Flight Simulator fans are often left scratching their heads after installing FSX on their existing machines, because it is an extremely demanding program. However, addressing it has proven extremely difficult, in part because typical solutions such as an ultra-powerful graphics card don’t work, and in some cases, such as with SLI, actually slow it down!
FSX is what is known as CPU-bound. What that means is that you are generally limited by the CPU, not the graphics card, RAM, or other components. This is in stark contrast to most games, because they rely heavily on graphics cards. Even the most demanding games, like Crysis, will vary widely with different graphics cards, but won’t be affected much by CPU changes. Even though FSX is CPU bound, you still need to give it enough RAM and graphics performance so that those factors don’t limit you. This is what you need.
RAM: FSX is a 32-bit application, so you can’t use more than 4 GB of RAM. If you’re building a new system based on the Core i7 architecture, getting 6GB of RAM is more than enough and pretty cheap too. RAM speed doesn’t really affect FSX performance.
Hard Drive: In general, FSX performance isn’t affected too much by the hard drive, except when loading textures. While some people like to use a hard drive just for FSX, it’s not necessary. However, if you choose to go that route, I highly recommend an SSD for its near-zero access time.
Graphics Card: FSX doesn’t respond well to ATI cards, plain and simple. If FSX is important to you, then don’t get an ATI card, period. All non-integrated Nvidia-based graphics cards work as well as can be expected, but in some cases, having more video memory helps. Go with something above 512MB if you can. I recommend the GTX 260, 280, 275 or 285. Do NOT get a dual GPU card or use SLI, because this will really limit performance a lot.
CPU – The problem. Let’s clear something up right away. FSX likes Intel CPUs, not AMD. There is no debate on this. Then there is the question of faster dual cores vs. slower quad cores. I’ve extensively tested a number of systems, so I can tell you this: FSX likes the fastest possible clock speed, above all else. If you’re comparing a 3.33 GHz dual-core to a 2.66 GHz quad-core, the dual will be much better for FSX. While FSX supports multiple cores, it relegates secondary and tertiary tasks to the other cores and doesn’t affect framerate as much. You could even say that the frame rate in FSX scales directly with the CPU clock speed. This is the reason many people are looking to overclock. I wouldn’t be interested in running FSX with a sub-4GHz CPU. If you can get a quad-core that can overclock and run stably at 4GHz or higher, go for it, but if that’s difficult then definitely go for a super fast dual-core, like the E8400, E8500 or E8600 Core 2 Duo. models and overclock it to 4.3 GHz or so. I found the Core i7 920 to be the best value, because not only is it faster clock-for-clock, but it also overclocks very well – I use mine at 4.2GHz all day.
So why is FSX like this? Well, FSX was designed at that time, right before dual core CPUs came out and clock speeds increased. Remember the 3.8GHz Netburst P4? Basically your engine is old and not much can be done at this point. In addition to the hardware recommendations above, I’d also say that you run FSX on Windows 7 or Vista 64-bit, have all your drivers up to date, and are looking to get the REX (Real Environment Xtreme) plugin, because it doesn’t just look great, it actually helps your frame rate. Happy simulation!
