Running an ATI Radeon HD 5870 on a 450W PSU

[kenbo43]

ATI Radeonâ„¢ HD 5870 System Requirements

* PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard
* 500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended (600 Watt and four 6-pin connectors for ATI CrossFireX™ technology in dual mode)
* Certified power supplies are recommended. Refer to Page Not Found for a list of Certified products
* Minimum 1GB of system memory
* Installation software requires CD-ROM drive
* DVD playback requires DVD drive
* Blu-rayâ„¢ playback requires Blu-ray drive
* For an ATI CrossFireXâ„¢ system, a second ATI Radeonâ„¢ HD 5870 graphics card, an ATI CrossFireX Ready motherboard and one ATI CrossFireX Bridge Interconnect cable per graphics card (included) are required

ATI Radeonâ„¢ HD graphics chips have numerous features integrated into the processor itself (e.g., HDCP, HDMI, etc.). Third parties manufacturing products based on, or incorporating ATI Radeon HD graphics chips, may choose to enable some or all of these features. If a particular feature is important to you, please inquire of the manufacturer if a particular product supports this feature. In addition, some features or technologies may require you to purchase additional components in order to make full use of them (e.g. a Blu-Ray or HD-DVD drive, HDCP-ready monitor, etc.).


I just bought an ATI Radeon HD 5870

It says 500W psu is "Recommended" could i get away with using my 450 psu or do i need to by a new psu?

 

[Muffin Man]

if it's a quality psu from a name brand like seasonic, corsair or like pc power & cooling then it might work, depends on what other components are in the system.

what psu is it (brand + model)?

 

[CalcProgrammer1]

The HD5870 draws up to 175A full load from what I've read, mine seems to draw significantly less if the readings from the onboard Volterra VT1165 monitoring chip are to be believed (1.24V, 42.97A while folding on it, P=IV=(1.24)*(42.97)=53.2828W) and a bit more during gaming. I have mine overclocked to 900/1300 as well. I think you can get by with the 5870 as long as you don't have too much else in your system (single HDD, single optical drive, non-overvolted CPU, etc) and have a good brand name 450W *continuously rated* PSU. A 450W continuous PSU should probably work but a 450W peak PSU (what cheaper brands tend to judge power output by) will not.

 

[Yami]

175A is well over the rating of most high-quality 1200W PSUs. I think you've got the wrong number somehow

 

[CalcProgrammer1]

Oops...175W lol, 175A is huge at 12V (12*175 = 2100W!). At 1.24V the chip should theoretically use up to 175/1.24= 141A but the controller isn't 100% efficient and I doubt it would ever use this much current. I think you'll only hit the 175W consumption limit from over-volting. 175W/12V=14.58A, so your 12V rail must be capable of at least 15A for the graphics card.