M4400 or M6400 on the "same" configuration?

M4400:

Intel® Core™ 2 Extreme X9100 (3.06GHz,6MB L2 Cache, 1066MHz)
8GB, 800MHz DDR2 Dual Channel
512MB Discrete nVidia FX1700M Graphics Card (with 512MB dedicated memory)
15.4in Widescreen WUXGA (1920X1200) with 2CCFL

M6400:

Intel® Core™ 2 Extreme X9100 (3.06GHz,6MB L2 Cache, 1066MHz)
8GB, 1066MHz DDR3 SDRAM Memory(or 12GB)
1GB NVIDIA Quadro FX3700M (with 1GB dedicated memory)
17in WUXGA RGB LED Silver Edge To Edge Back-Lit Display (1920x1200)

is a marked difference in the performance of these two laptop Aside significant difference in the performance of graphics cards?

notebook I used for demanding machining simulation and verification(Vericut,Solidworks,Solidcam,Catia....special software for machining of turbine blades Turbosoft+)

 

If you get the M4400 i'd go for the FX770, the FX1700 will only raise the heat levels without giving much more performance. Especially with the CPU you have in it.
Besides heat the main differences are display size, The M6400 can carry 2 HDD's whereas with the M4400 you'll have to swap the DVD for a HDD caddy in the media bay. And you can use 4x2gb sticks to get 8gb RAM in the M6400 or upgrade4 to 16gb later on, M4400 only has 2 slots. And weight...the M6400is large and heavy.
I have no hands-on experience with the M6400 but i can say my M4400 has been very, very solid using 3dsmax. I don't know if your software does more "continuos" calculations with realtime simulation instead of just at rendertime but if so, you'd might want to look at a good notebook cooler if you go for the M4400 with that config.
Both will do a good job though.

 

I do have to say for that resolution screen, the 17" would be my preferred choice.

 

Yeah, WUXGA in 15-inch screens is very small indeed. If you're comfortable with that, the M4400 sounds like a good bet, it will be lighter and more portable.

 

15" WUXGA is small but that's a very personal choice. I have no problem with it whatsoever and i don't use scaling, zoom or anything like it on any program. Works fine for me!

 

really depends on if you mind the added size and weight of a 17", keep in mind the power brick for the m6400 weighs more and is the size of some small netbooks lol.

if size is not a big concern i'd go for the m6400 because its a bit more scalable than the m4400

 

M6400 all the way...there's also a slimline version of their power brick as well

 

M4400 I have a little less configuration...
Resolution 1920x1200 on 15.4 is very good for me.
Course, 17" would be better but not the main reason for a possible transition to M6400.

I had the opportunity to have a M4400 with the FX770 and FX1700.
level of heat comes to me on both very similar.

Since the M6400 we expect the lower level of the heating system and thus less risk downclock GPU but also CPU