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Power requirements- 2x GTX460 SLI

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Anonymous
a b ) Power supply
September 21, 2011 5:08:52 PM

Hi,
I just read this months $1000 system builder article and noticed they use two gtx 460s in SLI and overclock the CPU, all on a Corsair CX600W PSU.

I have the same PSU (CX600) and one GTX460 and am looking to buy a second GTX460 to use in my system in SLI.

However I was sure I would need to buy a new, bigger PSU (at least 750W) for such a power hungry system, what do you think?
Many thanks in advance
Full system spec:
Spoiler
AMD X6 1090T @ 3.75Ghz (with H50 CPU cooler)
Corsair CX600 PSU
8GB RAM
One Gainward GTX460 1GB
1TB HDD (Spinpoint F3)
Asus SLI chipset mobo
a b ) Power supply
September 21, 2011 5:20:35 PM

I wouldn't do that with a 650w unit unless it was a really high quality unit but that wouldn't be $79. I have learned the hard way that some units tend to degrade if they are constantly maxed out at their full potential after a few months. 750w is better for a few reasons such the needs for the cpu and other system components. A single gtx 460 is 160w each at stock under full load (less than 750mhz samples) and a fully overclocked gtx 460 is around 200w a pop leaving only 200w for everything else. Most people have been buying those 125w and 140w cpu-s if amd and nuking intel cpus to where they suck just as much or a lot more power than that alone.
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Anonymous
a b ) Power supply
September 21, 2011 5:23:49 PM

Ubrales said:
Welcome to Tom's hardware Forums!

Just to be safe, I would go for a 750 watts Corsair PSU

This one is modular: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Much better cable management and air flow with modular PSUs.

Thank you for the advice, I was planning on buying a new PSU with a higher wattage, but the article I read this afternoon left me uncertain whether I needed a new PSU. The HX750 looks good- modular cabling is a massive help for me- at the moment the inside of my PC is a complete mess of cables :ouch: 
Anonymous
a b ) Power supply
September 21, 2011 5:26:40 PM

@nforce4max
Thanks for the reply- I'll do what you and Ubrales suggested and buy a good 750W unit.
September 21, 2011 5:29:37 PM

I have 2 460's and I went with a good 850W Thermaltake. 750 should cut it, but I'd rather be safe than sorry. Make sure that whatever you buy is 80Plus certified!
a b ) Power supply
September 21, 2011 5:33:41 PM

Be informed. Before you buy any PSU read accurate, objective PSU reviews at reputable sites such as www.jonnyguru.com or www.hardwaresecrets.com on the EXACT model PSU that you are interested in as some brands have good and poor quality PSUs.

You can also get an accurate rating of how much PSU power is required for your current or future system at the PSU calculator link below. Once you know the total PSU watts required then you need to confirm that the 12v rail has enough amps. to support your Vid card(s) and the rest of the PC system.

There are several websites that show the Vid card power consumption in watts. Divide the watts by 12 to determine the amps. required on the 12v rail(s). Add 15 amps for the rest of the PC on the 12v rail and you now know the Minimum total 12v rail amps required under full load. It's best to have at least 5-10 amps. reserve on the 12v rail available under full load so the PSU is not loaded to 100%.

It's also worth noting that people often misunderstand the 80% power rating. This is a rating of the PSU's energy efficiency not it's output. 80% plus PSUs use less grid power to produce the same PC power. If it's 80% Bronze, Silver or Gold the cost savings on electricity is pretty small between Bronze, Silver and Gold unless you are paying very high rates for electricity so any 80% rated quality PSU is fine even if not Gold. For those who leave their PC on 24/7 a quality 80% PSU is a good investment.

http://extreme.outervision.com/psucalculatorlite.jsp

http://www.guru3d.com/article/geforce-gtx-560-ti-sli-re...

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_5...
a c 87 ) Power supply
September 21, 2011 6:30:12 PM

Quote:
Thank you for the advice, I was planning on buying a new PSU with a higher wattage, but the article I read this afternoon left me uncertain whether I needed a new PSU. The HX750 looks good- modular cabling is a massive help for me- at the moment the inside of my PC is a complete mess of cables :ouch: 

If you can, wait for the Black Friday sale on November 25, 2011.

Check prices on the HX-750 as well as the HX-850 (both Corsair). Depending on inventory and promos, I won't be surprised if the HX-850 on sale is cheaper than the HX-750 on regular. I have the HX-850 and am very satisfied with it. It came in a velvet bag!
a b ) Power supply
September 21, 2011 9:40:19 PM

Cash091 said:
I have 2 460's and I went with a good 850W Thermaltake. 750 should cut it, but I'd rather be safe than sorry. Make sure that whatever you buy is 80Plus certified!


I wouldn't settle for just 80+, Silver or Gold is the way to go quality wise.
Anonymous
a b ) Power supply
September 22, 2011 6:47:34 PM

@beenthere
Thanks for the advice- very useful
I would never buy any PC component without first reading every review I could find on Google ;) 
@Ubrales
Will do- I'm happy to wait a couple of months if it means getting a good price.
@nforce4max
The HX750 is my first choice atm and it's pretty efficient (Silver)

Thanks again for all the help people, it's much appreciated.
!