Samsung PM983 vs PM983a

erik_v

New Member
May 8, 2022
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Hi guys,

Hoping someone can help me with the difference of the above two units?
Seeing a lot of both on ebay at fairly attractive prices but I cannot seem to locate a spec sheet for the "a" version anywhere.

Given some of their other models I assume that it is an updated version with slightly better specs and hopefully still with PLP but I would like some more certainty.

For some surrounding color on this I am hoping to setup a 3 node distributed storage lab and would be hoping to use fast m.2 drives for write-caching type functionality. (Right now I think likely will be first trying GlusterFS over XFS in a few configurations. I am tempted to see about layering on ZFS but I think that is not "so" supported.)
 
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VMman

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Jun 26, 2013
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Hi, I have a few of the 1.8 TB ones on order.

I can share some detail once they arrive but this is what I can find online.

It appears these are made for OEM perhaps AWS or otherwise, they are under provisioned 900gb and 1.8tb vs the 960gb / 1.92tb of their retail counterparts which is likely done to enhance endurance and provide a more stable write speed.

I don't think there are any hardware changes like the removal of PLP from the photos I can see the CAPs visible.
PM983A Tested
 

erik_v

New Member
May 8, 2022
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Ah nice one thanks for that @VMman!

I had been about to post an update myself saying I wasn't sure that they were correct: I was thinking they were just mislabellings (and many may still be just that) as pulling P/Ns from a few pics just lead straight back to the PM983s
 

DarkServant

New Member
Apr 5, 2022
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Hi,
What i have seen on pictures of the pm983a is primary the change from gen.4 64-layer to gen.5 92-layer TLC V-NAND. On the m.2 22110 drives are more capacitors visible too.
I dont know if they are "hard-firmware" overprovisioned or with namespaces. The overprovisioning via namespace can be done yourself with the tool nvme-cli, likewise setting it to 4K sectorsize (4Kn), but take into account that the LBA size changes too with 4K.

Setting OP: NVMe® Namespaces
Set 4Kn: Switching your NVME ssd to 4k - Bjonnh.net
 

VMman

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Jun 26, 2013
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** Update **

These units run hot during benchmarks and high write workloads.

I found 98c in a 1U chassis with the fans turned up, I think a M2 heatsink would be recommended.
 

Glock24

Active Member
May 13, 2019
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Hi guys,

Hoping someone can help me with the difference of the above two units?
Seeing a lot of both on ebay at fairly attractive prices but I cannot seem to locate a spec sheet for the "a" version anywhere.

Given some of their other models I assume that it is an updated version with slightly better specs and hopefully still with PLP but I would like some more certainty.

For some surrounding color on this I am hoping to setup a 3 node distributed storage lab and would be hoping to use fast m.2 drives for write-caching type functionality. (Right now I think likely will be first trying GlusterFS over XFS in a few configurations. I am tempted to see about layering on ZFS but I think that is not "so" supported.)
A few days ago I was looking for ~2TB SSDs and saw good deals on those and wondered the same about specs.

How's power consumption and temps, anyone knows?
 

DarkServant

New Member
Apr 5, 2022
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Power envelope should be not higher than the non "a" version with 2,5watts idle ~8watts active on m.2 which is btw. a lot for this surface area.
For the u.2 its 4watts idle, active 10,6watts.
Possibly it's an issue with thermal throttling, or it is disabled on purpose? At around 100ºC thermal self-protection shutdown should kick in.

If possible i would take the U.2 versions, they allow way better options for cooling IMHO.
The first NVMe SSD i installed was an pm9a3, and i placed some thermal pads on the backside, on the controller and NAND chips (sandwich-style), then i put it in a 3,5 mounting/cooling frame from the old 10k rpm WD Velociraptor HDD (wd3000glfs)... Temperature stays mostly below 40ºC.
I think the pm983(a) has less thermal pads which not covering NAND and especially the PMIC.



PS: use soft to very soft compressible pad for the pmic and the other ones in the right thickness (better dont use those bone-hard 17+W/mK pads)

pm9a3-u2.jpg pm983-u2.jpg
 
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