PSU requirement for video cards?

O

Overspeed

Limp Gawd
Joined
Feb 21, 2008
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I have a rig running the following hardware. I would like to add two dedicated AMD cards to it if my PSU will support it (currently running the integrated GPU). I have no idea what wattage my rig is using now. Details:

Asus p67
i7 2700K
256GB Crucial M4 SSD
8GB Corsair RAM
Corsair H100 cooler
3 1TB HHDs (usually idle)
3 case fans
1 Blu-ray player (usually idle)
Corsair AX650 PSU

Ideally, I would run a crossfire setup if I have enough power overhead left. How much wattage do you think this rig is using? Could I run dual 7950s? Better? Thoughts appreciated. Thx.

Edit: If my PSU is not sufficient to run two cards, what is the best single card I could install?
 
According to this website, total system draw is 617W, recommends 667W.

This is what I have for your setup assuming 30% capacitor aging:
https://dl.dropboxusercontent.com/u/589618/eXtreme Power Supply Calculator.pdf

I assumed three 92mm case fans.

Best case scenario, a 650W is barely enough and you might get by with it if you don't overclock. I'd recommend 700W or 750W just in case.

NOTE: THIS IS A COMPLETE APPROXIMATION AND NOT EXACT.

Other PSU calculators may show different values.
 
I checked the website you noted. It suggested I am using 350W currently. That would leave me 300W for a ??? video card. I'm not sure the website is correct however. I just remembered I have everything including a LED monitor plugged into a UPS. Using the front display, it says current system load is only 200W. That is the total of my rig, a 24" Dell VA monitor and Antec 2.1 channel speakers. This suggests to me I still have 450W to play with. Assuming this is correct, could I run dual 7950s? Or maybe a single R9280-X?
 
Sorry, but the PDF you are linking has no values in it.

Edit: actually I had to open it outside my browser to see the values. Thx.
 
they always shoot the number higher as many folks do not use very good power supplies to begin with. AX650 can handle a very high load but I can tell you my experience using dual 7870 on an HX750 that puppy got hot, so, are you sure you want to take the chance? think ~175w or so per card loaded +/- of course depending on which card.
14.58a a piece along with all the other things
cpu with full system average load would be ~220w or 18.34a
so if you put 2 cards plus your average system(and your is a bit above the average that other would have)
14.58+14.58+18.34=47.5a@12v=570w, so in theory you should be ok, but, you would be pushing that psu on its edge me thinks.

I know the AX850 you could pull ~1kw from it and it would run just fine, so I would assume with this it can deliver the full 650 no problems, but it is not my $.

Why not just opt for a single powerful card, say 7970GHe, 280x, 290 non x or whatever, they are not at all weak cards, I know for a fact you will have ample power for a single card of anything currently available and if you wanted to could overclock. The gpu alone would have to draw what 500w or the cpu 300+ the gpu to come close to this same level of power draw, I don't think that will happen with a single card, even most dual cards.

I do know of others that ran i7 980x and dual 7950(and GTX280) on the hx750, ax650 would be very similar capacity wise and they claimed to have run for 3+ years, so who knows.
 
According to Guru3D.com, a 550W PSU is sufficient for a R9-280X video card.
http://www.guru3d.com/articles_pages/radeon_r7_260x_r9_270x_280x_review_benchmarks,10.html

750W is recommended for CrossfireX.

Their test system is a bit higher end when tested the power draw measured at the wall outlet:
http://www.guru3d.com/articles_pages/radeon_r7_260x_r9_270x_280x_review_benchmarks,13.html

Power consumption AMD Radeon R9-280X

System in IDLE = 119W
System Wattage with GPU in FULL Stress = 350W
Difference (GPU load) = 231W
Add average IDLE wattage ~10W
Subjective obtained GPU power consumption = ~ 241 Watts
Click to expand...

So, in my best opinion:

Single 7950, or R9-280X - 550W bare minimum to 650W recommended

Dual 7950, or dual R9-280X - 750W recommended
 
Ok, maybe i'll put a little $ into a new PSU. My AX650 is modular ... meaning I can add or remove power lines right at the unit. I would prefer not to have to re-wire my system. On that note, I might consider a higher wattage Corsair AX series PSU. I'm hoping I can just swap out the PSU and the current wiring I have in place will plug into the new unit. Of course the connectors will have to match etc. Can anyone verify this?
 
