T420s Nvidia Graphics Card & Express Card Questions

Question

Hello, and thank you for checking out my post.  My apologies for writing a book, but I'm hoping to give as much detail as needed the first go round.
I just received my custom-built T420s (4170-CTO) and have a couple technical questions/concerns about it.  The details of my configuration are located at the bottom of this post.
First off, one of the deciding factors of my purchase was the discrete graphics card.  On the T420s I chose NVIDIA NVS 4200M Optimus Graphics 1GB, Intel Core i7-2620M Processor.  I was thrilled to have more than 256 MB of dedicated graphics memory for my games.  Upon receiving my laptop, though, I ran the Windows Experience Index and saw that the lowest score was the graphics card, which is identified as Intel HD Graphics Family and has 64 MB of dedicated graphics memory.  After my heart started beating again I checked Device Manager and found under Display both Intel HD Graphics Family and NVIDIA NVS 4200M listed as working with up-to-date drivers.  When I configured the laptop online there was no mention of hybrid graphics, so I'm not sure why I have an Intel Graphics card on the machine.  My current laptop that I was looking to replace is a T61p with a NVIDIA Quadro FX 570M graphics card, and only that NVIDIA card is shown under Device Manager and in the Windows Experience / Performance Information.  Thinking that perhaps disabling the Intel card would cause the NVIDIA card to take over, I disabled that through Device Manager.  My screen went black and after feeling quite stupid I rebooted my computer.  The default Windows Display driver kicked in, allowing me to see well enough to get back to Device Manager and enable the Intel Graphics.  I counted myself lucky that I wasn't stuck with a working computer with a blank screen, but I'm still confused about why the NVIDIA card isn't the only display adapter on the machine, and why it isn't the default/main adapter.  Most importantly, will it be usable to run my games?
My second question is regarding the PCI ExpressCard slot.  My aim for this machine was to have a HDD to store my data (I selected the 320GB 7200 RPM HDD) and a SSD to boot and run my programs from.  Another reason for choosing this machine was the comment on Lenovo's site stating that a user booted his T420s from a solid state drive in the PCI ExpressCard slot, which was exactly was I was looking for.  I need the CD/DVD drive, so I can't put the second hard drive in a caddy.  During configuration I chose the option for an Express Card Slot & 4 in 1 Card Reader & Smart Card Reader.  From what I can tell, the Express Card slot is not connected to the Card Readers and I will not lose use of those ports.  When I opened the computer up to install more RAM, I saw what is labeled in Lenovo's hardware manual as the Express Card slot, apparently empty - which is great!  Now I need to figure out what kind of SSD to look for, and on that I'm kinda lost.
I'm guessing that my ExpressCard slot is 34mm and PCI form factor rather than USB... but I don't want to spend hundreds of dollars on a not-incredibly-educated guess.  I'm also not sure where mSATA comes into play for me, if at all.  Looking at SSDs on sites such as newegg.com, I'm unsure of what form factor to choose - ExpressCard, PCI-E, mSATA, and/or 1.8"?
The tech specs of my configured T420s (copy/pasted from the order status) are as follows.  I hope this means more to you than it does to me.
Part #:
0A71709   VBB INTCRI7-2620MPR(2.7GHZ
45M3092   VBB GENWIN7HOMEPREM64    (which ultimately doesn't matter as I'll be booting from Windows 7 Enterprise on my SSD)
0A68718   SBB GW7 HP64 US ENGLISH
0A68976   SBB 14HD+LDBCKLTANTGLDSPMBBBRD
0A68972   SBB NVD12PNS2OPG1GBICI7-2620MP
45M4569   VBB 2GBPC3-10600DDR3 1333SODMM    (which has been removed and replaced by two 4GB sticks)
0A68978   SBB FINGERPRINT READER
0A68993   SBB 720P HD CAM+INTGR MCRPH
0A68990   SBB 320GB HRD DSK DRVE,7200RPM    (will be used for storage and as a backup boot device)
0A68985   SBB DVD RCRDBL8XMXDLLRULTRBSLM
0A68996   SBB EXCRSLOT+4IN1CRDRD+STCRDRD
0A68261   SBB BLUETOOTH 3.0
45M4805   SBB IN.CENTADV.-N+WIMAX 6250
44C7950   SBB INT WRLSSWDAREANTWRK UPGR
In Device Manager I see the following related (I think) devices located under System Device:
Intel 6 Series / C200 Series Chipset Family PCI Express Root Ports 2 (1C12), 4 (1C16), 5 (1C18), and 1 (1C10)
Intel 6 Series / C200 Series Chipset Family SMBus Controller 1C22
Intel QM67 Express Chipset Family LPC Interface Controller - 1C4F
PCI bus
2nd generation Intel Core processor family DRAM Controller - 0104
2nd generation Intel Core processor family PCI Express Conroller - 0101
Whew.  Thanks for making it through my book-long post.  If you can offer advice on either of my questions/concerns I'd really appreciate it.
Thanks!
Lauren

Answer 1

The T420s with Nvidia GPU has two graphics card that can switch on the fly, if you only want the discrete gpu, just go into your bios menu under graphics there is an option to select discrete.
With the Nvidia Optimus (which is what you have), it can switch between Nvidia and Intel GPU depending on your application needs. This will allow you to conserve battery or power.
Expresscard slot 34 mm slot is occupied by the card reader that you ordered.
What you are talking about within the ram slot cover, is the mPCIe slot, which can be occupied by a mSATA drive.
http://forum.lenovo.com/t5/T400-T500-and-newer-T-s​eries/T420s-T400s-T410s-removal-of-4-in-1-SD-card-​...
Regards,
Jin Li
May this year, be the year of 'DO'!
I am a volunteer, and not a paid staff of Lenovo or Microsoft