m90 performance with RAID array?

Hey guys,
I am pretty close to purchasing an m90 as a replacement for my very high end desktop, because I love the capabilites and the portability of the machine but I have one concern: storage limitations. The m90 only has one internal SATA port with a maximum factory HD size of 120GB. But I would like closer to 1-2TB of high speed storage for working with uncompressed HD video (and gaming ). Obviously right now, it is impossible to get 2TB in a single internal 2.5" drive, so I decided on something like this: http://www.pc-pitstop.com/sata_cages...ures/a4in3.asp

It's a 4 drive SATA RAID array enclosure. I plan on having 4 500GB SATAII drives in it. Since the m90 does not have any eSATA ports, I figured I would have to get a D/Dock and a SATA controller PCI card. But I have serious reservations about the performance of this set up. The Latitude D/Dock is relatively old, as it was released with the D600 and I am concerned it cannot keep up with the bandwidth needs that I have. But then I saw that there are 2 different versions, a latitude version and an m90 version. Does anyone know if the m90 version is an updated one? More specifically, is the PCI slot a PCI Express slot and does it maybe offer any SATA ports?

As I mentioned above, I can get a 4 port SATA PCI Card and install it in the D/Dock. But where will this put me performance wise? SATAII has a transfer rate of 3Gb/s. A standard PCI slot is limited to 266MB/s When you combine this with the fact that a RAID array striped across 4 disks SHOULD approach 12Gb/s(obviously, in practice this will be substantially less due to bottlenecks in the chipset), this means a substantial bandwidth loss since I am limited to a single PCI slot's bandwidth(i would get a max of 266MB/s as opposed to 12GB/s - almost a 6000% loss of performance!!!)

Does anyone have a solution that would allow me to use a SATA or SAS RAID array at its full speed and capability? Right now, storage space is the only negative aspect of this machine and if I can get storage space, this would be the absolute perfect laptop.

thanks Vcdechagn, I didnt know the m90 had card slots. I'm not too familiar with Expresscard technology, is it supposed to be the laptop's version of PCI-E slots on a desktop? What type of PCI-E slot is it? (x1, x4, x16?) I know they make SAS PCI-E cards. If I could get a SAS Expresscard and connect some 10,000RPM SAS drives, that would be .

Yea, those enclosures are pretty cool. They have some really nice ones that include hot-swap trays and each tray has an LCD screen with a readout of some measurements of the drive (temp, voltage, etc). You can get them with SAS cables so you basically only need 1 cable to connect to your PC (a single SAS cable can carry data for 4 SATA drives) and help to reduce clutter.

the expresscard is the mobile version of the pci-e slot. PCI-e is limited to 1.5Gb/s per channel(I believe. and a single slot can have up to 16 channels...aka x16). Conventional PCI is limited to 266MB/s. Also, you can buy SATA enclosures with their own power supplies, no need to do any wiring yourself. I want a 5 drive enclosure so I can have over 2TB of storage. As far as speed, no hard drives currently on the market can actually utilize all 1.5GB/s of a SATA I connection, yet alone all 3Gb/s using SATAII. But, by using a SATAII card that supports port multipliers, I can have all 5 drives using a single SATA cable to connect my enclosure without any degredation in speed or perfromance. But it would be nice to just be able to use a PCI card in the D/Dock and not have to have a card sticking out the side of my machine.