Why do some users of Dell XPS 14Z get sata III and others only Sata II

There's no difference in the hardware - and assuming the BIOS level and drivers are the same, I'd bet on it being an incompatibility with different models of SSD - the SSD industry is still in its infancy and there are some models that just don't work well with some systems.

I don't know why Dell support wont help out with this, but this is what I have found. I have gone back to Bios A00 and removed and replaced drivers. As soon as I reboot and open Intel rapid storage technology program it shows sata transfer rate 6 GB. I run a benchmark and I see the 550 transfer rates. Shortly later I only see 3 GB transfer rate. Can anyone tell me why this is being shut down. And why when upgrading bios its 3gb only? Why is dell locking this feature out?

I have done some more research and have found that my laptop has the affected sandy bridge cougar chipset. That is most likely the problem I am having. My laptop is not one of the models that dell has admitted has the problem. But I have affirmed it is. I have done the cmd below and mine is an  rev 4...Now to get dell to admit it!!

It is here where you need to type the "wmic idecontroller get deviceid" command which will return the PCI ID of the chipset that contains the storage controller, unless additional IDE or SATA controller are installed.

The result should be something similar to the image on the left.

Although it looks rather cryptic at first sight, we are only interested in the revision number of the chipset, the “REV_xx” field.

If this reads “REV_04” as in the provided example, then your motherboard is based on the B2 revision of the Cougar Point chipset and is affected by the SATA 3Gbps bug, otherwise you are in the clear.

And the recall didn't affect notebooks - only desktops, because it doesn't show itself with just one or two SATA drives.

Ok so it did involve laptops, however I also read that it is indeed port 2-6, so why the heck am I not able to pull 6gb sata 3 speeds after a couple minutes use

Help. Anyone figure this out yet?

I too have REV_04.  I got my refurbished 14z last week.

I would like to say that I too have the same problem.  The Crucial M4 I first bought would be at SATA III for 5 days, then it would go down to SATA II and stayed there.  After Dell replaced the motherboard and CPU, it didn't go away.  So they told me my SSD may not be compatible or is defective.  I returned the Crucial and replaced it with a Samsung 830 128GB, the same brand Dell uses on their laptops.  The problem remains.   They finally decided to depot my laptop and it has been a week now and the tech still cannot resolve the issue.  Once I get my laptop back, I will update you on what they did or what they have decided to do.  Even though they were against my sending in the laptop with my Samsung 830 SSD bc I purchased it from a third party, I did it anyway to let them see the problem.  As of now, it is being delayed bc they said they need to wait for a replacement part.

Please let me know the outcome......This is really making me angry. Besides this my lan port is faulty and my fan is really load. This thing is falling apart

Just got my laptop back and did a check and mine is also REV_04.  Anyway, the only thing that the tech at depot did was replaced my motherboard like the tech that came to my house did once before.  Obviously it didn't work then, and it doesn't work now.  IRST is still showing 3Gb/s.  I am pretty sure he couldn't figure it out how to fix it so he just sends it back to me and let other Dell tech deal with it.  I'm going to contact Dell tech again and tell them that the problem hasn't been resolved.  I will inform them about Vlally's resarch on the SATA 3Gbps bug.

As for the fan, yeah, mine goes crazy when I first had my laptop, which I bought new, due to random overheating.  They fixed it with a new fan and motherboard replacement and that seemed to help.   Have not tried out the LAN port as I use wifi.  However, wifi is weak and would cut out randomly when I first had my laptop.  After a driver update, it seems a little better.  The signal strength may not be as strong as other Dell laptops, but it only lose one bar when I am two room away instead of two bar like before.  And complete signal drop doesn't happen as often.  I am pretty sure you are still under warranty so please notify Dell about your problem, as well as the SATA issue.  The more complaints there are, the more Dell will have to look into the problem.

I will continue to update the situation when I get new information from Dell tech.

Just finished chatting with Dell for 45 minutes.  I directed them to this forum and told them about what Vlally suggested about the SATA bug.  I don't know if they care or not but all they reply was "ok".  Finally, they said they will send me a replacemnt system and suggested that I send my SSD back to the retailer or manufacturer.  So basically, nothing is resolved, except I am getting either a new or refurbished laptop.  

I will try again with the replacement system when it comes and will let you know if anything changes.  If it is the same, then I think I am going to just give up because I am so tired of this.  I've been going back and forth with Dell for over a month already and nothing is resolved.  I hate having to sit at home and wait for Dell tech to come and for not having my laptop for over a week because it is in depot.  Dell would always replace the parts first, and if that doesn't work, blame it on the SSD.  

I am using my laptop casually anyway so for real world performance, it doesn't really make much of a difference if it is SATA II or SATA III.  I mainly use it for booting up Windows and Applications faster.  Currently, it boots up in 13-14 sec which is okay with me.  When I had SATA III, it was booting up in 11-12sec.  Yeah, I am upset that I can't use my SSD's full potential, but I am just too tired to deal with DELL just so I can get 1 or 2 second back for every boot up.  If you are doing a lot of hardcore applications that requires a lot of reading and writing off of your SSD, then please go and complain with Dell so that I may benefit from it if anything is to be done.  As of now, I am withdrawing from this fight. =/

Just received a new 14z replacement from Dell.  Clone the HDD to the SSD and the SATA connection is still at 3 Gb/s.  Did a clean Windows 7 install and it is also still at 3 Gb/s.  I am beginning to think that it might be the Intel chip problem.  If so, then this won't be fixed any time soon.  If it is a hardware problem, then it probably won't be fixed unless Dell does a recall and Intel replace the chip.  Not likely because it is too unfeasible for both company.  If it is a sofware problem, then hopefully Intel or Dell can send out a patch or an update soon.  As of now, I think I will just take my SATA II connection and live with it because it doesn't make much of a difference for my boot time.  I can live with 1 second slower. Please keep me updated if any of you have enough good news.

I did this command on my XPS 15z and it has REV_05 on it!

It running in SATA 3.

Is that the reason why?

Can Dell do anything?

Dell tech just called me today to check on my replacement.  I have informed him that the problem still exists with the SSD.  He said that Dell is aware of the situation as other people besides me have contacted them about it.  He said that Dell will try to fix it through a BIOS update once they can figure out a solution.  Will they do it and when, I don't know.  I am just glad that enough people have complained to Dell that they are looking into the issue.

I am really dissapointed in Dell. I paid good money for this laptop and besides it haveing a hardware issue that wont allow the full sata 3 support. This thing is slowly falling apart. My lan port is fully dead, even after clean install, the fan is loud and very unstable. This thing heats up like an oven. Dell has agreed to replace the fan and motherboard, but I have not been able to make this happen as I travel 95% of the time and they will only schedule my home address. I fear that this laptop is going to fully die on me while Im on the road and be SOL. There was a time I thought Dell was an inferior product, but I believe a made the wrong choice going with dell this time. They are well aware of the problems of this machine but continue to sale it even though so many people have had the same problems. They waste time and money replaceing motherboards, when they know it wont fix a thing. My business partner has this same model and has nothing but problems as well. I can assure you one thing......I will never buy from Dell again, as they cant even step up to the plate and 1) admit the problem 2)rectify the problem or offer replacement product that does work the way it was suppose to. I like the size of my 14z, but give us the option of the 14z that will run sata 3 and doesnt have all the other problems people are running into. Come on Dell stand by your product and stop wasting our time by making us spend countless hours on the phone with tech support, who acts clueless about all the problems so many of us face.