I am running an I7-920 @ 3.6 with an ATI 6950.Just reinstalled FSX w/ UTX, GEX, and UT2. Stock aircraft. Sliders maxed except ai traffic @ med high. 1920x1200Using AM 84.UT2 is really dragging my FPS into the low teens and I would figure that I am CPU bound but my CPU load never goes above 50% on 4 cores? I tried dropping resolutions in case I was somehow GPU bottlenecked but FPS doesn't move up, even at very low settings. What is holding me back?

I am running an I7-920 @ 3.6 with an ATI 6950.Just reinstalled FSX w/ UTX, GEX, and UT2. Stock aircraft. Sliders maxed except ai traffic @ med high. 1920x1200Using AM 84.UT2 is really dragging my FPS into the low teens and I would figure that I am CPU bound but my CPU load never goes above 50% on 4 cores? I tried dropping resolutions in case I was somehow GPU bottlenecked but FPS doesn't move up, even at very low settings. What is holding me back?

FSX typically runs one core at 100% and uses the other cores for texture loading only.So, you could have overall CPU utilization at 50%, but the one CPU core running at 100% is holding you back.Reduce some of your settings until you get acceptable frame rates.

DavidIt is not always cpu load which slows the system down but the speed that the processor can process the data (and is the processor only processing FSX objects and not working on other objects in the background), the speed of the Physical RAM serving the cpu and the transfer rate the processor/system can achieve passing the data to the GPU. Your processor should run FSX at reasonably high settings without issue. Even your fsx.cfg file if poorly set up could slow you down. Hyperthreading set in the bios can affect performance on some machines, as could the Affinity Mask setting if set incorrectly.Small peaks of 100% cpu usage are normal but as Bert says if they are prolonged you get slow motion city. There is a set of tools built into windows (better in Vista and Win 7) called PERFMON (Performance Monitor) and you can set counters so that you can see if your cpu, hard drive, ram, hardware etc is causing the bottleneck. It's not hard to use but there is a learning curve but fortunately with plenty of tutorials on the web. For example setting the counter 'Processor: % Processor Time' if this prolonged above a certain value and you have sufficient RAM then the cpu is probably the bottleneck. Likewise counter: 'System: Processor Queue' if this is above a certain value usually '2' you may also have a bottleneck. And so on there are more counters that can identify other problems including failing hardware. It also might be worthwhile looking at event viewer to make sure nothing untoward is happening that is causing your slow down. :( RegardsPeterH

There was a previous post about a user having simconnect issues and reinstalling UT2 fixed his problem.

Thank you for all your kind replies. Rebooted and turned off HT. Uninstalled UT2 and maxed the stock traffic to tax the system. Changed to AM 14.Things are a little better now but CPU 2 is now maxed while other cores are doing very little. According to Bert, the one maxed core is bottlenecking the others. Is there a way to get the other cores to share the load? Experiment with different AM settings? Other suggestions?(It never fails to amaze me how knowledgeable the users on the forums are!)

You are misinterpreting Bert's post. The main thread of FSX runs on a single core and there isn't any way to fix that. The threads on the other cores are not being bottlenecked by anything, rather they are texture and terrain loader threads which offload that work from the main thread. Your best bet for increased performance is a higher CPU overclock, or to figure out the FSX settings that give you the biggest payback for the kind of FSX experience that's important to you. One quick way of getting better performance is to completely eliminate car traffic, even a setting of 10% might degrade FPS by 4 or more. This guide is also recommended: http://www.simforums...topic29041.html. Good Luck!