My FSX Computer....Gigabyte EP-45UD3PQ96504x2gig sticks of Gskill 1100 @ 5/5/5/15/48MSI Twin frozer2 GTX560Ti with 1gigWestern Digital 160gb sata system driveWestern Digital 1Tbyte Sata @7200 rpm FSX and addons driveXpPro64bit OSUTX, GEX, REX, Orbx, NGX, ASEOverclocked at 4.05 FSB @ 450 and memory running at 1080The above computer was running FSX extremely well with most settings maxed using the BP=0 tweak for a while. With the NGX I was able to get a very smooth 30fps and no microstutters.About a month ago I was building a living room media computer and plugged an old HD into the FSX computers extra sata port to format it before installing it into the living room computer case. At the same time I updated the FSX computer with the latest windows updates, one of the updates was an update to winxp64bit.The next day I purchased, installed and started flying the Milviz T-38 from Van Nuys to LAX where FSdreamTeams LAX scenery is. I noticed after passing the hills from van nuys to lax that I was getting some serious stuttering. The stutters were more like half second pauses as I passed over SMO on my way to LAX. At the end of each pause a bunch of autogen would load and then it would pause again. I circled to the left over LAX and started a left base for SMO. The stuttering and pauses got so bad that I just quit FSX, reebooted and started FSX to load the NGX at Van Nuys as I use the NGX as a benchmark when checking my FSX performance. The NGX was stuttering really bas as well. The stutters weren't tied to the hard drive as I could see that the hard drive light wasn't on durring the stuttering. It seemed more like an issue with the ram or the PCIE bus. Anyways, I spent the next week trying to figure out what the problem was and even got rid of the old GTX285 and replaced it with the 560Ti. That didn't fix anything.I then reformatted my two drives and did a clean install of xp64, installed all of the windows updates on the system drive, and installed FS and everything else FS related on the FS drive. Gave the sim a try with the NGX and still was getting these damn stutters. I then tried changing some of the FSX.cfg settings. Well the biggest difference came when I turned on Bufferpools (as I was running with BP=0 for the longest time just fine) and the stuttering changed from stuttering pauses to a high frequency micro stutters only when I pan my view from both inside and outside of the VC. I also noticed that when compared to before, my framerates were on average 5 frames lower than when the computer was running fine. I figured there was something wrong somewhere with my computer. I ran some torture tests and stability was good, checked the bios settings and everything was like it was before. I then started changing some bios settings, mostly with ram timings to see if there was a problem with my ram, but everything seemed fine. There is one small issue that I can't put my finger on and it may actually be related. I noticed with everything the same, that my processor cores don't get near as hot as they used to when the system was running fine as well as the weird finding that I can now trim my Trd ram timing all the way down to 8 with perfect stability! Now when I overclocked this comp, I was unable to run Trd timing any lower than 10 or the system wouldn't boot. I just spent a good part of today trying to get this thing running well again and I got rid of the MicroStutters by adding a Poolsize=16000000 to the cfg. After adding the poolsize line and increasing it 160megs, I can now fly the NGX with no panning microstutters, but my frames are still on average 5 frames lower than they were before. Now the weird thing is that when my comp was running well, adding the poolsize tweak to FSX caused less performance than running at BP=0.So, in a nutshell, after plugging an old sata drive into my FSX computer and installing a windows update, FSX has slowed down about 5 frames and the best FSX cfg tweaks have done a 180 degree turn. Things that worked in the FSX cfg before, don't work now and things that work now would have slowed the FSX performance down before.I have reinstalled the OS, FSX and all the addons. I have switched GFX cards. I have even tried running the machine on just half of the memory. I have reinstalled drivers, installed old drivers, downclocked, upclocked and stock clocked. I have run Memtest, and other diagnostic programs and have yet to find the problem...The only other symptoms other than poor performance in FSX are... Lower core temps and the strange ability to lower my Trd timing on my ram to a superhuman setting of 8.All this started happeing after plugging in an old drive and doing a windows update.I would like to get FSX running well again and I believe it is a hardware issue. But I'm not sure.A few things that come to mind are....1. My PCIe Bus is having latency issues (Which might explain some of the sound glitches I have been having and the fact that I can't run the BP=0 tweak anymore)2. My processor is having issues (But if so, then wouldn't I see some instability issues?)3. The Memory controller on the MB is going bad (Then again, the computer is stable)What would cause Core temps to drop with everything else being the same? What would allow me to run a much faster timing than before? Is it possible that my computer is running an actual clock speed slower than what is reporting in CPUid or any of the other diag programs?Could plugging in an old hardrive somehow damage the MB? Could a win update to XP64 actually hurt performance?I could sure use some help or ideas trying to figure out whats happened to my comp.ThanksJB

Could plugging in an old hardrive somehow damage the MB?

No, but it could spread a virus to your PC, and a virus could be causing the slowdown you are reporting.Also make sure you defrag your Windows HD after updates.Could also try to let FSX rebuild four fsx.cfg.Cheers,- jahman.

No, but it could spread a virus to your PC, and a virus could be causing the slowdown you are reporting.Also make sure you defrag your Windows HD after updates.Could also try to let FSX rebuild four fsx.cfg.Cheers,- jahman.

Since the slowdown, I have reformatted both drives and clean installs. Yep have defragged and ran virus scans. What do you think bout the core temps and the ability to run really fast timings?Thanks for the reply

Sorry, out of ideas here. Perhaps someone else can chime in?Cheers,- jahman.

Thanks for the replies though Jahman...Couple updates here. Still doing tests. Set bios to optimized defaults and then started the OC from scratch. Rebuilt the FSX cofg once again and only added a few tweaks.This is what I've noticed. Overall FPS has slightly come up but I am getting very large dips in the counter. from 40-11 every 10 seconds or so. FSX is playable, but I still wanna see if I can fix it. I notice the biggest performance hit when the mouse cursor is onb screen and moving. Just by moving the cursor I can get the FPS counter to stay at around 15-11 fps. As soon as I stop moving it but keep it onscreen FPS jumps to around 15-19. As soon as I hide it, it jumps to 30-40. I have always had a Performance hit on the mouse cursor, but nothing more than 5 frames with the NGX. I am still getting slight stuttering when I pan my view with Tir after leaving the view idle for more than 30 seconds. My 1 gig gfx card is always maxed out to the limit of its onboard memory. This was not the case before the slowdown. It seems like the memory in the GFX card is slow to load and refresh, but I know it's not the card as it's brand new. I'm thinking the processor is just old and tired or the onboard memory controller or PCIe bus is just old and tired. My vdroop on the voltage from the processor is pretty high. Bios cpuvid is set to 1.35, idle voltage is 1.29 and underload it's 1.25. So as you can see, the bios is having lots of issues getting commanded voltage to the cpu. I was running the voltage on load line enabled, but I just disabled that and am running without loadline enabled to see if it helps.Any comments observations would be great.JB