Problems after installing SSD as second drive.

Hey everybody,

first i want to say this i really a great forum. I've read many times in it. Unfortunately my first post here is because of a problem.

I've installed a Samsung 840 SSD to the second SATA-Port of my iMac along this tutorial: Installing iMac Intel 21.5" EMC 2428 Dual Hard Drive Kit. HDD is still on first SATA-Port, OpticalDrive is still on thirst SATA-Port. Then i've installed Mountain Lion on SSD and made it bootable. SSD and HDD work fine. But, after this modification i have problems with all USB-Devices, Firewire-Devices and the OpticalDrive. DataStreams break up constantly, so transfering data to external devices is very slow and jerky, also reading from DVD. Burning a DVD is really impossible because break of DataStream. Getting following error: Unable to burn. The disc drive didn't respond properly and can't recover or retry. Sometimes I also loose connection to USB-Devices. Everything worked fine with Lion and without SSD.

My first idea was, that the SSD slows down the USB-Controller but i have no idea why the OpticalDrive and Firewire are affected too. Maybe then the problem is the Bus between controllers and CPU/Ram? Does anybody know something about this problem?

 

Ok, ich have new findings

Firewire and USB seem to be ok. Did some tests and transfer-rates are high enough and near-constant. Exceptional case: Writing small files to an USB-Stick is very slow (less then 2 MB/s).

OpticalDrive also works but it performs very slow (dont know how is was before adding the SSD). It reads a DVD-R with 3x. Furthermore I was able to burn down a CD without errors. dont know why it has problems with burning a DVD.

One problem still exists: After updating to Mountain Lion i can not burn with my external USB Burning Drive anymore. Mac OS doesnt accept it as Burning-Drive.