Wikipedia:Reference desk/Archives/Computing/2013 October 6

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October 6

Graphics cards: Wattage and comparison

My friend and I have been Googling this for 20 minutes but apparently we're not allowed to know the exact wattage of my graphics card. While searching, we did some across some information, so we're just going to make some assumptions and go from there:

My card is an Nvidia GT430 (one of them...apparently there's more than one version...). It plugs directly into the motherboard and doesn't have a dedicated power socket. So based on things I've seen online, that means it can only draw a limited amount of power. The assumption I want to make here is that any other card which also doesn't plug into power directly will also draw the same amount of power, so any such card would be a compatible switch-out for my current card (barring other compatibility issues, which we think we've got covered - this is the only sticking point).

Is this safe to assume? 86.181.64.123 (talk) 08:22, 6 October 2013 (UTC)

The most a PCI-Express card can draw from the motherboard socket is 25W (for PCI×4 and PCI×8) or 75W (for PCI×16) per PCI Express#Power. NVIDIA's spec for that chip is here which says it's PCI×16), and that its max system power requirement is 300 W. It's up to the OEM making the card which contains the GeForce chip whether they put an additional power connector on it or not. -- Finlay McWalterჷTalk 08:42, 6 October 2013 (UTC)

About your last statement, generally speaking, it's not that common. The OEM doesn't have much choice because few OEMs want to add one when it isn't needed (which will not only limit the pool of people who can use it but is also pointless) yet few or no OEMs are dumb enough to not add a connector if the card draws 100W (or something). While OEMs do have some customisation ability including clocking the various chips clocks or memory higher, and the amount and sometimes type of memory, and very occasionally bus width, and of course the type therefore efficiency of power supplies components on the card; these are usually not enough to change the requirement or non requirement for a power connector as few cards are that close to the borderline. There are some exceptions e.g. 6750 which used about 70W-90W so could be below the maximum and came in versions with and without the connector [1] [2] [3].

BTW in case it isn't clear to the OP, few or no vendors make video cards which are not PCI×16 (at least not for desktops, I don't know about laptops) probably because there's little point as it's very rarely an issue as PCI×16 is the defacto standard for video cards even if it's questionable if it's always needed so it must be exceedingly rare someone would have need for a video card yet lack a PCI×16 slot (some people may use a video card in a 16x slot with 8x or fewer lanes connected).

A final point in case it isn't clear, a card without a power connector can draw up to 75W, the precise consumption will vary significantly depending on the card, from the 6750s which I'm guessing were resonably close to 75W to probably 10-20W. Per the source, the GT430 was 49W according to Nvidia. Of course the precise power draw will depend on your specific card and it's actually fairly common OEMs don't publish good figures. The power system requirement published by Nvidia and AMD or for that matter OEMs are actually IMO fairly useless. They make assumptions which may not hold and not surprisingly are usually quite conservative probably partially because a large number of people still by POS power supplies which cannot actually supply what they claim (or can only do so under completely unrealistic conditions).

Since IIRC you live in the US and can use NewEgg and you also seemed to be using standard components, it's IMO worth considering whether it's worth worrying so much about keeping your current power supply which if it can't even support a 6 pin PCI express card in you system (which I'm assuming is not a dual CPU 6 core or something) is not likely very good (there are a small number of PSUs which are good yet may fall in to that category but they aren't common) as a decent power supply which would likely support a least most or all 6 pin PCI express power connector cards and hopefully is not going to take out your whole system as your current PSU may no matter what card you use, will likely be under $70 and from your comments it sounds like you're looking to spend at least that for the card. (We're obviously not talking about a 8+6 pin card although realisticly a PSU to support a single card like that won't be that much more.) I'm presuming of course power is the main concern and not thermals as it seemed to be what you were concentrating on.

I'm not of course suggesting this is necessary, it sounds to me like you'll be happy with something like a HD 7750 which doesn't need a 6 pin PCI expres connector but if you do want something else it's worth considering why you're limiting yourself. Definitely it would seem this makes sense if your PSU can't definitely support any card without a PCI express connector.

Nil Einne (talk) 12:43, 6 October 2013 (UTC)

I found this discussion of a 430's power consumption pretty quickly... for a card that doesn't have an extra 5v plug in, 80W seems really high. And keep in mind, unless you're doing something that is taxing the graphics card, it will run at idle which (and i'm guessing here) is probably more in the 15-20W range. It's also worth considering that your setup won't draw more than your PSU will allow, wattage wise. Shadowjams (talk) 20:05, 6 October 2013 (UTC)

Thank you for the responses, everyone; very helpful, much appreciated. Nil Einne, the reason I'm limiting myself is because I don't watch to change my PSU because I don't like doing anything like this, and am only really changing the graphics card because I feel I have to. The PSU can almost certainly support anything in a PCIE slot just fine, but I wanted to play safe and make sure. There's also a degree of unfamiliarity with cards with extra pins to connect, and yeah, you might scoff at that and say it's just one simple tiny extra thing, but it's a simple tiny extra thing that I know nothing about and haven't experienced, and I'm not going to take the chance of me missing one tiny key detail with regards to this one tiny little thing and having opened up my comptuer and removed my old card only to find that I need to put everything back again just to reboot and Google what my problem is.

The HD 7750 does seem like it is pretty much what I'm looking for, and with that setting the bar, so to speak, I think I'll be happy to look around a little more with my friend and settle on a card, thanks to all of the help given here. So thanks again, everyone. 86.181.64.123 (talk) 13:04, 7 October 2013 (UTC)

(Oh, and for reference, I live in England. If I've ever linked Newegg for examples before it's because my American friend uses it. No idea if Newegg supplies in England, don't know much about them...) 86.181.64.123 (talk) 13:06, 7 October 2013 (UTC)