than the programming would. If you're concerned about it, get an ad blocker or you can buy an external SSD and boot from it when you want to do more intensive web surfing and watch videos over the web. But if you're doing programming, I would think it would be a major hinderance if you try to avoid using the web to find solutions to programming issues that are bound to come up.

Thanks, it would mostly be for static type sites like stack overflow and not too much video watching. Maybe getting an external ssd like this Samsung 500gb one then wouldn't be bad if I knew I was going to be doing a lot of media streaming: https://www.amazon.com/Samsung-T5-P...&pf_rd_p=9bc9d775-b810-58dc-aff0-248ecaa49afc

I use Ghostery right now for adblocking on safari as well.

 

[chekie]

Based on what DriveDX is reporting, the SSD is at somewhere near 22% to 40% (the 22% is what the manufacturer believes and the 40% is based on a comparable Samsung SSD's write endurance since the 1% is not realistic) of it's life expectancy. As I mentioned earlier, I think something closer to the 22% is more likely. I would think that the web surfing would incur more disk writes than the programming would. If you're concerned about it, get an ad blocker or you can buy an external SSD and boot from it when you want to do more intensive web surfing and watch videos over the web. But if you're doing programming, I would think it would be a major hinderance if you try to avoid using the web to find solutions to programming issues that are bound to come up.

Xcode actually writes like crazy to the disk.
When I use Xcode all day, running simulator every few minutes to test things, it writes to disk ~100 GB per day. Not sure why.
In comparison, when I do the same thing with Android Studio except with physical Android phone for testing (or when I am just surfing the web stuff), disk writes are only about 10 ~ 20 GB per day.

 

[treekram]

Xcode actually writes like crazy to the disk.
When I use Xcode all day, running simulator every few minutes to test things, it writes to disk ~100 GB per day. Not sure why.
In comparison, when I do the same thing with Android Studio except with physical Android phone for testing (or when I am just surfing the web stuff), disk writes are only about 10 ~ 20 GB per day.

I can see where the Simulator would write a lot of data. When I was doing more iOS programming, I tended to use the Simulator less as time went on because of issues in using it - one of which was that it proliferated so many instances of the app - with all of it's files on the disk. You bring up a good point - if you do iOS programming and want to reduce SSD wear, use the iOS device vs. the Simulator.

There is a point where trying to avoid SSD wear becomes non-productive. Maybe buying an external SSD is too much but on the other hand, if you use it as a clone and it serves as a backup which you might not otherwise have, then that's a good thing. (Your cloning strategy can be such that you add bookmarks, etc. on the internal SSD, and clone that to the external SSD and whatever stuff you have there, which also include cookies, would be deleted any time you refresh from the internal SSD to the external SSD. And actually removing cookies that you gather by shopping for stuff may be a good thing as well.) But for people who don't like to follow such a structured regimen, it probably wouldn't work so well.