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Whats the max watt I can use with my power supply?

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January 13, 2013 1:26:49 PM

I have a 250 watt power supply in my PC. Here's a picture of it


Whats the max wattage my graphics card can use with this power supply? Also what is the 12 volt rail etc. ?

Thanks
a b ) Power supply
a b U Graphics card
January 13, 2013 2:01:37 PM

The combined +5v and +12v rails can't exceed 218W. We can't answer your question without knowing the specifications of your system, but your GPU options are very limited.
a b ) Power supply
January 13, 2013 2:06:58 PM

Anything more than a HD7750 on that PSU would be foolish IMO.
Related resources
January 13, 2013 2:13:32 PM

You must have at least 500W of PSU these days. 250W? How old is that PSU you got?
a b ) Power supply
a b U Graphics card
January 13, 2013 2:17:42 PM

aqe040466 said:
You must have at least 500W of PSU these days. 250W? How old is that PSU you got?
This statement is false. PSU requirements are based on the hardware installed in the system; a lot of low powered systems will do just fine with a 300W or less PSU.
January 13, 2013 2:22:34 PM

GhislainG said:
The combined +5v and +12v rails can't exceed 218W. We can't answer your question without knowing the specifications of your system, but your GPU options are very limited.



Okay well it has

Amd Athlon 64 x2 4800 @2.5 GHz which uses 65 watts
1 sata hard drive
I don't use my dvd drive so I unplugged that to save power

I'm not sure about this but from what I've read 12 volt rail @ 14 amps means I have 168 watts. My CPU takes 65 watts plus lets say 10 watts for my hard drive. So I have 93 watts left. I'm looking at a Radeon 4650 which has a TDP of 55 watts. So all in all it should use about 130 watts.

Am I right?
January 13, 2013 3:08:48 PM

So would that be okay on my system? Nothings gonna blow up or anything right? lol
a b ) Power supply
January 13, 2013 3:58:45 PM

I wouldn't recommend the 4650 due to its old age.
January 13, 2013 4:10:03 PM

FinneousPJ said:
I wouldn't recommend the 4650 due to its old age.


I don't really game much, the first need for speed most wanted and some gta sa is about it. Should be fine for that.
a b ) Power supply
a b U Graphics card
January 13, 2013 4:33:44 PM

The 6450 (DDR3 Version) ONLY uses 8 watts @ idle and 25 Watts at max. Which would be a much better choice given your PSU.
http://www.techpowerup.com/reviews/Sapphire/HD_6450_Pas...

Didn't see manuf, Looks like a Liton (made for HP).
These are generally low-end PSUs. Manuf specs are always suspect on these PSUs as the ratings are at ambient temp and often as the PSU heats up deregulation sets in and you may only get about 60->80% of manuf spec.

For continous operation I would consider max avail power for +12 V rail at 116->135 Watts
Above 116 Watts Usage (12 V Rail) - can any one say Russian Roulette or Crap shoot.
The PSU may last 3 years, then again it may last 10 Min under a heavy load. If it goes you also take a chance that (unlike quality PSUs) it may take part of/all of remaining components.

My Recommendations on PSUs is that if not a tier 1 or 2, do not run above 50% of rated Manuf specs.
January 13, 2013 4:55:02 PM

RetiredChief said:
The 6450 (DDR3 Version) ONLY uses 8 watts @ idle and 25 Watts at max. Which would be a much better choice given your PSU.
http://www.techpowerup.com/reviews/Sapphire/HD_6450_Pas...

Didn't see manuf, Looks like a Liton (made for HP).
These are generally low-end PSUs. Manuf specs are always suspect on these PSUs as the ratings are at ambient temp and often as the PSU heats up deregulation sets in and you may only get about 60->80% of manuf spec.

For continous operation I would consider max avail power for +12 V rail at 116->135 Watts
Above 116 Watts Usage (12 V Rail) - can any one say Russian Roulette or Crap shoot.
The PSU may last 3 years, then again it may last 10 Min under a heavy load. If it goes you also take a chance that (unlike quality PSUs) it may take part of/all of remaining components.

My Recommendations on PSUs is that if not a tier 1 or 2, do not run above 50% of rated Manuf specs.


I can't use any radeon 5xxx series+ plus as my motherboard doesn't support pcie 2.1

Yeah the manufacturer is liteon. I don't want to take the risk with the 4650 in that case. What would you say is the best low power card that will allow me to play stuff like NFS Most Wanted 2005 and GTA San Andreas? Doesn't have to be max graphics.
a b ) Power supply
a b U Graphics card
January 13, 2013 5:12:09 PM

Understand, problem is I'm not a gamer. So someone else can help out there.

What spec is your Pci-e slot. Most newer cards are back-wards compatable. Most 2.1 cards play fine in 2.0 slots, a few DO have problems with a 1.0 slot. Generally you can get a good idea if it will work by reading both prof reviews and user reviews.


Here is a review that shows it running on a pretty old system:
...Quote:
Cons: None so far.
Other Thoughts: My Build:
Refurbished Dell OptiPlex Desktop
AMD Athlon 64 X2 2.6GHz
4GB DDR2 400 (4 x 1GB) Ram
1TB HDD Capacity
Radeon HD 6450
Windows 7 Professional 32-bit
...End quote:
Ref: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

a c 111 ) Power supply
a c 109 U Graphics card
January 13, 2013 5:20:54 PM

Yes you can.
January 13, 2013 5:36:10 PM

RetiredChief said:
Understand, problem is I'm not a gamer. So someone else can help out there.

What spec is your Pci-e slot. Most newer cards are back-wards compatable. Most 2.1 cards play fine in 2.0 slots, a few DO have problems with a 1.0 slot. Generally you can get a good idea if it will work by reading both prof reviews and user reviews.


Here is a review that shows it running on a pretty old system:
...Quote:
Cons: None so far.
Other Thoughts: My Build:
Refurbished Dell OptiPlex Desktop
AMD Athlon 64 X2 2.6GHz
4GB DDR2 400 (4 x 1GB) Ram
1TB HDD Capacity
Radeon HD 6450
Windows 7 Professional 32-bit
...End quote:
Ref: http://www.newegg.com/Product/Product.aspx?Item=N82E168...


It's Pci x16 1.0. There have been one or two reports on google of people having trouble using 5xxx cards on the same pc as mine. I accidentally ordered a 5450 which is coming tomorrow. I'll see if it works but I'm not hopeful.
!