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Discussion Starter · #1 ·
Hey,

i decided to upgrade my pc and so i bought an Nvidia GeForce 8800 GTS and a 530w power supply to power it.

I set everything up fine and everything was running perfectly, i'd been running Vanguard on highest settings with no sign of slow down for about two hours. Just as i was logging out there was a sudden noise and spark and my pc cut out, it also tripped out the power in my house and i had to reset the fuse box.

The pc wouldnt turn back on, yet was fine when i switched back to my old psu and removed the graphics card.

Does anyone have any idea what caused this? and also how likely is it that the graphics card is broken as well as the psu? With no psu I, I can't test the card.

thanks in advance for the help.
 

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Hi,

My guess is that the power supply was either defective to start with or not up to the job. I highly suspect that it was not up to the job, because it is not a real high quality supply to start with and also, you most likely need a bigger power supply with this unit. Could the video card have fried....well, yes, but let's don't cross that one until we get a real power supply in there.

Please review the Power Supply information under my signature area, and then use the calculator at the end of the document. When you get done, add 30% to the total and you will see the very bare minimum size of power supply that you need. When done with that add about 100 watts to make sure you have enough consistent power.

Don't buy another power supply of the brand that you have if you can get one mentioned in that document. You might be able to RMA this one if not too old, but try to get them to swap for a good brand name of a higher wattage. It will cost more for a quality power supply.

My best guess without knowing your total specs (you need to post your specs) is that you will need at least a 650+ watt power supply to pull that video card. Might want to look at the 700 watt OCZ on sale now at Tiger Direct. A great supply for a reasonable price.

Post back with questions/concerns.

Post back with questions/concerns.
 

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Discussion Starter · #3 ·
Thanks for the help.



I've bought this PSU from my local store so that i could check if my graphics card is fine. My monitor showed the boot screen when connected to the graphics card so it hasn't blown the card. I'm worried however that that doesnt neccasirly mean the card is fine, and that could still be damaged (i only went as far as the boot screen as i didnt have a hard drive connected). What do you think?

This new supply is 500w with the follow output:

+3.3v | +5v | +12v | -5v | -12v | +5Vsb |
36A | 36A | 20A | 1A | 1A | 2A |

I suspect it wont be good enough as a proper supply for my pc, but i just wanted to test my graphics card.

Here are my specs as requested:
CPU: AMD athlon 64 - 3200+ (2.0 ghz)
RAM: 1gb ddr PC3200, 512 ddr PC3200, 512 ddr PC2700 (thinking of removing the PC2700 as it means my other sticks have to operate at 2700 too)
Graphics card: GeForce 8800GTS
Hard drive: 320gb SATA II (LINK)
Motherboard: MSI RS480M2-IL (link)
Other: Front panel card reader, audio and 2 x usb2 ports.

The calculator says 263w + 30% = 342 + 100w = 442w.

My power supply was more than that, so what do you think the problem was?
 

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Hi,

Two things. First of all, the specs for your video card quote the following as MINIMUM requirements to run that card:
recommended power supply with +12 Volt current rating of 26 Amp Amps
Therefore, that power supply will not run that video card properly.

Second, I think you better take another look at the calculator, because the figures you came out with are not nearly what your rig takes. Be sure to list everything and the exact video card which takes about 155 watts alone from the initial watts you listed before the added 30%. Just go back and redo it and add the 30% and do a close recheck.

Note: The video card wattage is from my poor memory, but I will check and see if that is correct.
 

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Discussion Starter · #5 ·
Where did you find requirement?

I've tried the calculator again and got the same result, could it be that it isnt adding the watts for my gfx card on to it? I've selected everything.
 

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Where did you find requirement?

I did a google search of amp requirements, but didn't keep the link. If I come on it again this evening, will send it along

Here is a link for the wattage requirements of video cards. I think my memory was incorrect, I think that yours takes like 155 watts for that video card. You can double check since I will give you that link. If I misquoted, forgive me, has been a very long day.

http://www.atomicmpc.com.au/forums.asp?s=2&c=7&t=9354

I've tried the calculator again and got the same result, could it be that it isnt adding the watts for my gfx card on to it? I've selected everything.
 

