[expert87]

Hi;
My pc has the following:
1- an MSI p965 platinuim mother board (which is huge)....the manual says it rquires at least 450 watts to work with full capabilities (including dual pci-e)

website: http://global.msi.com.tw/index.php?f...o=&prod_no=266


2- 4 Hard drives all western digital with a total of 990gb (the motherboard takes up t 7...but i had to stick with 4 since the case is kind of small )

3- a BFG 8800 GTS OC 512MB graphic card (PCI-E V2) the website says it requires at least 425 watts.
web site: http://www.bfgtech.com/bfgr88512gtse.aspx

4- a dvd-rom and dvd-writer.

it also has a pentuim D 3GHZ and 4GB 800 MHZ DDR2 Ram (2pcs)

now to the queston....iam not using the dual pci on my motherboard so i don't think i will need a full 450watts to make it work..
Iam using a kemex 500 watts power supply ((specefications: http://www.k-mex.com/UploadFile/FCKE...%20Version.pdf ))

i think the PSU is struggling with the other components.....when i first built up the pc it lookd fine....i would play crysis warhead 2hours straight with full quality and 1024×768 resolution withouth any discomfort....

But recently the pc restarts after playing the game for 20minutes.....temperatures after restart are CPU: 66 GPU: 68 motherboard: 40 and if i touched the power supply everything seems cool....except for the hot air coming outside the powersupply...(my pc is always uncovered for cooling reasons).

i tried to change some wires but the problem presists....do you think the power supply needs assistant?? i bought a stock power supply which says it gives upto 550watts (well, doubt it)...and iam thinking of adding its powers to the poor 500watts psu...but which combination do you recommend (i mean should connect the harddisks+cooling fans+dvd rom+writer to the stock and leave the big guy with the graphic and motherbord or what???...to be honest i don't want to risk the graphic card or the mainboard by connecting them to the stock)

Note: iam not using any extra extensions with the power cables coming out form the PSU...but iam using all the cables it has except 1...+the guy who sold me the PSU told me it can take far more than 500watts (well its expensive compared to a stock one! )

Sorry for the long question

[expert87]

come on guys, is it that hard?

[Oklahoma Wolf]

A good 500W unit should be able to run that. Trouble is, that unit is not a good 500W. A Corsair VX550 would do a lot better.

[expert87]

thanks for your reply
the thing is i just bought this thing and returning services are not supported here for PSUs...not even warranty....so do you advise me to add the stock one to this one? and in what order should i connect?
If a 500watts should do fine why am i facing the restart problem??
sorry for 2much questions but i want things to seem logical to me.

[RollingThunder]

Originally Posted by expert87

thanks for your reply
the thing is i just bought this thing and returning services are not supported here for PSUs...not even warranty....so do you advise me to add the stock one to this one? and in what order should i connect?
If a 500watts should do fine why am i facing the restart problem??
sorry for 2much questions but i want things to seem logical to me.

It's a lower output power supply that's not even UL listed with 65%efficiency masquerading as a 500 watt unit. Replace it.

[grumperfish]

What RollingThunder and the Wolf said. A decent name-brand 450-500W unit from a good OEM like Silverstone, CWT, Seasonic, etc. would be able to handle that system easily. However, an inefficient "500W" Kemex unit with 16A and 17A on each 12V rail isn't going to cut it. Not only is the unit going to have to run loud to supply anywhere near sufficient voltage for your parts, it's guaranteed to produce a fair amount of heat and can actually kill your hardware if voltages run too far out of spec (not even going to go into ripple issues).

Forget wiring up a second PSU as you'd just be wasting money, and look into a name-brand unit with ~32A+ @ 12V minimum, preferably on a single 12V rail in the specifications. It may cost a bit more to get a decent unit, but it's almost always going to be cheaper than buying new hard drives and videocards. Also you'll save money on your electrical bill from the reduced heat and added efficiency.


Good recommendations for power supplies can be found throughout this section of the forum.

[expert87]

I understand u guys but the option of replacing is not available now cause i spent my savings on buying the graphic card....I want a temporary solution for the problem.

SO do u advice me to share the load with the stock one?? and again what things should i connect with the stock and what i shouldnt??

sorry for the inconvenience

[expert87]

by the way the second power supply has a total of 25amp at 12 volts...if it helps
iam not sure if i undestand the rail thingy but i belive its a single 12v rail

[expert87]

guys i can't touch my pc untill some one answers me please....
the main power supply has two 12v rails with 16A and 17A for each
the stock one has a 25A at the 12V single rail (not sure if that is correct but its written on the psu....its a stock one after all)

seems like i have to stick with those two and can't replace te current one cause i lost my budget to an expensive graphic card (iam a univ. student)

i want to connect the 2 psu's since u guys said the 2rails psu can't take the sytem but i don't know which parts should i connect to each psu....i mean which psu should take the main load (graphic+mainboard) and which should take what is left....or any suggestions in connecting would be appretiated

[MARCI]

They indicated that you should not use that Power Supply, it is a poor unit, and risks damaging your more expensive components.

