Absolute minimum power needed for 2x 4870 512mb

reznik · 02-26-09, 03:49 AM

Greetz, i recently purchased a new monitor ( Asus VH226H 22) and fantastic one at that. I run it at its max rez 1920x1080 and can still play most games maxed out and at good FPS with a single ATI 4870 512mb.

I've decided to fill the 2nd slot in and CF the system, going to buy another identical 4870 512 board since the price is right atm.

Question is would my current ; OCZ game X stream 600W PSU, power the 2 cards...^^ and if not what minimum supply would i have to buy to get away with powering the two...i really dont want to spend a great deal at all on a power supply.

chevro1et · 02-26-09, 04:30 AM

Guru3d measured 480 watts peak usage with a 4870 crossfire setup. Given that your 600w psu is ~80% efficient, that makes exactly 480w. I would be looking for something in the 700-750w range with high amps on the 12v rail(s) for rock-solid stability... maybe something like the Corsair 750TX.

reznik · 02-26-09, 04:53 AM

hmm what exactly does that mean...the 600w Xtreme psu could support both cards??...i mean for example if i went ahead and bought the card...tried a CF setup...and see if it worked...if not..then id buy the new PSU after??

..totally random..but a 3.2 ghz quad wouldn't bottleneck a cf setup would it?

prime81 · 02-26-09, 05:04 AM

If your overclocking and crossfiring, he meant go for a higher PSU. Sure it may work, but it'll either be unstable or you'll blow your PSU.

Rick James · 02-26-09, 05:10 AM

I just picked up a 850W Raidmax on newegg for 100 bucks. Even has modular cables. Is awesome

Rich'[ard] · 02-26-09, 05:40 AM

it'll keep randomly restarting ^^ go for a 750/850W Corsair. they're rock stable.

reznik · 02-26-09, 05:44 AM

Okay okay you guys are defo right..*sigh problem is prices for powersupplies in uk are ridiculous..im not comfortable spending that much on a ps..750+ wattage

Quote:

Originally Posted by Rick James

I just picked up a 850W Raidmax on newegg for 100 bucks. Even has modular cables. Is awesome

and how on earth did u manage that...too bad over hear were affected by our weakening currency since everything is imported..

750 i think should do it..iv seen otherse use them comfortabley for CF...

mattgmann · 02-26-09, 07:52 AM

If you have to buy one or the other, buy a power supply, and upgrade your video card later. Why does everybody whine about buying power supplies? It should be the first and most important component you pick out for your system.

If you want to run an OC'd quad and 2 4870s, you need a GOOD 750W unit or better. Corsair is popular and reliable. Thought the 750tx isn't really that great of a performer, tons of people have it and swear buy it. Antec, PC power and cooling, BFG, Seasonic; these are all pretty reliable brands. Other brands you really need to research the individual model of the psu before buying. (i.e. raidmax. don't buy a raidmax, they're cheap and ****ty...you get what you pay for)

Hardin · 02-26-09, 09:00 AM

80% efficiency doesn't mean that it's only going to give you 480w. It means it's giving you the full 600w, but it's drawing more power in the form of heat to give you that power. http://www.silentpcreview.com/article28-page2.html
http://forums.anandtech.com/messagev...&enterthread=y

02-26-09, 03:49 AM	Thread Starter #1
reznik Member Join Date: Jun 2008 Location: Somewhere in the UK	Absolute minimum power needed for 2x 4870 512mb Greetz, i recently purchased a new monitor ( Asus VH226H 22) and fantastic one at that. I run it at its max rez 1920x1080 and can still play most games maxed out and at good FPS with a single ATI 4870 512mb. I've decided to fill the 2nd slot in and CF the system, going to buy another identical 4870 512 board since the price is right atm. Question is would my current ; OCZ game X stream 600W PSU, power the 2 cards...^^ and if not what minimum supply would i have to buy to get away with powering the two...i really dont want to spend a great deal at all on a power supply.
	QUOTE Thanks

