I got a new adapter. I applied the Kapton tape. No heatsink. It works x4. Initially, it reaches 2800-3000 RW but after a couple of min. Diskspped downgrades W to 1300. I guess the EVO controller detects the heat and slows down the speed. So far no restarts, all good. Finger's crossed. The heatsink was touching the iMac body and probably bending the adapter and leading to weak connection or shorting.There is no adapter on the photoI use the right adapter. Firmware updated blade.
heatsink - https://www.amazon.co.uk/gp/product/B073RHHYCM/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
adapter - https://www.amazon.co.uk/gp/product/B01CWWAENG/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
I think the problems are:
1/ probably faulty adapter
2/ Most likely 970 Plus blade doesn't need a heatsink as it already has copper plates underneath the stickers.
3/ This heatsink probably touches something and shorten. If any heatsink is to be used with this particular blade, it should be one-sided and no more than 3mm in my opinion.
4/ Monterey issue. Some users report speed downgrade to x2 after Monterey upgrade. I'm curious to hear more people.
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iMac (Retina 5K, 27-inch, 2017) CPU and NVME SSD Upgrade Pitfalls and Tips
- Thread starter rxs0
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Ok good to hear! If you keep the test speed on is normal that drops..They have limited cash size which if gets full it will drop the speed! And I think you have the old version of Evo since your drop speed is around 1500! New ones are a bit faster and bigger cash size but when they drop speed it become about 800 and they get more heat!
Well I dont know if Kapton tape is really needed since in new design of adaptor they mention that they add a layer to prevent problems from that point! Still using Mojave? Did you add adhesive or not yet?
By the way find out what temperature you get after few min speed test!
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970 EVO Plus. No heatsink. Monterey. I installed Macs Fan Control and it shows an average temp of 52-58C. When I use DiskSpeed test it goes up to 74C. Hopefully, it won't fry off.
Then you are safe! For normal usage and even I think for someone like me photo/video editing(not raw 8k video) is gonna be fine!
I just installed a 1TB Samsung 970 EVO PLUS (Phoenix version) in an iMac 27" 2017 and I am very disappointed with very slow boot time : 3 minutes.
APFS+Monterey+Samsung => Slow boot caused by trim
It is easy to see if you have the problem :
2021-12-20 19:52:24.163825+0100 0x74 Default 0x0 0 0 kernel: (apfs) spaceman_scan_free_blocks:3153: disk2 scan took 165.375232 s, trims took 165.092415 s
There is a bug with trim in Monterey and the only solution seems to use a WD Black SN750 instead of a Samsung NVMe.
Some information here :
https://forums.macrumors.com/thread...r-slow-boot-on-monterey.2310537/post-30531523
And more explanation here :
https://www.tonymacx86.com/threads/general-nvme-drive-problems-fatal.316546/
APFS+Monterey+Samsung => Slow boot caused by trim
It is easy to see if you have the problem :
log show --last boot | grep "trims took"2021-12-20 19:52:24.163825+0100 0x74 Default 0x0 0 0 kernel: (apfs) spaceman_scan_free_blocks:3153: disk2 scan took 165.375232 s, trims took 165.092415 s
There is a bug with trim in Monterey and the only solution seems to use a WD Black SN750 instead of a Samsung NVMe.
Some information here :
https://forums.macrumors.com/thread...r-slow-boot-on-monterey.2310537/post-30531523
And more explanation here :
https://www.tonymacx86.com/threads/general-nvme-drive-problems-fatal.316546/
Well me and many others here did the upgrade and we have around 3000mb read and write speed! Maybe you did not install the ssd good or your adapter is defected! I did instal fresh Monterey 12.0.1 and later updated to 12.1 which I got better performance! So maybe you have to do fresh OS or check your adapter or ssd that they in good in place!
Another thing could be if you are still using or have Fusion old HDD! Or your RAM is not enough or not the fastest!
Have samsung 970 2tb evo plus(old version) and long end which the C sintech adapter!(27" 5k late 2015 48gb OWC ram)! Trim was enable but default when I installed fresh Monterey OS!
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Read and write speed are not the problem : read around 2800 MB/s, write around 2500 MB/s then quickly goes down to 1500MB/s.
The trim problem appeared with Monterey so people who did the upgrade before could not see it.
Is your NVMe boot drive formatted APFS with Monterey ? If yes, then enter the command
Code:
log show --last boot | grep "trims took"Well These ssds have limited cash size! Which after few min speed test it will drop to 1500mb/s as you said which is normal! Dont thing they just keep same 3000mb/s speed all the time with heavy loads! The old version is slower which after cash gets full will drop the speed to around 1500 and new version of evo plus which is faster but later will drop speed to 800mb/s!
My ssd yes is APFS formatted! I have to check this command you gave... By the way my boot time is fast!
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It is just getting worse.Hi there,
any progress with the slow boot? It drives me crazy
2022-09-15 00:14:15.102098+0200 0x317 Default 0x0 0 0 kernel: (apfs) spaceman_scan_free_blocks:3154: disk2 scan took 233.066067 s, trims took 232.757002 s
