Multiple hard drive sata cable pcb thing


#1

Somebody please let me know if theres something like this in existence. Or link me to a freelancer or company who can build it relatively inexpensive ( under 5k).


#2

Hey :smiley:

I thought about your idea again. So, what is the goal of adding a PCB with multiple SATA connections on it vs. using multiple SATA cables? Is it just for fun or does it provide some advantage?

Basically you’re looking for the PCB right?

I know somebody who is running a small consultancy in the USA that might be interested to do it. Once I know more, I’ll contact him and share the link, so he can check it out :slight_smile::rocket:


#3

Hi,
SATA does need twisted pair cables and also has to be shielded, SATA cables have each signal pair shielded whit a second shield over the 2 pairs. All those shields have a separate ground pin on the connector.

So i think you will get quite some signal integrity problems with this idea.

If it’s just for the cool look (and i have to say that it looks really cool in my opinion), just cheat a bit and use sata cables behind the PCB, if you cover all the connectors noone will see it :slight_smile:


#4

I definitely agree with you @Swiip it’s going to be a really tough signal integrity battle.

I think you won’t be able to have the traces on the top layer (visible). You’d have to move them in between two massive shielding layers. Definitely a 4-layer board or more.

I wouldn’t say it’s impossible. It’s just a really interesting signal integrity task :wink:. And it will probably require a lot of simulation and calculation to get it right.

Btw, at first I didn’t see the “XMETRIX DATABOARD V1” in the picture. Did you create this picture yourself @xmetrix?


#5

that could actually work :slight_smile: would be nice if “somebody” tried that.

grafik
I found some flexprint versions, but they are all really short.

grafik
Or flat ribbon cable with alu-tape on top :smiley: but also short.


#6

Nice!! So it seems possible. Only question is how reliably those work. Especially if we would put several in parallel :yum:

The length is definitely critical, so maybe if that’s possible it would be better to stack a couple of the HDs and maybe make 2 PCBs.


#7

Yes I created that rendering. The top layer would just be silkprint traces while all the acutal traces would be internal. I was thinking 6 layer board with multiple ground traces on the top and bottom 2 boards. all the data signals on the bottom of the third layer and top of the 4th layer. The reason i’ve never attempted it is because i realize it’s not as simple as laying out traces as the photo suggests. But… it cant be THAT terribly impossible with all the information and people on the internet available. If i could spend a few hundred on some prototypes to get one that works reliably enough to say hey i might be onto something here… then i’d dump more money into it but I’ve already figured a bare minimum entry into this project would be 5k. If i saw promise and hurdles were being overcome without too much headache and time invested I’d be willing to dump 10-50k into it; provided that I could easily take what was learned, augment, and release variants. Could be a sick start of a new openNas platform.


#8

Yeah, I think that sounds pretty good :smiley:. I also think it’s not impossible just something where you really have to keep control of signal integrity.

The initial person I thought might be able to help you is very busy at the moment. However, you could ask for a price from this freelancer: http://www.scalarelectronics.com He’s also based in the USA

But he will probably expect a little description and short specification sheet on what you are trying to do :wink:

Or you can wait until more people sign up and somebody comes along that would like to do it :smiley:. What kind of openNas platform did you have in mind? I mean is it just going to be the board or will there be more?


#9

First i would try a single SATA extension PCB with 50cm length, if this does work, it should also work with more devices on 1 board.

Do you also plan to use the PCB to deliver power to the HDD?


#10

In case you’d like to try to build it yourself. Here is a very easy to use (but still quite accurate) circuit calculator.
It can calculate what trace width and spacing you need to achieve a certain impedance. You’d have to research what impedance etc. SATA needs.

https://www.saturnpcb.com/pcb_toolkit.htm


#11

I found a nice document about High-Speed Interface Layout Guidelines