I've spent literally hours reading posts about the Marvell 9128 controller. Some of you have been very helpful in answering dozens of posts on the subject.
But there's still something I don't get. Given that everything I've read about it is negative (I've not seen a single positive comment) : Why is it there ?
Why does ASUS, for exemple, install the thing on their high-end boards ? Is it good for anything ? Everybody recommends disabling it in the bios and using the Intel ports. Couldn't ASUS and others install something better that might actually get used ?
IMO it’s there as a cheap way to give SATA revision 3.0 speeds.
Technically, SATA 3.0 speeds are from 301MB/s to 600MB/s.
The only thing I think it’s really good for is to give "greater-than-SATA 2.0" performance to SATA 3.0 SSDs.
But it doesn't even do that. Maybe with a single SSD it'll provide slightly faster performance than a SATA 2.0 port, but not with two if I've read things correctly. So why offer two ports off the controller ?
There are also all sorts of complications and things that can go wrong when someone actually tries to use the thing. An example of strangeness : the manual for the current ASUS P9X79 WS motherboard (which I would hope is a good example of the high end) has this to say for installing RAID drivers for the controller :
"A floppy disk with the RAID driver is required when installing a Windows® operating system on a hard disk drive that is included in a RAID set."
Who has a floppy disk drive these days ? They're ancient history and this board is supposed to be modern ?
Then there's an issue of false advertising that either misleads the uninformed or confuses those trying to understand. Using ASUS again as an exemple (they're in no way alone), they proclaim two additional SATA 3 ports. Period. They don't mention that both these ports go through a single PCIe lane and that if you use both (what a strange idea) you'll get no better than SATA 2, if that. Makes you wonder about the other claims manufacturers are making. You have to spend weeks of study just to figure out if what a manufacturer says is true or not, and still not really be sure until you've bought the product and can see for yourself.
Thank god for these forums and others. Without them I'd be completely lost.
Probably the biggest reason is to add more sata ports, even if they are "poor" sata III choice.
The only use that I have for them is Running a HDD off of as a HDD is not going to saturate a sata II port. Only advantage of SATA III HDD on Sata III port is Burst speed - Biggy, NOT.
Case in point, My SB system (Azrock Extreme 4), I have two DVD drives (ones a Blu-ray writer), 2 HDDs, and two SATA III SSDs. That maxes out the Intel sata III/II ports. No choice if want to add a 3rd HDD but to use the Marvel Controller.
PS. On Newer systems you can place the "F6" driver on a USB thumbdrive instead of a Floppy Disk - So Do not need a FDD to install additional drivers required for windows install.