Power Supply Needs for Modern Performance PCs

[Caxus]

The power supply in question: Thermaltake Silent PurePower TT-420AD

http://www.newegg.com/Product/Product.asp?Item=N82E16817153006

Now, i have to admit that i think people generally exaggerate power supply needs bit. But considering that a cheapo low amperage 300w was enough for an A64 3200 clawhammer and a 9800 pro and that a cheapo low amperage 350w was enough for the same cpu with an x800 xt pe, how would this guy fare with a 90nm A64 and an x1900 xt?

1) A bit low but probably enough?
2) Maybe, maybe not?
3) Total system suicide?

[Leonardo]

For that video card, I personally wouldn't go below a quality 500watt PSU. A 420? It's a crapshoot. If it has a high 12v amperage, then maybe it will work, but it's risking his money. The 1900's power requirements are much higher than the other cards you mentioned.

[Caxus]

For that video card, I personally wouldn't go below a quality 500watt PSU. A 420? It's a crapshoot. If it has a high 12v amperage, then maybe it will work, but it's risking his money. The 1900's power requirements are much higher than the other cards you mentioned.
12v rail is 18A. Is that enough?

[lemonlime]

12v rail is 18A. Is that enough?

Hi Caxus, Leo is correct.. the X1900 is a real pig when it comes to power. I'd recommend no less than 25A on the +12V rail for a card like that. Anything less is asking for trouble I'm afraid. If the system has dual +12V rails, its a little more tricky, but I'd recommend at least 18A per rail in that situation.

[Mt_Goat]

What is the value of your components? I ask because you are asking a cheap PSU to be responsible for powering parts that cost many times the cost of that PSU. I see all too often where people have problems from either an underpowered PSU or one that is just plain cheap. Some experience strange problems that all too often end up as the result of a cheap PSU. While others loose expensive parts and even whole systems when those cheap POS PSU's go bad. Why risk it when you can buy a good unit that will last through more than one system and have the peace of mind knowing you have quality that won't fail you? I once bought a cheap 600W PSU that went out and took $800.00 of motherboard, CPU, RAM and video card with it. Have I bought any more cheap PSU's since then? HELL NO!


I agree that you want no less than a quality 500W unit with no less than 25A on the 12V line.

[GHoosdum]

These fellows are spot on. When the video card is as expensive as the 1900 is, why cheap out on the PSU? Definitely go with a quality PSU with 25A or more on the 12V rail.

[Caxus]

Can anyone recommend a good 500w+ power supply that has 25a or more on the 12v rail that's in the $50-$60 range or would anything that cheap pretty much be junk? Also i've noticed that a lot of them will say that the 12v rail is 35a but it turns out they're talking about two separate 12v rails. Will those work or not?

[Mt_Goat]

My list from cheapest to highest without getting too carried away;

OCZ ModStream OCZ45012U 550W (http://www.newegg.com/Product/Product.asp?Item=N82E16817104154)

FSP Group (Fortron Source) AX500-A, 2.0 version, 2 SATA, PCI Express, 500W (http://www.newegg.com/Product/Product.asp?Item=N82E16817104934)

SILVERSTONE SST-ST50EF 500W (http://www.newegg.com/Product/Product.asp?Item=N82E16817256001)

OCZ PowerStream OCZ520ADJSLI 520W (http://www.newegg.com/Product/Product.asp?Item=N82E16817711002)

FSP Group (Fortron Source) FSP550-80GLC-R 550W (http://www.newegg.com/Product/Product.asp?Item=N82E16817104018)

SeaSonic S12-500 500W (http://www.newegg.com/Product/Product.asp?Item=N82E16817151024)

FSP Group (Fortron Source) FX600-GLN ATX12V/ EPS12V 600W (http://www.newegg.com/Product/Product.asp?Item=N82E16817104014)

SILVERSTONE SST-ST60F 600W (http://www.newegg.com/Product/Product.asp?Item=N82E16817163109)

[Caxus]

What about this guy?

http://www.newegg.com/Product/Product.asp?Item=N82E16817182013

[muddocktor]

What about this guy?

http://www.newegg.com/Product/Product.asp?Item=N82E16817182013

My feeling about power supplies pretty much mirrors the others here and I also feel that you get what you pay for. For a vid card in the class you are talking about, I would consider a psu in the class that mtgoat posted as a minimum. Personally, I love PC Power and Cooling's psu's over anything else I've used but they are pricey as hell. But again, you get what you pay for and the Turbo 510's are rated at 650 watts peak power and 510 watts continuous at 50° C, which is a realistic operating temp. But the others on mtgoat's list are also good quality choices and less expensive.

Realisically looking at what you need, you will probably need to spend around $100 for a quality psu minimum and with the prices of high end video cards, procs, mobos and ram, not that much more of an investment than a cheapo psu.