Rješenje za ploče s RD480 chipsetom

[McG]

We have a solution for problems that we have had with A8R-MVP motherboard and two graphic cards. ATi key motherboard designer John Bruno told us that a single rail PSU is better than a multi rail PSU. He reported that ATI had some issues with multi rail PSUs while all of the single rail 500 W + PSUs were running fine. It turns out that both OCZ Power stream 600 W PSU and Akasa 650W PSU are using more than one power rails.

We got a nice link where one of the top overclocker, our good friend Sampsa had the same problem with 600W multi rail PSU and A8R-MVP board and two X1900 cards in Crossfire. He solved its troubles by switching to a single rail 560W PSU.

This specific problem reminded us on the same problem that we had with two Geforce 7800 GTX 512 cards. Those two cards in SLI were crushing the machine while two 7800 GTX 256 MB cards worked flawlessly. Someone simply could suggest that we should try single rail PSU 500+ W and everything should work. SLI works with two 7800 GTX 512 after all.

Hurray, now we know that Nvidia and ATI should warm people that they need single rail PSU not just any 600 W PSU. That really makes the difference. We are speechless why no one warned the users about this issue.

Izvor: Inquirer

[McG]

We conducted an in-depth investigation about power supply units (PSUs) and the problems that you might face when using high end SLI/Crossfire systems. The recent problems we had with single and dual rail PSUs made us look first at the ATX 2.0+ specification.

The essence of the problem actually lies within the big four, Intel, AMD, Nvidia and ATI. They are all guilty for going too far, too fast with power specifications, in order to reach the performance crown, of course. For example, the ATX 2.0 specification requires two 12V power rails or more and some of the manufacturers designed two rail designs at around 20 amperes per rail. The problem is that Intel's Extreme Edition or Athlon FX60 can easily reach that. We learned that Intel's latest Extreme edition draws 22 to 23 amperes of its default 3.73 GHz clock speed. As soon as you overclock the same CPU at 4.4 GHz your CPU will draw as much as 28 to 30 amperes but this number includes all the fans and the pumps that you need to keep the beast cool.

Very knowledgeable engineers confirmed to us that a card such as the Geforce 7800 GTX 512 or Radeon X1900 XTX requires roughly 12 to 15 amperes. Once you plug those cards in SLI/Crossfire mode, they will need twice as much. Once you overload one of the 12V rails, the machine will simply shut down in order to prevent the destruction of your expensive machine.

So, you do the sums - a CPU with up to 30 Amperes plus two cards that need additional 30 amperes will get you to monstrous 60 Amperes. If you don't do a dual rail design you are risking setting your PC on fire, and if it weren't for those safety mechanisms, you could easily see some real fire from your PSU. You could blame Intel for its extreme CPUs, you could blame AMD for its FX 60s - almost as bad with the power consumption, you could blame Nvidia for its SLI that started this whole mess and you could blame ATI who followed Nvidia and made Crossfire.

Izvor: Inquirer, Extreme Tech

[McG]

Thermaltake has announced its new Purepower Power Express 250W dedicated power supply for graphics cards. With today's SLI and CrossFire cards requiring more and more juice, this dedicated PSU takes some of the load off your system's power supply.

The Purepower Power Express fits into any standard 5.25" drive bay and features two 6-pin PCI Express connectors to supply power to your graphics cards. It also works in conjunction with your current power supply with an included adapter. For those of you concerned about noise levels, the PSU's 4cm fan puts out 20dB at 2000RPM.

Napajanje

Izvor: DailyTech