1)I am planning on buying a new video card, so I need a new power supply. I have a Dell Inc. manufacture one, L350PD-00 (I bought this desktop, I didn't make it, and this power supply isn't mine). So I need an advice on what things should I look for before buying a new one. I would like it to be at least 800 watts (right now it's 350 watts).
2) What things should I consider before buying a new video card (And yes, I don't mean my budget or anything like that), I mean like the first thing I should consider is my power supply that I need to upgrade, is there anything else I should consider?
OK so you've given the model of the power supply unit in the Dell computer, but you haven't specified the model the Dell computer is. From what I can determine about that specific power supply its from a Vostro 460 Mini-tower? Please correct if I'm wrong. It's important to understand the model of the machine so that it is possible to identify what (if any) its expansion potential is.
You may encounter issues trying to fit an 800 Watt power supply into the case. Since 350 Watt supplies can come in low profile form factors, and if the case is a Vostro 460 it's likely that it ill be a low profile PSU, you may be restricted as to what you can actually physically install.
Please provide the model of the Dell computer that we can help you out further!
Before purchasing a new video card, find out how many amps does the 12v deliver on the PSU (40 amps on a 800W PSU is usually a poor quality one that spits out magic smoke). Then go find the GPU of your choice and see if it is able to accept the minimum amount. A good quality 750W PSU would be enough to power a GTX 690. Then go find reviews on the internet to see if it has good ripple suppression on its volt rail, and delivers its promise on efficiency. Then go on Newegg or other online retail store and read user reviews on reliability and customer support. The Seasonic X-760 which i have powers my systems nicely. It has very good ripple suppression. The SeaSonic Platinum 860W with 71 amp and 4 PCI-E connectors is more than enough for any system.
1) Yes it is Dell Vostro 460 Mini-tower, so if I can't fit it in, then can I just put everything in another case?
2) It seems from the previous comment I would need to buy a new video card, so I think I can surely fit it when I buy another case. Yes, my motherboard got that PCI slot. Right now I am playing on ultra settings any game, with my Radeon HD 6670, it's not because my video card is bad, it's because I feel like it's gonna die soon, the fan doesn't always work properly.
3) Budget - $500 max. I got core i5, 8gb memory, and Radeon HD 6670. I prefer SLI. I like AMD more.
SLI is dual graphics for Nvidia not AMD. But that's irrelevant.
Regular size PSU should fit fine.
From the pics I could find online most graphics cards should fit just fine but you might want to take some measurements before you buy just to be sure.
500 to 600 watts is all you will ever need in a power supply, you can't have dual graphics on that motherboard so you will never need more than 500 watts (excpet for in a single card dual gpu solution but that's beyond your budget).