I have a supermicro 5in3 on one side and a supermicro sas card on the other side. Both have cables that have one connector to attach to cabinet and card and 5 sata connectors on the other side of the cable.

 

I need to combine them but that would mean I need to connect two sata cables together.

 

Now I have found connectors rhat can do this but I would like a little "peer review" on that solution, is there a better way ? Such "connect two sata cables together" connectors" also look like a cause of issues in future, is there a better way ?

I think you want a different cable.  Sounds like you have a Breakout cable and a reverse Breakout.  Probably SFF 8087

 

You can get single cable to replace both.

Sorry, I did not explain clearly.

 

The 5in3 allready HAS a cable that spins out in 5 individual sata connectors

The SATA SAS card allready HAS a cable that spins out in 8 individual sata connectors

 

What cable should I use ?

I would suggest to purchase a cable that directly connects the 5in3 to the controller, and avoid any attempt at somehow connecting the SATA connectors of the two cables (I'm not even aware that such a thing is possible).

 

Which controller and 5in3 model are you talking about specifically? Can't be the 5in3 listed in your signature, because that one has 5 individual SATA connectors. If the controller is the SASLP-MV8, that side needs a SFF-8087 connector.

Its actually the 4in1, the Supermicro CSE-M14TB .. Any idea what cable to use ?  I do not like the idea of the connector so would like to avoid it.. On the other hand... Some of the 2,5" drives need to go to the motherboard, and some would need to go to the MV8 (this for esxi vt-d passthru)

The CSE-M14TB has a SFF-8484 socket, so you would need a SFF-8484 to SFF-8087 adapter cable to connect it directly to the SASLP-MV8.

 

But of course all the drives would be passed through then, and not only some of them.