Re: Artifacting on aero.
Is your card one of those factory "overclocked" editions? If so, you may need to turn down the specs to stock. 86c is very hot, but that may be normal for your card, I can't say. You may want to look into after market cooling solutions just as a precaution. It'll help your card run longer, anyway.
edit: I don't know anything about the power saving mode, sorry.
[CPU: e6600 @ 3300 MHz] // [MB: ASUS P5N-E SLi] // [RAM: Patriot 'eased latency' PC2-6400 @ DDR800 5-4-4-12-2T] // [GPU: 8800GTX @ 650/1000/1600 (volt modded)] // [HDD: 2x Cavier 500GiB stripe] // [Chassis: Thermaltake Armor VA8000 (black)] // [PSU: Aspire(Apevia) 680w] // [OS: Windows 7 Ultimate x64][Cooling: water cooled GPU and CPU]
^ (9/7/2010): Ha, I remember when that was the stuff. My water cooling has since leaked and fried my mobo. So now I'm rocking an MSI laptop with an i5 430m :)