2nd graphic card on 2nd psu

[redrabbit]

my current system: Asus M4a78+/CF edition
AMD 7750BE
Radeon hd4850
3gb Kingston RAM
Asus DVDRW
1Tb seagate HDD
500W Cooler Master PSU

this is my current setup. i plan to add hd4870 and create mixed crossfire with hd4870 as my primary graphic card. I dont think my psu is strong enough for Cf configuration so:

Is it safe to power hd4850 alone using 2nd daisy-chained psu?

 

[JohnnyLucky]

Since you are going to be spending money why don't you get a high quality power supply that can support a system with two video cards operating in dual mode? Coolermaster makes great pc cases but their power supplies are not stellar performers.

Here are the official ATI recommendations:

500 watt or greater power supply with two, 75 watt, 6-pin PCI Express® power connectors recommended.

600 watt or greater power supply with four, 75 watt, 6-pin PCI Express® power connectors for ATI CrossFireX™ technology in dual mode.

 

[JackNaylorPE]

As usual, I'm gonna echo the other skeleton guy up there and suggest a replacement PSU rather than twin ones. A 650 watter can handle all of the ATI 58xx cards and below; an 850 watter can handle just about anything else. The lists below contains performance ratings (10 scale) at jonnyguru.com / prices as per newegg last week and ones w/ double asterisks (**) made it onto silentpcreview.com's Editor's Choice List meaning they excelled at both electronic and acoustic performance:


Antec Signature 650W (10.0) OOS **
Seasonic X-650 650W (10.0) $160 **
Silverstone Olympia OP650 (10.0) NFS

Thermaltake Toughpower QFan 650W (9.5) NLA

Antec Earthwatts EA650 650W (9.0) $75

Antec True Power Trio 650W (7.5) NLA

XFX XPS 650W XXX Edition Power Supply (7.0) NFS

Antec NeoPower Blue 650W (6.5) NLA

BFG BFGR650PSU 650W (6.0) NLA

NorthQ Black Magic Flex 650W PSU (5.0) NFS




Antec SG-850 - 10.0 ($220) **
Antec CP-850 - 10.0 ($110) **
XFX 850W Black Edition 10.0 ($185)
Corsair HX850 850W - 10.0 ($180)

Antec TruePower Quattro (TPQ-850) - 9.5 ($150)
Corsair TX850 - 9.5 ($140)
Seasonic M12D 850W - 9.5 (NLA) **
NorthQ Giant Connector 850W - 9.5 (NFS)
Etasis ET850 - 9.5 (NLA)
Silverstone Zeus ST85ZF - 9.5 (NLA)

Enermax Revolution 85+ 850W - 9.0 ($250)

Thrmaltake Toughpower XT 850W - 8.5 ($216)
OCZ Z Series 850W - 8.5 ($200)

NorthQ Black Magic Flex 850W - 8.0 (NFS)
Coolmax CTG-850 - 8.0 (NFS)

SilverStone Decathlon DA850 - 7.5 ($230)
Enermax Galaxy DXX 850W EGX850EWL - 7.5 (NFS)

SilverStone Strider ST85F - 7.0

Silverstone Element ST85EF 850W - 6.0

NFS - Not For Sale / NLA = No Longer Available / OOS - Out of Stock

 

[geofelt]

1) How do you plan to daisy chain a second psu? For a normal psu, it is turned on by the motherboard which has only one main power connector.
There are some auxiliary specialty psu's intended to power a graphics card, and they have a special cable to connect to the originating psu in some way.
Here is an example:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817104054

2) Does your 500w psu have two 6-pin pci-e connectors? If not, it is probably inadequate for just the 4870. In addition, you would have to use a molex to pcie 6pin adapter.
One is often included with the graphics card, but having to use it is not a good thing unless your psu has extra power.

3) As johnnylucky said, consider a good quality psu. Get one with at least three 6-pin pcie connectors for your proposed configuration.
Look to Corsair, Seasonic, Antec, or PC P&C. For example:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139012

4) Are you certain that a second vga card will give you the FPS you require for your resolution?

 

[redrabbit]

tq 4 the replies. forgot to mention, i have extra 450w psu from my case and i do have an auxiliary specialty psu connector to jump start my 2nd psu.