To upgrade or not to upgrade the PSU

[Bacms]

Hello everyone,

Recently I got a new motherboard and new graphic card for my system so the current configuration is as follow:

Core 2 Quad Q6600 (stock)
Asus Maximus formula (x38)
ATI Radeon 4870x2
4xDDR2 2GB
4xSATA Hard drive

The problem I have at the moment is that on the manual of the board is referred that the board should only be used with a 8pin cpu 12V connector but the PSU only as a 4pin connector.

Do I need to upgrade the PSU because of this? And if yes, I am looking to something in the range of 850W specially because selling the 4870x2 and install 2x6950 is on my plans, which PSU should I pick I have been looking into the BeQuiet P9 but could not find any decent review of this PSU.

 

[davcon]

I doubt you'd need an 850W psu.
A good 650W would do the job.
A 750W would give you piece of mind.
XFX P1-650X-NLG9 XXX 650W Modular - £71.96 Inc VAT
http://www.scan.co.uk/products/650w-xfx-xxx-edition-modular-80-plus-bronze-85-eff-sli-crossfire-eps-12v-135mm-fan
Antec True Power New 650W Modular Power Supply PSU 80Plus Bronze SLi-£69.56 Inc VAT
http://www.scan.co.uk/products/650w-antec-truepower-new-modular-80-plus-bronze-82-eff-sli-crossfire-eps-12v-120mm-fan
XFX Pro 750W Core Edition PSU - £73.38inc. vat
http://www.ebuyer.com/product/241552

I recently changed out a mobo the old one was 4pin and the new one 8pin.
It would not power up with the 4pin luckily my psu had both connectors 8 and 4.
Powered up right away once the 8pin connector was plugged in.

 

[Bacms]

The main reason I am looking into 850W is to be future proof.

I know that the 650W will probably do the job now but according to the PSU calculators I have used I need something in the range of 750W for a crossfire configuration using the AMD HD6950. Hence isn't it safe if I just upgrade to an 850W instead of using a 750W and then need to upgrade again in the future?

 

[davcon]

The main reason I am looking into 850W is to be future proof.

I know that the 650W will probably do the job now but according to the PSU calculators I have used I need something in the range of 750W for a crossfire configuration using the AMD HD6950. Hence isn't it safe if I just upgrade to an 850W instead of using a 750W and then need to upgrade again in the future?

http://www.guru3d.com/article/radeon-hd-6950-crossfirex-review/14
Most components and newer tech is much more power efficient then previous gens.
Also high quality psu's deliver more then their rated power.
For instance my Corsair HX750 is capable of supplying over 900W.
You would be more then fine with a good 750W unit like the XFX i linked.

 

[Bacms]

Thank you very much for your answer.

A second card requires you to add another ~160 Watts. You need a 650+ Watt power supply unit and if you use it in a high-end system a 800+ to a KiloWatt is recommended especially if you plan on any overclocking

This is my concern...since the reason for changing board was actually to OC the processor.
I was also looking to the higher segment of the PSU market, modular and high efficiency is something I would be inserted in having even with the increased price tag.

Here is the list I was looking into:
Corsair AX850 £153.90
Corsair AX750 £127.38

BeQuiet Dark Power Pro P9 850W 167.48
BeQuiet Dark Power Pro P9 750W £129.56

Antec 850W High Current Pro PSU £143.40
Antec 750W High Current Pro PSU £153.18

Any reason for the Antec and BeQuiet not being in your list?

 

[davcon]

Thank you very much for your answer.

A second card requires you to add another ~160 Watts. You need a 650+ Watt power supply unit and if you use it in a high-end system a 800+ to a KiloWatt is recommended especially if you plan on any overclocking

This is my concern...since the reason for changing board was actually to OC the processor.
I was also looking to the higher segment of the PSU market, modular and high efficiency is something I would be inserted in having even with the increased price tag.

Here is the list I was looking into:
Corsair AX850 £153.90
Corsair AX750 £127.38

BeQuiet Dark Power Pro P9 850W 167.48
BeQuiet Dark Power Pro P9 750W £129.56

Antec 850W High Current Pro PSU £143.40
Antec 750W High Current Pro PSU £153.18

Any reason for the Antec and BeQuiet not being in your list?

These units are very high quality and priced well.
Corsair HX Series 850W Modular - £128.39 inc. VAT
http://www.aria.co.uk/Products/Components/Power+Supplies/Modular+700-950W/Corsair+HX+Series+850W+Modular+ATX2.2+SLI%2FCrossfire+Compliant+Power+Supply+?productId=36020
XFX P1-850B-NLG9 Black Edition 850W Modular-£113.51 Inc VAT
http://www.scan.co.uk/products/850w-xfx-black-edition-modular-80-plus-silver-88-eff-sli-crossfire-eps-12v-135mm-quiet-fan
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=153
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=165