Which CPU to choose?

I use my computer with the following purposes:

1. Scientific computation with Intel Visual Fortran 11.0 (windows)
2. Play some games, such as Warcraft and some older games
3. Use some P2P tools such as ppstream or pplive for online videos

I am not a DIY fan (I did some work such as RAM expansion, installation of new hard drive, DVD-RW ROM etc). So generally, I consider to buy from the vendors direclty

1. HP C2D E8400
(3G RAM, Intel Q963 Chipset, Nvidia Quadro 295)

2. HP e9105Z

AMD Phenom 9650 or Phenom II X4 920

3. HP e9110t

C2Q Q9400 or even e9150t i-7.


I might play game or do some video work while executing the computation. Possibly, the first one can handle it. However, it is also my concerns, the win7 is out pretty soon and the current configuration could be difficult for expansion or difficult to handle similar work compared to WinXP?

My budget is flexible. However, I also do not want to waste money on unnecessary configurations .

Thanks for your comments and advice.


(With concern of software compatibility, I might continue with 32bit)

All the processors should be 64 bit with VT technology for Windows XP virtualization in Win7. I'd make sure that the systems specifically say they support VT tech since many Mobos do not. Since you are running Fortran code I'm guessing you are running some awful other old DOS based scientific software, this might be handy. It's not a requirement to run Win7 but it's good to have.

The i7 is future proof, but as said will lose against the E8400 in a single thread processing race. Just make sure the machine has discrete graphics (or buy it separately mindful of the power supply restrictions.)

I'd also consider getting two systems maybe a number cruncher and a cheap laptop/desktop with discrete graphics. I wouldn't want to be doing both game and run simulations on the same machine.