I recently switched from an Ati Radeon x1650 pro 512mb card to a HIS Radeon HD5450 1Gb card, and I am experiencing severe stutters whenever there is a cumulus cloud in the sky in FS9. All other cloud types present no issues.I'm also running FSX / Acceleration with the same HDEv2 clouds installed, and this problem is not there in FSX. With the 1650 card, I could run the HDEv2 high resolution cumulus set with no noticeable impact on my frames (locked at 20fps)but with the 5450, even using the 512 resolution set, the frames bounce between 2fps - 15fps and the game stutters and jerks like a slide show. I wiped all of the old drivers out from the 1650 card, and updated to the current ones for the 5450 card, and installed the most recent version of CCC. Have I made a mistake in the card selection? I did buy this one based on its price, and what I thought was bang for the buck, so it wouldn't surprise me.Surely a 1gb card should at least be matching the performance of the 512mb card, and in all areas aside from the clouds it does, and even surpasses it. I can hold a steady lock of 35fps, but I choose to stay at 20fps for MP purposes, and I'm now able to run at 1440x900 screen resolution, whereas with the 1650 card, I could only manage a 1024x768.Any suggestions? I really don't want to do a reinstall if I don't have to, but I'm out of ideas.Thanks for any & all help. :)

Hey Shane, It's not a memory issue I think but a driver issue. I would check around for the latest drivers ( but newest are not always the answer). Some ATI forums have reported improvement/fixes for these but I cannot direct you to a certain thread. Will take a bit of exploring to find the right driver I think. Might have to experiment with a few different driver sets for the best result. Check a few of the simmer's specs (in their signatures), in these forums to see who are running ATI 5000 series cards and ask them what they are using. Just a few tips. Hope that helps.Clutch