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PSU for 6990 (+ potential 6950)

sportbilly

sportbilly

sportbilly

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Joined
1 Feb 2009
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80
I have a quote for a system from OcUK valid from Tuesday for 7 days. Based on Titan Mosasaur but added :-

HIS 6990 (with 4 games) at the offer price
Vertex 3 120gb again at offer price last week
WD Black 1TB instead of Seagate 1TB drive.

The system comes with a OCZ Stealthstream 2 700W which cost £61.

I will be running triple screens eyefinity at 5760x1080 and may well add a further 6950 if I feel that it struggles a little at that resolution in the future.

So I would like to upgrade the PSU to give me the necessary headroom. I don't want to spend a fortune of the PSU upgrade but on the other hand I don't want to have a PSU costing £61 which would then not be up to the job if / when I decide to add the 6950 - might as well spend the extra £50 or so now.

So I was looking at the PC Power and Cooling 910w PSU which would cost around £50 more. Looking at reviews it is a very solid PSU but not that quiet and not modular if that matters.

I'm not too worried about the noise - let's face it the 6990 will not be the quietest and I game with a headset anyway but if I can should avoid adding too much more heat and noise if possible.

Another option would be the Coolermaster Silent Pro Modular 1000w for £125 or the OCZ ZX Series 1000W '80 Plus Gold Certified' Modular Power Supply looks really nice but is £150 and not due to 16th May.

So how much juice do I need and what is the best value solution for ?

Cheers
 
I know what the consumption figures are i have 6990 + 6970 and under load the power draw will be 800 watts plus so no way would i recommend a 900 watt psu to run those cards as it would be balls to the wall if it could run the pc at all.

Throw in extra fans hard drives maybe water cooling and you soon start pushing 1000 watts.

To spend £800 on cards then use that cheap insufficient psu would not be very wise.
 
johny dolan said:
I know what the consumption figures are i have 6990 + 6970 and under load the power draw will be 800 watts plus so no way would i recommend a 900 watt psu to run those cards as it would be balls to the wall if it could run the pc at all.

Throw in extra fans hard drives maybe water cooling and you soon start pushing 1000 watts.

To spend £800 on cards then use that cheap insufficient psu would not be very wise.
Click to expand...

Well, the test on the 6990+6970 was performed with a Intel 920 overclocked, an MSI X58 board, 6 GB of Corsair Dominator RAM and a Western Digital 640GB Black... and the load comes from Furmark which will never be like that.
 
If money is tight Buy the corsair 1200 psu and a single 6990 then add a 6970 later when funds allow or even a 6970 and the corsair then add the 6990 latter but if your plans are to end up with tri fire 6 series you need a 1000 watt psu that 900 will not be man enough imo.

When the power draw is 800 watts plus its crazy to buy a 900 watt psu to save a few quid it will fail and when it does it could take the rest of the pc with it.

Work out what power you need then add a couple of hundred extra for head room.

The ati cards will throttle back in Furmark so you dont see the true max draw from that system trust me it will use 800 to 850 watts on peaks so to just have 50 watts head room to save a few £ is very unwise and will end in tears.
 
Really best if it's an Ocuk sold item - the system can then be wired up / installed and tested.

Thanks the tri-fire figures at Hardocp - that seems to indicate 800w+ and that was not overclocked I don't think. Allowing for 85-90% efficiency a 900w Psu would be pushing it even a 1000w is getting close after overclocking.

The OCZ 1000w at 90%+ effeciency looks the favourite at the moment - not due until 16th May and almost another £100.

Cheers
 
sportbilly said:
Really best if it's an Ocuk sold item - the system can then be wired up / installed and tested.

Thanks the tri-fire figures at Hardocp - that seems to indicate 800w+ and that was not overclocked I don't think. Allowing for 85-90% efficiency a 900w Psu would be pushing it even a 1000w is getting close after overclocking.

The OCZ 1000w at 90%+ effeciency looks the favourite at the moment - not due until 16th May and almost another £100.

Cheers
Click to expand...

It was overclocked.

Best unit you can buy is the Corsair AX1200. Much better than the OCZ.
 
Going by those numbers quoted in the [H] review above (yes they are running 3DMark or whatever but if you run that type of hardware your most like going to be benching it using this type of software so you will need a PSU that up to the task) I personally wouldn't be looking at any PSU that draws anything less the 4 digits as I just don't like the idea of my PSU being pushed to close to it's limit and ideally you want to be running at 50% to 75% max load for optimum efficiency.
 
I'd also go for 1000w minimum with that much horsepower.

It might not be necessary, but it would sure as hell make me feel better :D
 
Ezyryder said:
It was overclocked.

Best unit you can buy is the Corsair AX1200. Much better than the OCZ.
Click to expand...

The CPU ([email protected]) was overclocked but not the GPU - taken from the first page "Note that the Radeon HD 6990 is running in its default stock BIOS operation, meaning the GPUs are running at 830MHz. Therefore the Radeon HD 6970 is also running at 830MHz, and the subsequent down-clocked memory speeds along with he Radeon HD 6990."

Yet it still pulled 811W in tri-fire.

On another test of the 6990 alone - when overclocked to 935/5.6 the system pulled 689W.

Would then need to add on the power consumption for a 6950/6970 potentially overclocked of 200w+.

So would be getting on just short of 900w as a maximum. So a 1000W is pushing it a little too.

Maybe I will just stick with the standard PSU and then upgrade if I decide to add the 6950/70 later - starting to get a bit expensive for a "just in case" scenario.

However, the standard 700W PSU now looks inadequate anyway looking at the overclocked 6990 figures of 689W.

My system would be an overclocked I7-2600K to 4.6+ instead of an [email protected] if that affects power much ?

Ideally want the PSU to to under £150 given that the upgrade will then cost £89 (existing PSU cost £61) but could be pushed to the OCZ ZX Series 1250W '80 Plus Gold Certified' Modular Power Supply - Gold rated 92% 1250W for around £55 less than the Corsair AX1200 making the upgrade cost £109 rather than £164 :eek:

Edit - Decent review here for the OCZ 1250W - ran at 1350W before shutdown at 1367W.

Back to the drawing board.

Cheers
 
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I do run 6990 + 6970 a 2600k @ 4.5 and water cooling with my 1000 watt psu that's why i said 1000 minimum but my next upgrade will be a larger psu as ive had this current one for 5 years now.

So what your thinking of buying will run on a 1000 watter for sure buts its always good to have a few hundred extra in reserve and that 900 watter would be balls to the wall.

This is what id reccomend still a little over budget but if you cant afford the 1200 watter then this is as low as id go

http://www.overclockers.co.uk/showproduct.php?prodid=CA-012-CS&groupid=701&catid=123&subcat=1084

any less of a psu would be a risk imo.
 
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