What's your budget and what country at you in?

i am in scotland and my budget is about 1300 pounds

At 2.8GHz? I don't think so. CPU core clock speed is probably the single biggest performance factor when running MSFS. And the PMDG 744 is one of the most (if not THE most) CPU-intensive add-ons made for FSX.As to risk of overclocking...as long as you keep the core temps below 80 deg C, you're not going to hurt anything. Most of the OEM machines (but not all) have the clock speeds locked in the BIOS and can't be overclocked. AFAIK all of Alienware's machines can be. Moderate overclocks are really easy to do, especially if the machine was built with that in mind, as Alienware does.Anyway, I don't think a 2.8GHz quad is going to give you the FSX performance you seek. To get there, you'll need to be in the mid-upper 3GHz range on the CPU...and preferably with a bit more powerful GPU than a 260 as well (at ~$200 the new GTX460 looks like a good way to go). You can do that easily and cheaply with a moderate overclock, or expensively with a faster rated CPU.RegardBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Right so would these specs be acceptable for the performance i want:PROCESSOR:Intel® Core™ i7 Processor 880 (3.06GHz, 8MB)MEMORY:8192MB (4x2GB) 1333MHz DDR3 Dual Channel MemoryGRAPHICS CARD: Single 1.8GB Nvidia GeForce GTX 260dell dont seem to offer a better graphics card but i can get a better processor

I'm glad I kept this laptop in my bookmarks: ASUS G73Jh

And you want a laptop or desktop? I'm from Scotland also, where about are you?

i dont mind both will work and i am in glasgow

What's your budget and what country at you in?

besides i7 processors have a turbo boost and i beleive this one boosts up to 3.33ghz

Laptop: alienware m15x hands down. Best cooling and can be OCd.Desktop: Alienware, or build your own. Dell desktops are tbh crap. They have locked bios's and all the parts are cheap quality.

but which would win on performance?

The desktop. But if you need a laptop, get it. I recommend alienware desktop over laptop.

right thanks for all your help