Is this psu good enough?

[Medicteddy]

I was wondering if 700W would be enough to run my setup below? psu calculators seem to suggest that it will be, but I don't know how accurate these are...

My build:

i5 2500k overclocked to a maximum of 4.5GHz (don't want to risk pushing it further)
2 x HD6950 or 2 x 560ti's (planning on overclocking either setup)
1 HDD
4 x 4GB DDR3 RAM


This is the psu I'm planning on using:

Coolermaster Silent Pro 700W Modular PSU - Single 12V Rail with 50A

 

[king smp]

I would up the wattage a little
I would pick something in the 800 watt range
something like this one
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371024
the four companies you will see everybody recommend here is
Antec,Seasonic,XFX and Corsair
try looking those brands in the 8xx wattage area
just in case you add more powerfull GPUs later or more HDs you would have more room for expansion

 

[kajabla]

750W is enough. Make it a good one. http://www.guru3d.com/article/geforce-gtx-560-ti-sli-review/14
This one's great and efficient: http://www.newegg.com/Product/Product.aspx?Item=N82E16817207016

 

[ko888]

Get a power supply that actually has at least four PCI Express supplementary power connectors required for two Radeon HD 6950 in 2-way CrossFire mode or two GeForce GTX 560 Ti in 2-way SLI mode.

The Cooler Master Silent Pro M700 (RS-700-AMBA-D3) has only two (6+2)-pin PCI Express supplementary power connectors.

Since you're planning on overclocking get a power supply with more than 50 Amps on the +12V rail(s).

 

[kajabla]

The XFX has 4 PCIe plugs and 62A.

 

[Medicteddy]

how much does it matter that the psu is not modular?

 

[totalknowledge]

If it doesn't matter to you that its not modular, then it doesn't matter at all...

Cable management is easier, thereby making it easier to have good air flow, but in the end, its just a matter of taste.

 

[Medicteddy]

I think i'll spend a bit more to try and reduce cable clutter... these are the best priced modular psu's in the uk that i could find... could you help me choose?:

http://www.ebuyer.com/176413-coolermaster-silent-pro-850w-modular-psu-rs-850-ambaj3?utm_source=google&utm_medium=products

and

http://www.scan.co.uk/products/800w-psu-coolermaster-silent-pro-gold-80ga-d3-modular-90-eff-80-plus-gold-sli-crossfire-eps-12v-quie?utm_source=google+shopping&utm_medium=google+shopping

 

[kajabla]

It is modular. Its only non-modular attachments are the ones you will definitely be using: the motherboard, CPU and two PCIe cables. Everything else is detachable. It doesn't matter at all that it's not fully modular.
UK availability, £90: http://www.scan.co.uk/products/750w-xfx-xxx-p1-750b-ukb9-psu-88-eff-80-plus-silver-sli-crossfire-eps-12v-fan-atx-v22
http://xfxforce.com/en-us/Products/Power-Supply/XFX/Pro-Series/ProSeries-750W-PSU/750W-XXX-Edition-Semi-Modular-Silver.aspx

 

[Medicteddy]

oh ok! I must admit that i saw the cables and assumed that it was modular... didn't look close enough...!

How reliable are xfx as psu's? i've heard that antec, corsair and coolermaster were the ones to go for?

 

[Medicteddy]

It is modular. Its only non-modular attachments are the ones you will definitely be using: the motherboard, CPU and two PCIe cables. Everything else is detachable. It doesn't matter at all that it's not fully modular.
UK availability, £90: http://www.scan.co.uk/products/750w-xfx-xxx-p1-750b-ukb9-psu-88-eff-80-plus-silver-sli-crossfire-eps-12v-fan-atx-v22
http://xfxforce.com/en-us/Products/Power-Supply/XFX/Pro-Series/ProSeries-750W-PSU/750W-XXX-Edition-Semi-Modular-Silver.aspx

ahh i understand the mistake i made before - google image search was showing me the core edition of the power supply, which is modular, unlike the one you showed me

sorry for the misunderstanding!

 

[kajabla]

XFX is as good as any of the high-quality manufacturers. My short list at highish wattages (by quality, not price; some of these are expensive):
NZXT, Thortech, Corsair, Antec, OCZ, XFX, Silverstone
NZXT's HALE90 and Thortech's Thunderbolt are some of the best PSUs out there, but all of these are very good.

 

[Medicteddy]

Thanks for all your help mate - really helped me out with my dilemma!

Should I get the 750w or 850w version of the xfx xxx edition? £12 difference...

 

[kajabla]

You honestly don't need the 850W. http://www.tweaktown.com/reviews/3744/his_radeon_hd_6950_2gb_video_card_in_crossfire/index17.html

 

[king smp]

if the 12 pound difference is easy to afford than might as well go with the 850w
might not really need it but would be good to have the extra headroom especially doing SLI/CF
remember if you are using lets say 400w than with a 850w you are using less than %50 of wattage and the lower % of wattage used means greater efficiency
and if you ever decide to multiple HDs and Optical drives then it would help

 

[kajabla]

PSUs generally hit peak efficiency somewhere around 60%, so the 850W will be more efficient in gaming. You're right.

 

[Medicteddy]

So I should get the 850w if i can afford it?

Also, just to confirm - i know that 850w is the maximum continuous power, but does the psu draw less wattage under less load (i.e. everyday use)? just thinking about my electricity bill...

 

[ko888]

So I should get the 850w if i can afford it?

Also, just to confirm - i know that 850w is the maximum continuous power, but does the psu draw less wattage under less load (i.e. everyday use)? just thinking about my electricity bill...

The power supply only provides as much power as needed by the system. If the system is only demanding 300 Watts at the moment then that is what the power supply will provide. At the wall outlet the power consumption will be more than 300 Watts because of the conversion efficiency losses (e.g. 375 Watts for a PSU with 80% efficiency).

The power supply is not outputting a continuous 850 Watts all of the time.

Higher efficiency power supplies will use less electricity and generate less heat and therefore run cooler.

 

[Medicteddy]

The power supply only provides as much power as needed by the system. If the system is only demanding 300 Watts at the moment then that is what the power supply will provide. At the wall outlet the power consumption will be more than 300 Watts because of the conversion efficiency losses (e.g. 375 Watts for a PSU with 80% efficiency).

The power supply is not outputting a continuous 850 Watts all of the time.

Higher efficiency power supplies will use less electricity and generate less heat and therefore run cooler.

ahh ok thank you for clearing that up and for all your very helpful advice!