I was going to go with the P7P55D-E but then saw the P7P55D-E LX which is +-20€ less (in my country)
i will be putting an i5 750 and 4GB DDR3 with a Prolimatech Megahalems Rev. B CPU Cooler
the only thing i know is the PCI-E @4x is useless and not worth the 20€.
I will also loose:
1 x IEEE 1394a
1 x SATA 3Gb/s
i will still have 6 SATA 3Gb/s and no need for the IEEE 1394a.
under Precision Tweaker 2, there seems to be some different values.
will i loose any overclocking power by going with the LX version?
is the P7P55D-E worth the extra 20€?
i do have the Asus P7P55D-E LX, i prefer a board without multi-GPU slots, why? because i think it's not worth spending 2 times for the same video card for less than half the performance boost.
So i took the single PCIe 2.0 16x slot version, which also gave me more room for PCI cards and cooling like my X-Fi XtremeGamer PCI sound card.
It's a lot better to have 1 video card worth it than 2 of them. I use a Geforce GTS 250 512mb and it seem to run fine on this build (just DON'T buy OCZ memory, they really suck. I asked the online store to send me some G.Skill F3-12800CL7D-4GBRM instead, hopefully this will fix the problem i had with the previous RAM...
Also, if you have a 500W power supply, you're better with the LX version, since i won't even risk myself is running 2 x Geforce GTS 250 on that kind of power supply, and make sure it's a good brand that delivers the advertized power (for example, Seasonic and Corsair are 2 of the greatest brands, and the Enermax Modu82+ is an excellent power supply also.
So yes...SLi is not for me, and i would spend the money saved from the LX version for a good Noctua fan instead, no SLi, but better cooling.
Great choice of CPU cooling by the way, one of the best on the market right now. I do have the Megahalems rev.B on my Core i5 750 and Speedfan seem to give me outstanding coolings on idle on all cores, around 22 Celcius to 26 Celcius. I don't know if it's a diode reading error, but it seem to be extremely effective!
I use the Antec Three Hundred with a Nexus 120mm black-white on the Megahalems, a Noctua NF-S12B FLX at full speed for the back exhaust and a Noctua NF-P14 FLX at full speed for the top exhaust. Very effective and cheap-priced case, you also have access on the back of the board to install the CPU cooler's back plate! (on the newer revisions of the case that is, which have a "SSD compatible" advertizement on the box).