Yup, gonna shed more info to the newcomers and newbies on the power supply wattage myths.
Many people get the idea instantly that bigger watt PSU = stronger. WRONG!
The number may be correct, but it is possible that the power supply cannot provide that much power at peak usage. It is merely an advertising number for some companies. When the PS gets hotter, sometimes it can't provide the same "wattage" as it originally states.
This is a pic I can describe it with:
Newbies make this mistake often times, even I did a long time ago before I started researching about power supplies.
Here is a good example I can show you.
Newegg.com - Antec Basiq BP-350B 350W ATX12V Version 2.01 Power Supply - Power Supplies
Antec Basiq BP-350B 350W ATX12V Version 2.01 Power Supply - OEM
Output
+3.3V@20A,+5V@20A,+12V1@10A, +12V2@13A,-12V@0.3A, +5VSB@2.5A
This PSU has dual rails (12V1, 12V2) - Total Amperage available is 10A+13A = 23A total.
Note it's 350 Watt listed.
LOGISYS Computer PS480D-BK 480W ATX12V Power Supply - Retail
Newegg.com - LOGISYS Computer PS480D-BK 480W ATX12V Power Supply - Power Supplies
Output
+3.3V@28A,+5V@36A,+12V@16A, -12V@0.8A,-5V@0.5A,+5VSB@2
This PSU has single rail (12V only) - Total Amperage availabie is 16A = 16A total.
NOTE it's 480W listed!!!
Notice the distinction now? The Antec 350W will provide MORE juice (by 23A-16A = 7A) to the powersupply than this random Logisys 480W power supply!!
This is the basic to determining how much power you need. You figure out the Amperage the card requires, then you subtract that from your total PSU's amperage. After you got that, you make sure you have a few more Amps open for the rest of your system. Like a 34A (Can be Dual rail by 12V1@17A, 12V2@17A) power supply will provide enough juice for a 8800GTS that requires 24A of power at peak performance.
Next eye catcher:
Newegg.com - Broadway Com Corp P4OKIA600-Blue 600W ATX12V Power Supply - Power Supplies
Broadway Com Corp P4OKIA600-Blue 600W ATX12V Power Supply - Retail
Output +3.3V@32A, +5V@50A, +12V@24A, -5V@0.5A, -12V@1A, +5VSB@2A
Another Single rail PSU,
600 watt!! Notice WTF now? 24A on 12V only. This power supply can provide just a tiny 1A over the 350watt Antec!!!
This is what you need to keep your eye on when you buy a video card. And this is also why brand names like Antec, Fortron, Sparkle, cost MORE even though their wattage listing is less than the competitors.
Find out what AMPERAGE you need, not the WATTAGE. If you go by wattage you may choke your system in the long run after 3-4 years, when one day your video card goes kaput.
The power supply is the most important part of your system -- that is what is providing the energy to everything. It is like your blood circulation. If you don't keep it clean, it will contaminate and eventually kill other parts of the computer like motherboard, video card, hard drives, etc etc!!!
I cannot stress this enough. If you would like to learn more about this just ask.
if you buy power supply by wattage number, you are missing out on a lot of information!!!