http://www.tomshardware.com/reviews/gtx-580m-sli-hd-6990m-crossfire,3022.html That's pretty much everything you'll need to know. Alienware laptops are nice but they are expensive as hell. You might want to look at the Eurocom Panther 2.0 if you need the fastest Laptop ever. If the SLI GTX 580M costs a lot more than the AMD 6990M then go with AMD. On Alienware they are charging $700 extra for the GTX 580M SLI.
$7038
I could build you even more power using a Shuttle for half the price, finally you always pay big in order to go small. Funnily enough, huge towers cost even lesser than the Shuttle for even more power, so i truly wonder where they get all the material for free.
Apparently the manufacturing is eating it all, which is surely not the full truth.
Alienware M18X
2920XM 4.2ghz
Crossfire Radeon 6990M 4gb
Kingston HyperX 8gb 1600mhz
Crucial M4 256gb SSD + 750gb HDD
Surely very impressive to put such crazy stuff inside a laptop, although in practical means, as usual, it cost a lot to go small and i dont need a travel-portable device. Considering my SFF is already portable enough (easy to move from one location to another but not usable while traveling) and i just had to pay like 1/2 for equal power. Well yeah, everyone got theyr needs or joy.
Extra stuff you don't need.
OCing the memory depends on the BIOS and the strength of the CPU memory controller. IMO your best option is the top Sager with the dual 6990 option. They shove a high end desktop CPU in there, it will murder any mobile CPU.
1. OCing depends on the general quality of the board at first, the memory controllers usualy handle 1600 MHZ easy.
Its useless to go above 1600 MHZ, seriously. It doesnt match with the CPUs interface and only generate extremely minor speed up, if any at all.
2. The 990X is in my opinion misplaced in a laptop, its 130 (!!!) Watt TDP. Only Shuttle or mid/big towers can stay in the green range having it. On a Shuttle (probably the smallest system able to use the full 990X power) you might be able to put in a 5-10% OC without having the CPU burned (although the machine may get loud because it need to speed up fan). So its not possible to beat any machine bigger than that. So the best option is to get a low power CPU like 2920XM (+1 point for V10Ace) and on laptop that CPU is barely weaker, unless at a few special tasks. On bigger systems with some OC the 990X might be stronger but on laptop thats not possible, to much heat. And believe me there is lot of tears when a 990X will break or throttle because of heat! Usualy the 990X will protect itself by throttling down, and that most likely will happen on a laptop under full load. Then you will experience slower performance and that is just not advisable.
3. 6990M crossfire? Well i dont know how much they perform but usualy in laptops all processors share the same heat sink (unlike Shuttle who got dedicated sinks), those will have to be cooled down aswell and even CF, i surely feel impressed if any laptop truly can deal with at full clock and load. Combined with 990X it surely is over the edge, that pretty CPUs potential might be plagued by to much heat. So my vote would go to Alienware here. Indeed there might be other systems with same power for lower price. Question is of they are aswell build with the same quality considering theyr boards and case, thats something which have to be considered. Finally a CPU, especially on a laptop, is exactly as strong such as its cooling power, according to that the parts can deliver more or lesser...
