SSD is really the ONLY way to video edit now. RAID arrays are dead, defunct, NADA now ! I have been using a SSD for 8 months now - there is no going back !
I has a custom laptop built up for me to my specs, based on the CLEVO P150 15" chassis:
512GB MICRON / CRUCIAL M4/C400 SSD
i7 2960 XM (has hyper threading - ie 8 virtual cores) (SANDYBRIDGE)
Gforce GTX580M GPU
16GB 1600MHz RAM - you will need all this ram for rendering previews
2x USB 3 ports
DVI monitor port & a separate HDMI port
anti glare matt screen 87% RGB gamut
Wifi & Blutooth
There are at least 20 custom lappy builders using this chassis. eg SAGER
Why all this horse power ? My work flow de-noises the clip in Adobe After Effects 5.5 or Premier Pro 5.5 using the NEAT VIDEO plugin and save to incompressed upscaled 32bit (huuuge) file prior to other effexts, eg STABILIZING. With my GPU over-clocked about 20% and on the verge of crashing, this denoising is about 7.5 fps, is still not exactly realtime. My friend has severly overclocked desktop i7960 and he manages 12 fps for the same denoising. I understand that the i7 3960 XM (IVY BRIDGE) is about 7% faster.
My lappy can render upto 7x simple PP or AE effects in real time ! - use the HDMI and watch it on my TV in real time.
A much cheaper option would be to buy the fastest Dell or Toshiba lappy you can, with a CUDA GPU (any GForce GPU with 1GB of RAM, ie the GTx 460 or better) and have a SSD installed by the supplier. I currently recommend the Samsung 512GB 830 Series Internal 2.5" Solid State Drive (SSD) http://www.bhphotovideo.com/c/product/845683-REG/Samsung_MZ_7PC512B_WW_512GB_SSD_830_SERIES_INTERNAL.html
- fast read and write. Beware that a regular lappy is not designed for continuous 100% loading, but the CLEVO based lappys are. The Alienware (DELL) are worth looking @ too.
Why an SSD ? your editing software reads, processes, then writes. With a mecanical HDD, the last thing you want to do is read and write to the same physical HDD (partitions mean nothing) - the heads vibrate like mad, and after a while there is no sound, and trust me, that is not good at all ! With a SSD, I read a and write to the same drive all the time - is fantasticaly liberating ! Group all you project files in the same place - makes life easy. And SSDs are lighter ina laptop, and only use about 5W max - ie, longer battery life.
Many laptops do not have a DVI monitor output, only HDMI. When video editing, I have a 30" Dell (calibrated & 100% RGB gamut) plugged in to the DVI - this lets me run the 1080p preview clip in a window without scaling, and my common tool bars areastill visible. I can also have my TV connected the HDMI to preview the clip on the TV - best of both worlds ! I definitly think 1x 30" monitor + TV is better than 2x 24" monitors.