Power Supply Size.

[IcyIcy]

I'm in a bind. Building a new computer and I'm not sure how to calculate how large of a power supply I will need. I do not want to buy the biggest baddest power supply, would like to keep it to the requirements. I will list the components I am going to purchase. Any input no how many WATTS required would be helpful or power supply recommendations. Also would like verification on the pin numbers on the video card and how many connections one takes to power. Thanks in advance.


Intel Core 2 Quad Q9450 / 2.66 GHz 1333 MHz - LGA775 Socket - L2 12 MB ( 2 x 6MB )

GeForce 9800 GX2 1GB (one for now, another in the future, must have room for expansion to two)

EVGA nForce 790i Ultra SLI ATX Motherboard

1 Harddrive

1 CD/DVD Drive.

 

[calvary1980]

I would recommend the Corsair 620HX the Geforce 9800GX2 requires both 8-pin and 6-pin connections.

PS, Welcome to TPU.

- Christine

 

[IcyIcy]

It appears that one has only one 8 pin connector. Was planning to upgrade to another card eventually. Still not sure if 620W is enough for two of those cards.

 

[ShadowFold]

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006

or

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139007

They both should be good with dual 9800GX2's.

 

[calvary1980]

620 is fine for a 9800GX2.

- Christine

 

[mrw1986]

620hx can handle 2x 9800GX2

 

[ShadowFold]

You sure?.. thats cutting it kinda close imo..

 

[calvary1980]

I have this conversation too many times lol. 620HX was there flagship model but has been replaced by the 1000HX. if a 450VX can run these systems i'm sure the 620HX can run his. here is my favorite from that list.

Intel Core 2 Duo E8400 3.0 Ghz 45nm Wolfsdale Evga Nvidia 8800GT 512mb GIGABYTE GA-P35-DS3L Rev. 2.0 LGA775 Corsair DDR2 2 GB Ram 4-4-4-12 Coolermaster 690 Case Corsair 450VX PSU Samsung 500 GB Spinpoint hard drive Dual layer Dvd Burner Vista Ultimate

another guy was running a 9800GTX on a 450VX.

- Christine

 

[ShadowFold]

Thats three less cards tho..

 

[MKmods]

if you may run 2 of the 9800 X2s I recommend this (I use it) It has 66A on the 12V rail, 4 six pin PCI E cables and 2 of the 8pin ones
http://www.newegg.com/Product/Product.aspx?Item=N82E16817256036

(lol, I run a X2 4850e and 2 9600GTs, and 4 hdds on a 400watt)

 

[IcyIcy]

i'm sure the 620HX can run his.

1 x 20+4-pin ATX
1 x 4-pin +12V
1 x 8-pin EPS12V
2 x PCI-Express
10 x 4-pin peripheral
2 x 4-pin floppy
8 x SATA

This can only run 1 GX2 based on the connections. In the future I plan on to get a second, and upgrading power supply to do so is not cost efficient.

____

The 800W above looks like a reasonable choice, it does have the needed connections.

With that recommendation, I'm starting to lean towards the SilverStone ST1000, i'm a bit paranoid about these GX2's, I'm seeing several people running 1.2KW power supplies and I don't want to have power issues.

I've sent a question to nVidia requesting for power supplies capable of working with dual GX2's, hopefully they will reply by tomorrow, I'll post results here for future use.

 

[ShadowFold]

The Corsair 750w I linked is enough. The people with 1000w+ also have alot of HDD's which use alot of power as well, or they are nuts

 

[IcyIcy]

The Corsair 750w I linked is enough. The people with 1000w+ also have alot of HDD's which use alot of power as well, or they are nuts

These connectors are kind of confusing to me:
1 x Main connector (20+4Pin)
1 x 12V(4/8Pin) <--- This is a 1x 12V rail I believe
8 x peripheral
8 x SATA
2 x Floppy
4 x PCI-E

The 1 12V rail is the one that goes to the card I believe..., I would need two of these in the future.

I agree the 1000W will work as well. I'll just have to decide which of the two to select if I stick with 1000W.

 

[ShadowFold]

Corsair, Antec, Seasonic, Silverstone, Xigmatek, Thermaltake or PC Power and Cooling would be good choices. Seasonic makes Antec's, PCPAC, and Corsair's so they are really good.

 

[MrW]

I'd go with the 750W Corsair also.

 

[calvary1980]

ok I didn't see you wanted to run 2 of them. here forget Silverstone.

thats crazy if you have the money for that why not purchase the new Geforce GTX 280 it's coming out less than a month I believe.

- Christine

 

[MKmods]

forget Silverstone.- Christine

any reason in particular?

 

[calvary1980]

yea, 1000HX is essentially 2 500watt units on 1 PCB, 2 Chemicon Caps and 8 Heatsinks, Thermal Controlled Fan made by Yate Loon and I think it has 1 or 2 extra Cables. Silverstone uses a cheap ball bearing one that is noisy. sorry thats all I could think of

- Christine

 

[IcyIcy]

why not purchase the new Geforce GTX 280 it's coming out less than a month I believe.

I goggled it and found the 25th week of the year, or June 16th for this card release. I guess I'll be waiting to decide what to buy when the specs and price come out. Thank you for the heads up, didn't even think to research when the next series would be coming out.

 

[MKmods]

yea, 1000HX is essentially 2 500watt units on 1 PCB, 2 Chemicon Caps and 8 Heatsinks, Thermal Controlled Fan made by Yate Loon and I think it has 1 or 2 extra Cables. Silverstone uses a cheap ball bearing one that is noisy. sorry thats all I could think of

- Christine

LOL, well I have one and its pretty quiet to me, BUT if it starts making noise I promise to let you know you were right.

and to IcyIcy, the Corsair 1000 is a very good PS also. Better to err on the side of caution if there is a possibility of dual X2 cards and go with the 800 and up PS.

 

[mikek75]

IMO you are far better of going with a single 12v rail design, makes life a lot easier than trying to balance rails. I have the PC Power&Cooling Silencer Quad 750w which has a single 60A (continuous rating) rail. It has two 8pin and 2 6pin connectors and is certified for highend SLI and Crossfire.

 

[hat]

I agree with mike. Who wants to throw a bunch of rocks (many weak rails) when you have a nuke (one big rail)?

 

[IcyIcy]

Here is the Nvdia Responce:

Hello Stephen,

Thank you for contacting NVIDIA Customer Care.

This is Ganesh and I shall assist answer your query.

I understand that you would like to know the power supplies which support two GeForce 9800GX2 running in Quad SLI.

Two GeForce 9800GX2 cards require 850 watts to 1000 watts of power supply. Please click the link given below a compatible power supply.

http://www.thermaltake.com/product/Power/ToughPower/w0217/w0217.asp

Also, please click the link given below for more SLI certified power supplies.

http://www.slizone.com/object/slizone_build_psu.html

Please feel free to contact us for any further information.

Regards,
Ganesh,
NVIDIA Customer Care

 

[mikek75]

Yeah, maybe with a multirail PSU you would need 850-1000 watts of power as you will lose a percentage of each rail due to the fact that spare amps will be lost in underutilised rails. I'd be very surprised if the setup would draw over the 60A the PCP@C supplies. If it does then I really hope you don't have to pay the electricity bill, LOL

 

[poohball]

i will go with this...
http://www.newegg.com/Product/Product.aspx?Item=N82E16817815003

850W as cheap as 750W, don't miss this Xigmatek one, good stuff!