I've been suffering through the "upgrade/spend more money on my rig" bug lately. Been thinking about a possible CPU upgrade but having my E4300 stable at 3.0Ghz with 2.0Gb of RAM, 8800GT 512MB and all the rest, I've decided that I won't be seriously upgrading until I get a good mobo which supports SLi and possibly DDR3, and CPU and GPU to match, even if that could be a year from now. So... money is jumping in my pocket . I get satisfactory performance, I think what I currently lack is DX10 for gaming, which means Vista. And while on the track of getting Vista.... I reason it out that it'd be worth to get Vista x64 and add another 2GB of RAM. The motherboard in my system specs is a P5B. I was thinking of adding the following: GeIL 2GB (2x1GB) PC2-6400C4 800MHz Ultra Low Latency DDR2 Dual Channel Kit I have 4 slots for RAM and am currently running mine (see system specs) at 833Mhz 1.9V 5-5-5-15, so I think I'd be safe to assume I can also run the above together also in dual channel without necessitating me to reduce my overclock below 3.0Ghz? I am currently using XP Pro 32 bit, so I was thinking to upgrade to Microsoft Windows Vista Home Premium SP1 64-Bit - OEM. That way I'd be getting DX10 for gaming and having 4GB of RAM recognised due to having a x64 bit OS. The total package would cost me USD190 including shipping and all. I know there is much better and faster ram on the market but I plan to keep using the 2x1Gb already in my system specs, so anything higher than 800Mhz would be overkill. But what is your opinion? Is it a good decision to spend the above amount on my rig? And more importantly, is the RAM I linked to above compatible to run in dual channel together with the ones I have so as to fill all 4 slots? Thanks!