02-26-09, 04:30 AM	#2
chevro1et Member Join Date: Nov 2005 Location: 35.012N/ 129.052E	Guru3d measured 480 watts peak usage with a 4870 crossfire setup. Given that your 600w psu is ~80% efficient, that makes exactly 480w. I would be looking for something in the 700-750w range with high amps on the 12v rail(s) for rock-solid stability... maybe something like the Corsair 750TX. __________________ Dell Inspiron 640m Intel C2D T5500 Centrino (1.66 ghz/ 667 fsb) 2x1 gig RAM (533 fsb) WD Scorpio Blue 500gb hdd Intel 950GMA integrated graphics 14.1" widescreen (1440x900) w. Truebrite Vista Home Premium 5in1 card reader/ Bluetooth/ 3945abg wireless
	QUOTE Thanks

02-26-09, 04:53 AM	Thread Starter #3
reznik Member Join Date: Jun 2008 Location: Somewhere in the UK	hmm what exactly does that mean...the 600w Xtreme psu could support both cards??...i mean for example if i went ahead and bought the card...tried a CF setup...and see if it worked...if not..then id buy the new PSU after?? ..totally random..but a 3.2 ghz quad wouldn't bottleneck a cf setup would it?
	QUOTE Thanks

02-26-09, 05:04 AM	#4
prime81 Member Join Date: Feb 2008 Location: Odessa, Texas	If your overclocking and crossfiring, he meant go for a higher PSU. Sure it may work, but it'll either be unstable or you'll blow your PSU. __________________ i7 2700K@4.8ghz w 1.36v(offset +.045) Corsair XMS 3 2 x 4gb 2000mhz CAS 9 Corsair H100 Sapphire HD7970 3gb OCZ Agility 3 240gb Antec 1200 Case SB recon3D/Sennheiser HD595s Zalman 850HP Powa! -Folding for Team32-
	QUOTE Thanks

02-26-09, 05:10 AM	#5
Rick James Disabled Join Date: Jan 2009 Location: Tempe, Az	I just picked up a 850W Raidmax on newegg for 100 bucks. Even has modular cables. Is awesome
	QUOTE Thanks

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02-26-09, 05:40 AM	#6
Rich'[ard] Member Join Date: Apr 2008 Location: Melb, AUS	it'll keep randomly restarting ^^ go for a 750/850W Corsair. they're rock stable. __________________ яι¢н. Processor 3570K @ 4.5GHz 1.2v Heatsink Noctua NH-D14 Motherboard Gigabyte G1 Sniper-M3 Memory 8GB Vengeance C9 Storage Samsung 830 120GB + Seagate Barracuda 2TB Graphics Powercolor 7950 PCS+ Power Corsair HX650 Case Corsair 300R Windows w7 64bit Goodies Logitech z5400 5.1............G15\|G3 HP Folio 13 Ultrabook
	QUOTE Thanks

02-26-09, 07:52 AM	#8
mattgmann Member Join Date: Sep 2008	If you have to buy one or the other, buy a power supply, and upgrade your video card later. Why does everybody whine about buying power supplies? It should be the first and most important component you pick out for your system. If you want to run an OC'd quad and 2 4870s, you need a GOOD 750W unit or better. Corsair is popular and reliable. Thought the 750tx isn't really that great of a performer, tons of people have it and swear buy it. Antec, PC power and cooling, BFG, Seasonic; these are all pretty reliable brands. Other brands you really need to research the individual model of the psu before buying. (i.e. raidmax. don't buy a raidmax, they're cheap and ****ty...you get what you pay for) __________________ i7 920 @4.5ghz -----------------------Q6600@3.6ghz x58 sli le-------------------------------Tpower i45 6gb ocz plat 1600 cas7 ----------------4gb pc2 6400 2X 4870s (800\1100)-------------------8800gt Antec Signature Series 850W---------Toughpower 650W
	QUOTE Thanks

02-26-09, 09:00 AM	#9
Hardin Member Join Date: May 2004 Location: Sumter, South Carolina	80% efficiency doesn't mean that it's only going to give you 480w. It means it's giving you the full 600w, but it's drawing more power in the form of heat to give you that power. http://www.silentpcreview.com/article28-page2.html http://forums.anandtech.com/messagev...&enterthread=y __________________ cpu-Intel Core i7 3770k ram-G.Skill 2x4gb DDR3-1600 gpu-Radeon HD 7870 motherboard-Asus P8Z68-V LE Last edited by Hardin; 02-26-09 at 09:07 AM.
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