Second SATA Port Imac Mod

[SloMoJoe]

Hello all... I was inspired by the possibility of using two 2.5" drives - an SSD for booting and a larger magnetic drive for data in my Imac. As you probably know, there is space for one 3.5" drive in the Imac and one SATA port. However, at least in my late 2008 Intel Imac, the southbridge is an Intel ICH8M (located on the non-visible side of the motherboard right underneath the Airport card). This chip actually has three SATA connections on it, and the mobo only uses SATA0. Well it so happens that the connections for SATA1 and SATA2 seem to come through the PCB as exposed via's, potentially allowing connection to a cable.

 

So...I tried to do this. I took an unused SATA cable and snipped the connector off one end, routed it through the enclosure, hot-glued the end down next to the southbridge, and soldered the ends of the wires to some tiny coupling capacitors (as is needed for a SATA connection) and soldered some small jumper wires from those to the appropriate places on the logic board. Well...it didn't work. I tried connecting my original drive to the new cable and it would not boot; just got the "?" folder.

 

So here is where I come to you for advice. Admitting the possibility that my work was extraordinarily ugly and therefore impossible to perform at spec, I am also wondering if OSX is designed not to use any more than one SATA port with the ICH8. If so, could I borrow any tricks from the osx86 community and their KEXTs that enable all the SATA ports on various chipsets? Any help would be most appreciated. I have some pics, but I left my camera in the shop where I was working, so I'll post those as soon I can get it.

[bonestonne]

Considering that G5's and Mac Pro's have space for 2 or 4 drives respectively, OS X can definitely use more than one drive at a time.

 

Alternatively, what you did probably wasn't making enough contact. What you need to do is actually solder the cable into the main logic board. If done backwards, this could damage the board or the drive permanently, or it could do nothing, I can't say I've ever plugged a SATA drive in backwards ever.

 

At the same time, there are plenty of standard PC motherboards which appear to have the places for SATA ports, but the ports are not actually there. The ports can't actually be added, because the resources that could be dedicated to that port are either dedicated to something else, or non-existent on the board, most companies have a "reference model" which they pick and choose features, and create price ranges across the board while saving money by not including features on one vs the other.

 

In short, it probably wont work, but if you want to try, hot glue wont get you anywhere, you need to use a soldering iron.

[Manu0600]

I don't know if the iMac sata controller accepts more than one device. Apple do their own motherboard with their own controllers, maybe it can't handle 2 HDD (even if you add a second sata port by soldering).

The software (Mac OS X) accepts of course multiple HDD, but the controller doesn't take part of the OS.

 

Try to use the sata port of the CD/DVD drive, to test if the second HDD is accepted.

[SloMoJoe]

In short, it probably wont work, but if you want to try, hot glue wont get you anywhere, you need to use a soldering iron.

 

Hahaha. Well....I agree that hot glue won't make a connection. I soldered these connections, and tried both SATA1 and SATA2, but still no luck. I'll get the pics in here soon so exactly what I did makes sense. I appreciate your help and tips though.

[SloMoJoe]

OK, here are some pics of my failed attempt at this mod...mostly just for reference in case some body figures out how to make this work (...and for you entertainment.) I apologize for the very poor quality. I was using an ancient camera and I whipped up the labels on Paint.

 

Here is the view of the vias coming from the ICH8 BGA on the other side. The green boxes are basically the boundaries for the working pins (minus the power and ground in the middle).

 

Here is a closer view of the SATA connections. Port 0 is connected to the mobo SATA connector through coupling capacitors (I think).

 

This is a bird's eye view of the intended cable routing around the HD.

 

My first attempt was to connect the coupling capacitors (4 nF) end-up to the vias of SATA port 2 and connect the wires onto the end of those. Here are the caps soldered on the board.

 

Here they are connected.

 

Here is how the cable was routed. Unfortunately the LCD sits SO close to everything that the cable wouldn't allow it to seat properly, but I left it and gave it a test run. FAIL.

 

Not only did it not work, but there was too much tension on the capacitors and with a little movement the broke. Try 2. I rerouted the cable to stay out of the way of the LCD and decided to attempt connection to SATA port 1 after reading this post: http://www.insanelymac.com/forum/index.php?showtopic=48315

 

I also decided to solder small wires (single strands from multi-stranded wire) to the vias and connect those to the caps soldered on the ends of the SATA cable, in order to relieve the mechanical tension on the caps.

 

So this didn't work either. I removed everything, cleaned up the board, and put my computer back together. And yes....it still works (for you doubters). I would love to make this work someday if anyone can figure out where the issue is.

 

Some notes: The ground wires from the SATA cable were tied together and soldered to one of the ground planes on the board a couple inches away from the SATA connections. Here is the ICH8 datasheet: http://www.intel.com/assets/pdf/datasheet/313056.pdf