# 300W power supply sufficient?



## tjhafen (Nov 27, 2007)

I'd like to upgrade the graphics card in my HP m8100n without replacing the power supply. The computer comes with a 300W psu, and the card I'm looking to get says you should have 350W to run it. I called XFX and the tech guy told me it would probably run OK since it is close to 350W, but that he couldn't guarantee anything. I've found a few reviews online from people who have run this card on 300W and say it works great. I'm just wondering what possible problems I could run into if I get this card. Will it not run properly? Is there a possibility of damaging my computer? Any help would be appreciated.


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## HawMan (May 12, 2006)

I dont recommend it because 350W is really the Absolulte minumum. The PSU will probably die over a few weeks/months with the strain and blow out - And this could take the Motherboard/CPU with it.


Other people may have ran it on 300W but that could of been a Quality PSU supplier with more Volts on the 12+ Rail.


:wave:


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## Fanible (Nov 23, 2007)

tjhafen said:


> I'd like to upgrade the graphics card in my HP m8100n without replacing the power supply. The computer comes with a 300W psu, and the card I'm looking to get says you should have 350W to run it. I called XFX and the tech guy told me it would probably run OK since it is close to 350W, but that he couldn't guarantee anything. I've found a few reviews online from people who have run this card on 300W and say it works great. I'm just wondering what possible problems I could run into if I get this card. Will it not run properly? Is there a possibility of damaging my computer? Any help would be appreciated.


Well if it killed your power supply, it might. Or the computer just simply wouldn't power on.

What kind of graphics card is it, and what all do you have running on the power supply?

Honestly, though, a 400-500w PSU costs little to nothing. There's really no reason why you shouldn't pick a new one up.


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## tjhafen (Nov 27, 2007)

The card I'm looking at is the XFX GeForce 8600GT XXX 256MB (PVT84JUDD3). I have two DVD drives hooked to the power supply and a TV tuner card. Does replacing the psu void a computer's warranty? Is it difficult to do? I'm not extremely computer savvy, and don't want to mess around in there more than necessary.


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## Fanible (Nov 23, 2007)

Um... it's _possible_ it might void the warranty, but I really don't see replacing the power supply as any different than you adding or replacing a new video card. I haven't bought a pre-manufactured computer in 10 years, so I'm not really up to snuff on their policies. I'd imagine if, for example, the computer stopped working for whatever reason after you installed it, they'd probably say your warranty is no longer valid.

You're definitely going to want the new power supply if you're going with that card though (and make it at least a 500w if you can help it). If it's really a concern, you can call or email said company and ask before you look into gutting the computer.


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## Tumbleweed36 (May 14, 2005)

I would certainly not recommend you trying to run it with a 300 watt power supply. The danger here is that when you use an underpowered power supply, then it can cause problems and possibly damage other components like memory, motherboard, etc.


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## tjhafen (Nov 27, 2007)

The HP tech guy told me not to worry about replacing the psu, that I should just install the card and it would be fine, and his supervisor confirmed it. Does that sound right?


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## Tumbleweed36 (May 14, 2005)

IMHO, he doesn't (neither of them) know what they are talking about. You have to make the choice, but if it were my choice, I would not risk it.


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## ebackhus (Apr 21, 2005)

Both of them should be fired.


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## tjhafen (Nov 27, 2007)

So if I get a similar card from PNY that has a minimum power supply of 300W, should I be OK?


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## ebackhus (Apr 21, 2005)

You'll be pushing the design limits of that PSU. If it works it likely won't work for very long.


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## tjhafen (Nov 27, 2007)

Thanks for all the help. It looks like a bigger psu would be a worthwhile investment.


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## Thecasualfly (Feb 12, 2008)

just a quick question, i have a 300 watt power supply as well, would my new Geforce 6800 xt be able to work on such a low power supply?


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## Tumbleweed36 (May 14, 2005)

No, has to be the answer. The manufacturer's recommendation for that power supply is 350 watts with a minimum of 18 amps on the +12 rail. IMHO, that is way too low also.

To try and run it with a 300 watt power supply increases the chance of damaging both the video card and the other components of your computer like the memory and motherboard. 

Don't try to run it until you get a decent power supply unless you are in to replacing parts on your computer.


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## 1 g0t 0wn3d (Jan 31, 2007)

The 6800 took a huge amount of energy (about as much as a 7900gt) the 300 watt bestec only has 19a on the 12v and is not enugh for a pci express card which has a min of 26 amps


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## zaknafein72 (Jan 8, 2008)

tjhafen, I had exactly the same situation as you, looking to buy an XFX 8600gt and run it on a 300w power supply that came with my computer. However, if no one else has convinced you, that was a very bad idea. Within hours, the computer started crashing and became unstable, including refusing to boot and beeping from the bios. I bought an Antec 430W Earthwatts psu and my rig has been running fine ever since. I would reccomend the antec 430W either earthwatts or trio as running that card well with fairly low cost (I picked up my psu for only $40 as it was on a rebate at the time.) 

Also, a big word of caution: the XFX 8600gt runs very well, it is a very nice card. However, if you care at all about noise, the card is VERY loud, a low constant drone that you can hear from other rooms easily when the house is quiet. The fan cannot be throttled or turned down as it does not have a control lead, so it runs at 100% all the time. I have since purchased a Zalman VF900-Cu cooler for the card and it runs very well and quiet and cool; however, this cooler was around 40$, so if you want to minimize price you might investigate buying another 8600gt that is quieter, perhaps this one:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814127286

Only 72$ right now, runs on passive cooling so no noise, and you get a free copy of The Witcher. I don't know all that much about MSI, so you might want to look for reviews of the card first, but the customer reviews are very positive.


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## magnethead (Mar 18, 2006)

I have a 7800GT running off a toughpower 650 watt PSU with a C2D and 3 hard drives and i've never noticed the PSU fan pick up speed so i'm only harnessing aout 25-40% of the power. for refrence.


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