How many Watt need for 4870X2 ??

[rickyslc]

How many Watt need for 4870X2 ??

did 650 watt enough??

the system is like:
AMD Phenom 9950
asus M3N-H/HDMI A780 motherBroad
2 G RAM 1066
HD 4870X2



Thank You!!

 

[rickyslc]

if i use 750Watt will it do better performance v the HD4870X2??

 

[mactronix]

This is what it says on the sapphire product page,

System Requirements

–PCI ExpressR based PC is required with one X16 lane graphics slot available on the motherboard

–650 Watt or greater power supply with one 2x3-pin PCIeR power connector and one 2x4-pin PCIeR power connector is required (1K Watt with two 2x3-pin and two 2x4-pin connectors for ATI CrossFireX™ technology in dual mode)1

–Certified power supplies are recommended. Refer to http://ati.amd.com/certifiedPSUfor a list of Certified products

–Minimum 1GB of system memory

–Installation software requires CD-ROM drive

–DVD playback requires DVD drive

–Blu-ray™ / HD DVD playback requires Blu-ray / HD DVD drive

–For a complete ATI CrossFireX™ system, a second ATI Radeon™ HD 4870 X2 graphics card, an ATI CrossFireX Ready motherboard and one ATI CrossFireX Bridge Interconnect cable per graphics card (included) are required

Personally i would go with the 750 Watt unit, Make sure you get a good make/brand.
Mactronix

 

[spaztic7]

A eleventeen baquilliono watt power supply!

I would not use a 750w psu. Remember, it may need 750w but a 750w psu wont give you 750w. What is the efficiency of the psu? Calculate that into the amount and you will see how much the psu really gives.


So a 1000w that has an 85% efficiency (very high) give you a snug 850w at full load.

I hopes I'm right about this. Correct me if I am wrong.

 

[mactronix]

Nope you are wrong. (well you did say to tell you)

They always way over exagerate these specs and they say 650 for single card and 1000 for two.
This PSU would power it http://www.newegg.com/Product/Product.aspx?Item=N82E16817371015 even though its a 650 unit its a good one and i only said 750 to be on the safe side as we wasn't talking specific models and wanted the OP to be on the safe side.
Here is a list of certified PSU's for use with the X2 http://game.amd.com/us-en/crossfirex_components.aspx?p=3#ATI%20Radeon™%20HD%204870%20X2

Mactronix

 

[Shadow703793]

^+1. That PSU will power it, but I prefer a Corsair. The 650TX is only $10 more and it has a bit more rail stability than the Antec (if I remember correctly).

 

[mactronix]

Yea i saw the corsair but I am not too sure how things sit with a single rail , even one as awsome as that one
I did like the 450 for my last build but went for dual rail in the end. There probably isnt much in it though.

Mactronix

 

[spaztic7]

Ok, thats fine. The only other thing I would make sure of is that it has all the right plugs for it. I did see that ATi recommends a 750w for the 4870x2.

 

[ik694]

I have the 4870x2 and an Antec 650 Neo Power, works fine, never had a issue. If you do get it and do the fan fix, i would suggest somewhere around 50% fan speed, I had mine at 75% and it got a little annoying Playing HL

 

[rickyslc]

ThANK you u all answer my question.. i will buying 750W coolermaster power supply

 

[Shadow703793]

^WOW! FAIL! You still don't get it do you? Get a Corsair or a PC Power & Cooling. The CoolerMaster PSUs are cr@p.

 

[Kari]

So a 1000w that has an 85% efficiency (very high) give you a snug 850w at full load.

I just wanted to clarify this...
The 1kW PSU will very likely give all of the marketed 1000W to the system but it will draw more from the outlet. @85% it will draw something like 1180W from the grid

 

[spaztic7]

I just wanted to clarify this...
The 1kW PSU will very likely give all of the marketed 1000W to the system but it will draw more from the outlet. @85% it will draw something like 1180W from the grid

Really? I am intrigued. I can't wrap my head around that. Could you explain this a little more for me.

Where I am getting stuck at is that a 1000w PSU should produce 1000w. Is this 1000w from the wall or it gives you 1000w to use? I am currently under the assumption that it draws 1000w from the wall and gives you less to use.

 

[Kari]

It'll produce 1000W of usefull electricity for the system to use and since it's not an ideal component it'll draw more from the wall. The 'excess' is wasted as heat in the transformation process.

If it was the other way around, it would severely complicate rating/marketing of the unit as the efficiency of the unit varies under different loading conditions and typically is lower at the extreme ends of the range (at very low and very high loads). So you wouldn't really know what kind of output you would get with different units.

see anandtechs PSU articles for those efficiency curves, for example these
http://www.anandtech.com/casecoolingpsus/showdoc.aspx?i=3270&p=13

 

[Kari]

and the "The 1kW PSU will very likely give all of the marketed 1000W to the system " was there just because not every el-cheapo-psu can really give you what the marketing team promises.

 

[Kari]

and in case you're wondering about those curves, anandtech tests psus all the way to 110% of the rated capacity, so that 625W unit is tested all the way to 685W load

 

[WR2]

^WOW! FAIL! You still don't get it do you? Get a Corsair or a PC Power & Cooling. The CoolerMaster PSUs are cr@p.

Actually he's picked a good 750W PSU - nothing wrong with the Coolermaster Real Power Pro 750
Another CM 750 review

 

[WR2]

Where I am getting stuck at is that a 1000w PSU should produce 1000w. Is this 1000w from the wall or it gives you 1000w to use?

PSU are rated by output power in DC watts - it's what is available to power the PC components.
AC input (the wall socket) and DC output (power to the PC).

 

[Shadow703793]

Still for a few $ more you can get a Corsair or a PC Power & Cooling. Also worth noting is that those reviews didn't even come close the the demand of the [H] testings.

 

[spaztic7]

Thank you all for the explanation. My confused mind has now been calmed.


For whatever the reason I though you took the 85% efficient off what the sticker said the PSU wattage is.


Thanks for clearing it up.

 

[WR2]

Still for a few $ more you can get a Corsair or a PC Power & Cooling. Also worth noting is that those reviews didn't even come close the the demand of the [H] testings.

How did HardOCP rate the Coolermaster Real Power Pro 750??

 

[Shadow703793]

^I don't believe they have a review for it. But what I was saying was [H] testing is much more intense.

 

[WR2]

Actually they do have a review of that PSU.

 

[Shadow703793]

^Really? I guess I missed it then. Mind posting it for me?

 

[WR2]

Probably not worth your time reading - if like you said - "CoolerMaster PSUs are cr@p"

Still HardOCP seemed to be toying with the idea of giving it the same award they gave the Corsair 750TX.
Which is a bit odd since I don't think you wanted to give the OP a recommendation for a cr@p PSU.