Once a game is loaded the SLI will help you more than the SSD drive if you are worried about frame rates. If you want a fast booting computer than go Raid 0.
I personally go the SLI route since your gaming. And transfering files off to your external HD will most likely be limited by the external HD even with 1 SSD by either the way it's connected if it's USB 2.0 or by the external HD speeds.
Ok so we can forget about the file transfers from the external. The Raid 0 will still help a lot on load times for games, boot up, and general programs. Is messing around with sli compatibility worth it over the ease of Raid 0?
Raid0 0 Will NOT improve OS load nor program load times as these are goverend by 4 K random performance and access time - of which raid0 does nothing for Nor will it improve FPS for games.
Raid0 will improve read/write of large Sequencial files on SSD into memory. Overall How much is difficault to say, primarily dependent on file size and frequency.
Being realistic, do encoding for large video files (.VOBs are 1 gig for a single file (4 to 6 per DVD, And Blue-ray is up to 6 gigs per one file. I have 16 gigs of ram and converting a .vob or blue ray to a 3 gig Meg file (for play back on tablet (or computer when on travel) Is Not effected by the read/write difference between SSD and Raid0 of SSD - It is CPU intensive. Ie it takes almost the same time to convert if file is on a SLOW HDD vs a fast SSD.
LONG time supporter of Raid0, However quit using with SSDs, and ALL my systems have daul SSDs except one laptop.
RetiredChief gave you good advice on raid-0.
With the advent of cheaper SSD's, I suggest you just replace the hard drive with a SSD of suitable size.
I have done this before on the same type lenovo laptops and it is not hard to do.
You will be pleased with the performance in everything you do.
The SSD will be 3x faster in sequential, so there will be a big advantage over raid-0.
^ "with a SSD of suitable size"
What Geofelt is getting at is that if instead of a pair of say 120/128 gig SSD you instead bought a single 240/256 gig SSD (Basically the same cost if not cheaper); You would probably see a better overall performance gain compared to raid0 with the smaller SSDs.
Reason is that the bigger "brother" (240/256 gig) has higher performance than it's smaller sibling (120/128 gig). That is for both 4 K random and Sequencial performance which interns negates the Raid0 only increasing large file sequencial performance using the 120/128 gig SSDs
Ok, you guys convinced me that Raid 0 is out. So is having to deal with getting 650m sli working with games worth dealing with over the 660m single? Battery doesn't matter and I have a good cooling pad.