So a PCI slot is not used up in the process?

Nope (up to four drives).

Can I assume that same is true for XPS 400?

Thanks...........markojo

Yes.

Intel 945P Chipset, Intel Matrix Raid.

http://www.intel.com/design/chipsets/matrixstorage_sb.htm

My new XPS600 hasn't arrived yet but I was led to believe that XPS 600 uses the Nvidia Nforce4 16x SLI motherboard which includes their MediaShield storage solution for RAID.

Yes. XPS 600 has nVidia nForce chipset w. onboard Raid as well.

Is the XPS plagued with high noise fan issues as well ?

The XPS 600 stock fans are very quiet. My computer is (now) almost silent.

There is an issue with vibration though, for a few, that can make the computer VERY loud, usually with a pitch that raises and lowers ...

(waaaaaaaaa...WAAAAAAAAAAA...waaaaaaaa...WAAAAAAAAAA)

The vibration seems to be caused by the green plastic shroud over the CPU heatsink (which has the two CPU fans mounted to it) and the noise may come from the plastic grill on the back of the PC (which is simply cosmetic and can be removed). Some can stop the noise by opening the case and making sure the shroud is snapped in properly (just remove and reinstall it) or by gently bending the plastic of the shroud to make sure it doesn't touch the heat sink extensions (both worked for me); other's by removing the plastic grill on back of the case, some by wedging toothpicks between the parts that seemed to be causing the noise and the metal frame of the case...

Basically, if you are unlucky enough to experience the noise issue, you may be able to locate the source of the noise yourself and fix it at home (this may involve opening the case which does not effect your warranty at all).

Many were sent replacement fans, shroud assemblies, motherboards, powersupplies... almost anything by Dell to fix the issue. Usually new parts did not help. Some people have yet to fix their noise issue. It might depend on how ingenious you are.

The XPS designers admitted it was a design issue during the Live Chat and said they had a new part for it (which invloves new washer/gasket things on the CPU fan mounting). Haven't heard from anyone that has had success with the new part yet - but most folks tend to stop posting when they have no more problems.

Thanks CT skydiver!