I have a 650 watt power supply in my older dell xps. Its about 3 and a half years old I would kill to know what the power on the pci express video card slot is. Becouse I want to buy a new video card and idk what it can handle?

I don't know the specs personally, and being a dell they aren't the most forthcoming with detailed info, but from what little I could see they list a few cards with that system, so knowing what these are you can get an idea what you have:-

Personally I would be looking at the PSU, and finding out what that can supply, my guess is for the most part you should be fine with anything you get, unless you are thinking toward getting one of the latest cards out built for extreme gamers, because they are very powerful it may mean the PSU can't handle it, so if you wanted to say the kind of card you are looking at, and what you expect to achieve from it compared to why the current card can't presumably give you, then people may be able to offer more specific help, not being a gamer myself I wont be able to say too much, but hopefully this gets you started.

Hi dude,

What i will recommend is leave the old power supply and get an upgrade - Thermalteke - this brand managed to resolve all power problems on old PC's. I have old XPS 600 and i have add it Thermal take 400W power supply - it will fit your cd slot. Now i have upgraded my graphics in to G-force GTX 275 OCX - grt card.
Thermaltake you can buy on amazon - lifetime warranty.
Hope it helps

Are you sure that you mean voltage? Pertaining PCI-e slots, they are all designed based on a specific standard that should apply to all motherboards. I'm not sure on this (so don't quote me on it) but I think that different pins on the card have different voltages for those that carry voltage & not data. Based on that I think what are you referring to is wattage. That doesn't have anything to do with the slot but with the psu. I'm not a PSU expert but, depending on your card, 650 may be enough. You should check out power Supply Calculator to see how powerful a PSU you should have. What you do need to check on your PSU is to see if it has a PCI-e 6 pin cable designed to carry the necessary power specifally for supplying graphics cards with more power than the slot provides. This is because many of today's cards require that so if the card you want has that extra power port you need a PSU with that PCI-e cord otherwise your card won't get enough power to function correctly. Does that make sense?