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Discussion Starter · #7 ·
According to that thread, my card alone is 115w. I have no idea why the calculator is coming out as so low, i've put in my card, processor, hard drive, ram, front memory card reader, motherboard, dvd drive and fans i cant see what else i could be missing.

I've just found out that the blown supply only had 18A on the 12v rail, would this cause it to blow?
 

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Hi,

Yes, it sure could cause it to blow. I just ran your rig on the calculator (assuming you had a CD and a floppy on there, and came up with about 433 needed...adding the 30% took me to 563 minimum requirements. If I got those specs, you will need to get in to a bare minimum of a 650 watt power supply (and that would be tough), but with the 8800, I recommend highly that you purchase a 700 or 750 watt power supply. There is something you are missing on that calculator.
 

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Discussion Starter · #9 ·
ok thanks, no idea where i went wrong then :p

Do i need at least 26A on the 12v rail too? As im struggling to find supplies with even 20A.
 

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Hi,

Take a good look at the OCZ 700 watt, they have been on sale recently, but don't know if they still are. Tiger Direct had them for $100 bucks just last week and that is a $135 normal priced supply. With that card, you just need a lot of push, because that is a very power hungry card.

Oh, I think I must have put the 8800GTX instead of the 8800GTS card, so that will lower it a bit, but less than 50 watts off the calculation. Therefore, you could get by with maybe a 650 or so instead of the 700, but that does not give you any head room as new things come out. If it were mine, I would go for the 700 and it will last you for a while and you won't have to redo this power supply in the next year as you decide to upgrade something. I will take a look around and if I see any glowing deals on a good BRAND NAME power supply, will let you know. Please, whatever you do, buy a brand name that is in that power supply information, because if you don't, it will most likely not do the job for you.
 

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Discussion Starter · #11 · (Edited)
I've just looked at the OCZ power supply, it has 4 12v rails and only 18A on each of them, does that mean it wont be enough ? I thought i needed 26A.

EDIT: Another thought, my previous set up was running fine on 300w, all ive changed is swapped onboard graphics for an 8800gts (quite a step up :p), and swapped an IDE for a SATA, oh and removed a pointless pci 56k modem. Will that really require me to double my power supply?
 

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Hi,

That power supply will do a great job for you with total amps for that baby at 72 amps and that supply is one of the best for what you want to do. I would recommend that one in a heartbeat. You don't need 26 amps on the same rail. Hope that clarifies that issue. With the rig that you have that will give you headroom, so that if you want to add something in the near future, it will do the job, even if you upgrade quite a few components or get a new rig.
 

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Discussion Starter · #13 ·
ok, i'll get that one then, i'll go for the 600W though as i cant really afford the 700w.

Thank you very much for the help.
 

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Dave,

The 600 would be fine for that card you are running. (special note: after reviewing the power supply calculator, I put a more power hungry model of your video card in there, so that means approximately 50 watts less are needed, so a 600 watt supply would be fine and do a good job for you)
 

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Hi Dave,

That Seasonic is probably the most powerful power supply you will find in that wattage range and it would do the job for you. That unit is 85%+ efficient, has active PFC and is just a powerhouse. That is the exact same unit I have in this rig I am writing from and it is as good as it gets. Actually, the Seasonic is all I use in my personal machines at this time.

The 600 watt OCZ should also do the job for you. I do think either will run your rig after going back and reviewing the wattage and the fact that I had put the bigger model video card in the calculator than you have...That does make a wattage difference (50 watts or so less needed), so go for either 600 and you will be happy. These two power supplies are two of the best on the market and both are loaded with power........So, if you can spill for one of these dai has listed, lets get going on it and get this computer up and running.
 

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Discussion Starter · #20 ·
thanks very much for the help. i've decided to go for the OCZ one from memoryc.com.

would my 500 watt power supply with 20A on the 12v rail last me until i get the new psu?
 
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