Overspeed said:
Ok, maybe i'll put a little $ into a new PSU. My AX650 is modular ... meaning I can add or remove power lines right at the unit. I would prefer not to have to re-wire my system. On that note, I might consider a higher wattage Corsair AX series PSU. I'm hoping I can just swap out the PSU and the current wiring I have in place will plug into the new unit. Of course the connectors will have to match etc. Can anyone verify this?
Click to expand...

This is from Corsair:
http://www.corsair.com/en/media/cms/manual/PSU_Sleeved_Compatibility_Matrix2.pdf

The modular cables on the AX650 are compatible with the AX750 and AX850, and that is it.
 
Overspeed said:
Damn, I can't find any AX750s or AX850s anywhere. Seems they're discontinued.
Click to expand...
Yup, the AX750 and AX850 were replaced by the AX760 and AX860.

So it looks like you're looking at redoing the wiring in your PC as well.
 
I have never tried used PSUs before, but you are taking a risk:
http://www.amazon.com/gp/offer-list...l?ie=UTF8&colid=&coliid=&me=&qid=&seller=&sr=

$149.99 for a used AX850. I'd just go for a brand new AX760 or AX860, honestly.

The AX760 can be had for the same price as a used AX850:
http://www.amazon.com/Corsair-Profe...&qid=1385652574&sr=1-1&keywords=Corsair+AX750

Newegg can get you $129.99 after mail-in rebate for Black Friday:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139042

The AX860 for $169:
http://www.amazon.com/dp/B00A0HZMKG/?tag=extension-kb-20

Newegg has it for $149.99 after mail-in rebate:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139044

If want to go lower and stick to Corsair, the TX750 can be had for $79.99 ($59.99 after $20 rebate for Black Friday):
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006

But, if you want modular, middle of the road, there's the HX750:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010
 
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single 7950-7970-R9-280x-290-290x like I stated any single current card, 650 are fine.

I would take the AX650 over the TX750, one is built using overspec components(AX) the other with decent components(HX)

new AX should be compatible connector wise, no?

HX750 can handle it I know this as I have one, but am telling you, it would get very hot, I think in this case the AX650 might still be the better choice and would work fine, as long as you don't overclock or at least very slight, if it can handle dual 7950/gtx280-i7 950 in an overclocked state then it can handle yours without one.

what resolution are you using BTW, R9-280x or R9-290 probably be ample without the need of screwing with CF/SLI
 
dragonstongue said:
single 7950-7970-R9-280x-290-290x like I stated any single current card, 650 are fine.

I would take the AX650 over the TX750, one is built using overspec components(AX) the other with decent components(HX)

new AX should be compatible connector wise, no?

HX750 can handle it I know this as I have one, but am telling you, it would get very hot, I think in this case the AX650 might still be the better choice and would work fine, as long as you don't overclock or at least very slight, if it can handle dual 7950/gtx280-i7 950 in an overclocked state then it can handle yours without one.

what resolution are you using BTW, R9-280x or R9-290 probably be ample without the need of screwing with CF/SLI
Click to expand...

According to Corsair's cable compatibility list:
http://www.corsair.com/en/media/cms/manual/PSU_Sleeved_Compatibility_Matrix2.pdf

The AX650, 750 and 850 are not compatible with the AX760 and AX860 PSUs. ><;

He'll have to get a new power supply regardless, but yeah, his current 650W should be more than enough for a single card and his current setup.
 
dragonstongue said:
what resolution are you using BTW, R9-280x or R9-290 probably be ample without the need of screwing with CF/SLI
Click to expand...

My monitor is 1920x1200. I just found a lightly used AX850 on Kijiji for $75. I'll get that and run two GPUs. One GPU will be for everyday use and the other will be a dedicated miner.
 
scrypt mining I assume? I hope you have a good 2 slot room for ventilation or its gonna get hot, I would also change the thermal paste on them if you have some like MX4 or something it helps quite a bit.

Sucks they are not compatible :(

1920x1200, I would maybe go for mixed cards i.e 1 big such as 280x or even a 290 for the mining and the other whatever for gaming, 7870 or better is perfectly ample for 1920x1200.
 
dragonstongue said:
1920x1200, I would maybe go for mixed cards i.e 1 big such as 280x or even a 290 for the mining and the other whatever for gaming, 7870 or better is perfectly ample for 1920x1200.
Click to expand...

Yes, LTC mining. I had assumed both cards needed to be the same to enable crossfire. For mining they don't need to be attached? (crossfire cable)
 
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