I am building up a new system and this time it'll be an ITX. Components are, IB 3750k @ 4.5ghz (max). Itx z77 board , 8gb ram, HD6850, 1SSD and 1 HDD. I read that I don't need crazy psu at all, would 300watt itx psu's be sufficient? I will be using good brands. updated: For those that are in similar situations, here is an update. Components : 3750k @ 4.4ghz, Asrock itx z77e board, 8gb ram @ 2ghz, HD6850 OC, 1 SSD and 1 HHD, 2 140mm Fans. I purchased a TFX PSU. It is 80+ approved 350w (400w max) by Powerstation ( a korean brand). I can't find any review but rating was good and total 44amp from 12v as well. It is high quality (coming from Antec earthwatt 450) and size is about 1/3 of the ATX psu. With it all, I have no problem what so ever with using it for past week in both work and gaming. I've ran all the benchmarks without problems and it doesnt have problem rendering in vray and various games. I really thought you needed a high powered psu these days but I guess things got more efficient. So for 1gpu set ups, I recommend good quality 350w. And I really wanted to keep the GEMIN II cpu cooler and Accelero I purchased from ZAP long time ago , so I built a custom case to keep all the sizes to minimam yet to have a vertical gpu configuration(like Raven). Not finished with details on the case, but so far so good. I am now debating Delid or not to delid... ahhhhh 4.4 @ 1.25v and it maxes around 70c.