I'm recently getting stuttering on every game with the GTX 480. Is it possible that my power supply is not giving enough power to the card? My power supply is the antec quattro 850watt, each +12V rail supply maximum 18A. I have two PCI-E plugged in so that supplies 36A maximum, which is 6 less than what Nvidia recommanded. I'm getting so frustrated with this stuttering problem. However there are couple of games i play that work fine: Starcraft 2 & GTA4. Can someone let me know if it is possible PSU is causing this?
PSU shoud be OK... U have 4 x 18A rails. nVidia might remommend 40A but its total for whole computer.. not just for GPU. Im running fine with 700W and 52A total (4x18A also)
PSU is more than adequate imo, and yeah like Mannerheim stated, the current (A) requirement is for the whole system, not just the GPU. Also i thought 850W TP has 25A for each 12?
Unfortunately, it only have 18A per rail, which is kind of low imo. Also the website you showed demonstrate 40A per rail, but mine is significantly lower than that. I'm switching the cable around and see if it does anything.
Your's has got an 18 amp per rail rating, the second revision upped the rating to 25a and actually has the setpoint at 40, not idea on where it's set on yours. Doesn't really matter, your card draws it's power from 3 of the 4 rails, each of the fixed PCIE connectors is on a seperate rail and the power to the slot is on another. I'm currently running my cpu at stock and SLI GTX460's on a 4 x 18a / 550w psu, somehow I don't think power is your issue.
except your gtx460s dont max out each rail. a gtx480 gets pretty power hungry. 18A is only 216w. so if somehow his gtx480 draws more than its rated tdp due to a factory overclock, then he'd be overdrawing from a rail. better to connect a 6pin from one rail and an 8pin from another rail.
If it's the PSU it's because it's not being consistent in it's output, and ripples. 4x18A Is more than enough for a GTX480, as it's 2x18 at least, which is quite a bit. Then the rest of the system is fed by another rail. But this has already been said. In fact I tried my ex-Thermaltake TP 750 with two 4870's and it fed them just fine and that has 4x18A. While it's not really comparable two 4870's at load consume more power than a single GTX480. Again it's not entirely an accurate comparison but it clarifies a little. What you could do is get another PSU and try that. You could also RMA the PSU and see whether that fixes anything. If it doesn't then it could be the video card or something else. Personally I thought this was logical. You have several cables for a reason. 2*18=36*12=432+75=not enough? While this is peak it's still more than enough for a 480, unless it starts going over 500W, which would be madness.
i think some older models have 18 amps. mine has 25 amps asswell per rail acording to antec antec tpq is capable off 64 amp combined. should be enough for gtx 480
40A is a requirement for the whole system. The card alone uses upto ~250W at stock clocks, that's about 21A. And you have 75W(6pin)6.25amps+150(8pin)12.5amps+300w(pcie2.0)25amps = ~43.75 amps available for the card alone. More than twice the power needed for a single GTX 480.
uhh, the pcie slot only supplies 75w. the 300w thing is a design specification that states that any card designed to run in a pcie2.0 port must not exceed 300w power draw. so its 75w from pcie slot + 75w from 6pin + 150w from 8pin. which means 300w max for the card. in the op's case, his each rail only has 18a, so that means itas more like 291w for a single card, which should be more than enough. not sure about the actual power draw of a gtx480 but a gtx 580's actual power draw according to guru3d was 280w, and the 480 drew more power than the 580 in their records so it may end up stressing the rail.
It only matters how much amps PSU has in total on +12v rails. Both pci-e power connectors and pci-e slot do not rely on only 1 rail, but 4 in his case, which is 72 amps , not 18. Of course single 6pin pci-e supplies 75W which is 6.25amps. 8pin 150W which is 12.5 amps And pci-e slot 75w which is 6.25 amps But yeah, 300W in total. ( mixed up this with something else wanted to post.. )
My pair of factory overclocked 460's pull as much or more power than a 480, and like the OP's single card, draw thier power from 3 of the 4 rails. What you've stated makes no sense.
