MX500, very high write amplification

Kilobyte Kid

Re: MX500, very high write amplification

Intel RST (the AHCI driver provided by Intel) versions other than 12.9 would not get installed on Windows 10 on the previously mentioned Intel H77 chipset.


After installing them, I disabled the "Link Power Management" option in their control panel and rebooted as instructed there. This could possibly be the reason why Power On hours didn't rise as real-time hours, and a possible indirect reason why I was having issues with the drive's write amplification and consequently excessive NAND wear for the amount of writes performed by the Host.




I have not performed other changes for now (the P2P program is still active in "seeding" mode), but I've disabled the benchmarking program which was keeping the SSD actively working. In the next hours it should become clearer if this will solve the problem. If it will, this is still something that should be taken care of by the SSD (firmware), though.


EDIT: Unfortunately, that option did not result in any improvement in the behavior of the SSD.

Kilobyte Kid

Re: MX500, very high write amplification

Unfortunately so far I haven't been able to determine any clear software cause to the very high write amplification phenomenon seen.


On the other hand, after collecting SMART attributes at a rate of 1/minute for a few days, it appears there is a correlation between write amplification and the Current Pending ECC Count. It seems unlikely to me that this is something that would be directly software-caused.




So, summing up what I have observed so far:


  • Power On Hours Count appears to increase faster (closer to real time) when a certain amount of load (even read-only load) is put on the SSD.
  • A continuous high read load appears to immediately defer this write amplification phenomenon for a while, but does not completely eliminate it.
  • On the long term, the high write amplification seems to be correlated with the appearance of pending ECC errors.
  • Turning off Aggressive Link Power Management (DIPM/HIPM) from Windows or the chipset AHCI driver does not seem to affect the behavior of the SSD.
  • This might or might not be related, but my Crucial MX500 came from the factory with a M3CR020 firmware, which I understand was not publicly released on the Crucial website. The currently installed firmware is the latest (M3CR023).

As a bonus, here are the latest SMART attributes from Crucial Storage Executive:




Wear leveling count increase for the past few logged days:


TimestampBlock wear-leveling CountHost GiB writtenGiB deltaDays deltaGiB/day
2019-03-15 01:36:06784643.4   
2019-03-17 08:49:13794675.732.312.3014.041
2019-03-18 16:11:52804706.230.461.3123.296