[BobbyBubblehead]

you could do with a PSU that delivers some good ampage across the rails with all that on tap. (I bought a 650 and had to swap for 700 before I even fired it up was`nt the 50Watts it was the ampage that made the difference)
get a good one and it will operate normally is my suggestion. understand its not the most straight forward option.

[MARCI]

Listen to Oklahoma Wolf, his advice on PSU questions should be treated as gospel. He is knowledgeable regarding construction, efficiency, and other factors regarding power supplies. If he says that the psu you have doesn't deliver it's rated power, and it's an inefficient design, it's because he's TESTED it, broken it down, and examined it.

[expert87]

ok i contacted MSI (my motherboard vendor)...he used some formullas and told that if i use a 500watts psu i will have 380watts for the graphic card but he said it is enough for my graphic towork!! here is what he said

does the mainboard actually takes all that energy??
Yes,your PSU(500W) is powerful enough.The output voltage of PSU is 12V,5V and 3.3V.VGA abd CPU are using 12V.8800's reted current is 26A.Those devices using 5v and 3.3V will use up 120W or more.The other 380W or less will make the 8800 card working normally.
Please refer to the below formula:
380W/12V>=26A.

i mentioned that my graphics need 425watts
by the way....iam in the middle east so some of the things we got here don't reach west countries....maybe that includes my psu? because k-mex is very famous in my country and it is expensive too.....(about 60$ )

anyhow i connected 2 psu's and distribted the load but when i pluged the cables (my pc works for 1 or 2 seconds when plugged then turns off) i heard a strange sound (maybe) and my heart stopped so i turned off the pc...disconnected the other psu and 2hours work is gone for nothing
guess i really have to buy a new one....so i won't play games tell next month :S ...the pc seems to work fine if no games are on...the cpu stock fan speed is 2.7 though...i am not sure but i think it used to go over 3000rpm before....
but with what the technical support said that means i will nead at least a 600-650 watts psu which means more bucks will come out

[Joe Public]

Hm, MSIs answer was weird. Anyways, your graphics card won't need 425W on its own, the 8800GTS card will probably pull about 100W. Still, I think Oklahomas advice should be heeded. If that PSU is causing the computer to spontaneously reboot, it could end up damaging your stuff.

And you have no warranty rights in your country? That means they can sell you anything and you have to bear the entire cost alone if it fails? Then I'd certainly be careful about breaking anything.

[expert87]

we do have warranty rights and even better than other countries....i can change any piece even after it warranty date passes and instaneously without returning to the factory (the dealer takes care of that)....but for some reason they told that psu's has no warranty....maybe its the shops iam dealing with or something....
i might consider dual psus solution tell i get a new decent psu...any one objects??

[grumperfish]

You could probably get by temporarily with dual psu's if you wire them up correctly, but don't push the system hard or do any gaming. Honestly you'd be better off just running the 25A unit and disconnecting all hard drives other than your boot drive, and remove the 8800 if you have onboard video on that board in the meantime though to be safe.


As far as a replacement unit, a good-quality 500W-600W PSU would power your system fine if it has a 32A or better rating on the 12V rail. 40A+ is a safer bet depending on your budget.

[expert87]

thanks a lot
thats the answer iam looking for

but r u sure a 40A PSU would be enough?

[wingman99]

what is the power supply that you got, can you run the other one by it self.


You only need good 500w psu use the PSU buyers guide and How-to guide, above sticky.

I have run two PSU's together to get me by for a month, what you need to do is use one outside to power your graphics card 6 pin plug you need to jumper the psu outside your case right after start buton is pushed.

If you really want to do this i will look up what i did, they also make a connector to do the job right.

[grumperfish]

Originally Posted by expert87

thanks a lot
thats the answer iam looking for

but r u sure a 40A PSU would be enough?

32+ would probably be fine for a Pentium-D and 8800, and 40 would be more than enough given your hard drives and optical drives.

My roommate's currently running a PD820 system with a G80 8800GTS and two hard drives under an 520W OCZ (single 12V rail at 32A) and it's more than enough after testing it with a DMM so you should be fine with something around that range.


Definitely follow wingman's advice for a temporary solution though as it should buy you plenty of time to upgrade the PSU properly.

[Aynjell]

Originally Posted by Oklahoma Wolf

A good 500W unit should be able to run that. Trouble is, that unit is not a good 500W. A Corsair VX550 would do a lot better.

My PC Power and Cooling 510 SLI has been running for nigh on 4 years now, and runs the stuff in my sig. With cap aging etc taken into consideraton, it's obvious my PSU is of high build quality.

I'm not sure of your PSU, though. I'd order up a new PSU, a good solid future investment might be the silencer 750, which you can get for 105$ on newegg right now. best bang for buck and it's actual potential output is more like 800+