SSUBX only running at x2 in x4 adapter.. HELP?

[zedex]

Hi there - I have an unusual situation..

I own 2 Samsung SSUBX SSDs - one is a 512GB model and the other is a 256GB model and both have identical part numbers.

I also have two 12+16 pin host PCIE adapters which are also identical.

The 512GB SSUBX was very recently acquired (2nd hand) and displays in Sys Info as [Link Width x2 at 5 GT/s] and despite exhaustive troubleshooting, I have not been able to get it to register in System Information as [Link Width x4 at 5 GT/s]

Here's the thing:
- the 256GB shows [Link Width x4 at 5 GT/s]
- the 512GB shows [Link Width x2 at 5 GT/s]
- I have swapped SSDs between Generic brand 12+16 pin host PCIE adapters and get same results (so it's not the 'low cost' adapter at fault)
- I have swapped the PCIe slot position for both SSDs in multiple configs (256G in Slot 3, 512G in Slot 4 / 256G in Slot 4, 512G in Slot 3 / 512G in Slot 4 ONLY and Slot 3 ONLY)
- I have tried lots of repositioning of disk in adapter and in PCIe slot for correct pins connection.

Has anyone come across an SSUBX which connects at x2 only (my research says they're all PCIe 3.0 x4)?
Is there something anomalous about SLOT 3 or SLOT 4 that means they won't both offer x4 connection concurrently?

Also - there maybe a better quality HBA to assist - please share the name of the [apple proprietary interface] 12+16 pin host PCIE adapter you use with your SSUBX (or SSUAX)
I'd love a solution to this puzzle - any answers appreciated

OTHER INFO
the pcie device is identical for both devices (conflict??)
bootrom version 140.00
tested in Yosemite and HS
[doublepost=1542542826][/doublepost]Another thought - could it have been 'set' (through firmware/software) to run at x2 it its previous device (iMac/MBP MBA)?

 

[crjackson2134]

I’ve had these before without any trouble like this.

I’m no expert on the subject, but it sounds like it’s either... Not an SSUBX (possibly counterfeit), or it’s defective.

Can you return it to the seller and get a different one?

EDIT:
I just noticed you are on Yosemite. Stick to High Sierra until you figure this out.

 

[zedex]

Thanks for weighing in crjackson2134 - I read through a healthy slice of the monster thread on PCIe adapters for the SSUBX. I might try buying a SINTECH adapter and see if that produces a different result.

Just a quick question - I came across your discovery of the [POST 833] CYCLONE PCIe2-437 Four Slot PCI Express Switched Riser Card - any idea of what this costs? and do you know if it contains the switch that allows you to use all 16 lanes in Slot 2 at once?

ALSO - Has anyone recommended a safe cleaning fluid that I could use to try and improve the pin connectivity between the SSUBX and my current adapter?

 

[crjackson2134]

ALSO - Has anyone recommended a safe cleaning fluid that I could use to try and improve the pin connectivity between the SSUBX and my current adapter?

Isopropyl Alcohol 90% and cotton swabs.

any idea of what this costs? and do you know if it contains the switch that allows you to use all 16 lanes in Slot 2 at once?

I have no idea what that card costs, I’ll look for one shortly. I don’t even recall posting about it.

A quick look at the marketing material, states specs and shows you can use upto 4x lanes for each slot simultaneously. This gives you full use of the native x16 host slot.

 

[zedex]

brilliant - thanks