branded one...dell for example will need special drivers and would be a pain in the but. to do anything your self.
branded PCs usualy arent designed for home. they are designed for industry. if you want 500 pcs it would be better to buy from some one like dell as they will offer support and could be sued for damages if its their fault. why they make home pcs is becouse its a market they can sell in. its all about the mony. there is no reliabilioty difrence most branded PCs would be using inferior quality components inside the PC then the assembled one. hence you have less reliability.
the only advantage is it makes you feel good to have a pc with a label. but any one with some hardware knowledge would laugh at you as a idiot for buying a branded PC..trust me i do that lol.
assembled PCs would have a far greater bang for buck (Gigaherts is not everything also size of ram isnt key to performance either),
the assembled PC would be far more reliable then a branded one.
upgrading the assemled PC would be easier and cheaper.
branded PCs charge a bomb for component which only cost 20-45% of the price the brands charge you. for the upgrade
assembled PCs would be far more flexible on the hardware.....you can choose what you want....
assembled PCs are designed for UR need and in reality DELL pcs are not custum made for everyone. they come of the shelf and choices they so proudly parade are only limited and only a few variables occur so they make few of every combination...... assembled PCs doent.
also all the essential hardware will have at leats 1 year warrantee hence if it stops working you take it to the shop you got it from with the reciept and they will replace it for you. (my cuzin had 30gig hard drive, it got messed after 6 months by then the 60gig harddrive was 2 pound more expensive hence he paid 2 pounds to upgrade to 60 gig drive.)
last but not least assembled PCs are easier to maintian (you ask your mates for installing and get a replacement free of charge via warrantee)
also if you like branded PCs for their slick look and think custom PCs are shabby then check these cases out
http://www.cclonline.com/categories/CAS-MTNand for a video editing its not aboutthe ram its about how fast your PC can dump data from the ram (PC concius) to the hard disk (PCs Memory) and depending on the budget:
cheap: buy a 74Gb western digital raptor...its one of the fastest...for application storgae and media storage for editing and buy a 160 gig drive for data storage.
medium: buy 2 western digital raptors and combine them in a raid 0 (your amtes shiould know..if not not that dificult doent get scared) this uses the two drives simultaniusly and hence increases the rate the data can be transfered. buy one large drive for data storage.
expensive: buy 4 raptors and do em raid 0........very fast..
expert: buy a scsi drive they are WAY faster.
expert level 2: buy two and configure them in raid 0
expert level 3: buy 4 and raid zero....
(note scsi drives are usualy about 26GB but doent be put of. as they are hundreds of percent faster then a normal drive and better when it comes to video editing and raptors are also in same league only slightly inferior...)
TIP OF THE DAY.
make sure your system is cool. processor temop should be 45degC +-15degC. modern mother boards just restart the PC once a certain tempreture is reached to prevent the prcessor melting (60degC + is the red area)
any more question feel free to drop me a PM or ask me here.