Will FSPx5 in Mac Pro power GTX 580 and 8800GT cards?

[samsax]

I was considering using the FSP X5 Supplementary PSU in my 2008 Mac Pro to help power two cards: Nvidia 8800GT and a GTX 580 Classified.

8800GT connects via a single 6 pin. But the GTX 580 Classified requires two 6 pin and one 8 pin connectors.

Can I split the load of the GTX 580 by attaching one of its 6 pin connectors to the Mac Pro's PSU, and the other 6 pin and the 8 pin to the FSP's supplementary PSU?

If not, would the FSP unit be able to power the GTX 580 on its own? It is 450 W (and I think 37.5 Amps per rail). The GTX 580 requires minimum system power of 600 W and a max graphics card power of 244 W. The Mac Pro's PSU is 950 W - but I have all 4 hard drives running and one optical derive attached.

Is a card completely connected to the FSP 450 W unit still able to draw power from the computer's main PSU through the PCI slot?

Another card I am considering which might be easier to use is the GTX 570 - which only requires 2x 6 pin connectors. I can use that in the Mac Pro with no additional PSU, but then I don't know how I would power the 8800GT.

Any help or advice much appreciated.

Until I came upon all the great info in these forums I was clueless about PSU's; now I'm just confused

Thanks!

 

[amuffin]

What are the amperages of the psu's? Are you sure the 580 will even work with your mac pro?

 

[nukemaster]

My guess...should be up to the task, i do not think it will be quiet(may be better with the 8800GT on the mac power supply and the new card on this, the less it works, the quieter it will be.)....

http://www.newegg.ca/Product/Product.aspx?Item=N82E16817104054

What are the specs on that system of yours.

A good 950 watt power supply will have NO problems at all(Hell, I had no problems with lots of hard drives ever 6-8 on far smaller power supplies.). If you went the 570 route, you can just use a molex to pci-e adapter for the 8800GT.

As noted above, some video cards may not work, back in the day, they needed a bios flash to work.

 

[samsax]

Thanks for the confirmation that the FSP should work! I will do as suggested (hook new card up to it).

Regarding GTX 570 in Mac Pro: I hear it works fine under Bootcamp. And improvements in in OS X 10.7.2 make it much easier to use on the OSX side as well - no longer requiring flashing. Apparently all one needs is to install the ATY_Init kext from Netkas and add the card's device ID (on newer Macs there is one additional step). This means you don't get the boot screen, though - which is fine with me.

I will be using the card headless solely to power a 3d rendering program called Octane (which exclusively uses Nvida Cuda GPU's)

That's why I need to keep another card for my display.

I found a similar question in another forum, although that person was using a PC and had a primary PSU much less powerful than mine. The post has a very detailed response covering amperages and capacities between the cards, PCI boards, and the PCI-e connections. Though I don't fully understand all of that - it seems to be saying the FSP is fine to use for powering a separate graphics card (though the one in that post is older than the one I want to use).

http://www.eggxpert.com/forums/permalink/679582/679589/ShowThread.aspx#679589

Specs for Mac Pro:
Mac Pro 2008 (3.1)
2x 2.8 Quad Core Intel Xeon
Apple 950 W PSU
10 GB RAM
3x HDDS 1 TB 7200 RPM
1 HDD 2 TB 5400 RMP
ATI Radon HD 2600 (primary card for display - will be replaced)
Nvida 8800 GT (currently being used headless)

 

[nukemaster]

The fsp is made for that reason so it will have no issues.

That said, you know you have to connect it to your main power supply with a molex(4 pin) connector right? This is how it will know it has to power up.

Since I am not sure the exact Zeon's you have, it is hard to guess the exact power they take. If they are core2(conroe or newer) based it would be you still have a fair bit of extra power left over. Since i am not sure the exact upgrade cycle from those systems, it would be a guess at best.

With the extra power supply, all the load would be on it(well, some may come off the board, but with the kind of power connectors your card has, it would be able to get ALL of it from the extra power supply.), so the main power supply would not be working any harder(if fact less hard since the 2600 will be gone and the 8800 will not be working as hard.).

So all this power and not gonna game a bit

 

[amuffin]

Do you know what amperages that psu has?

 

[samsax]

Ordered both the card and power supply from Newegg today.

you know you have to connect it to your main power supply with a molex(4 pin) connector right?

I do know that the FSP Booster connects to main PSU via molex. What I am unsure of is whether I need some kind of adapter or not. There is one female 4 pin molex free from in the Mac's empty second optical drive bay (where the FSP will go). I'm assuming the FSP will have male molex connectors? I could not get that info from either Newegg nor FSP's site. So I will wait and see.

So all this power and not gonna game a bit

Haven't gamed in a long time since I was first learning multimedia. I remember playing till 5am every night with intense adrenaline highs, getting a few hours sleep and then trying to get up to go to work.

I stay up too late as it is now just trying to keep up with everything; not sure I can handle the additional excitement

Do you know what amperages that psu has?

I know very little about the Mac's PSU at this point. But the FSP Booster is listed as 37.5 amps.

 

[nukemaster]

I'm assuming the FSP will have male molex connectors? I could not get that info from either Newegg nor FSP's site. So I will wait and see.

It will be just like plugging in an old hard drive or even a cd/dvd rom. It is most likely nothing more then a relay on the power supply to start it when 12 volts is seen. Then the power supply will give you 4 pci-e connectors(2 x 6 pin and 2 x 6+2 pins iirc)

I know very little about the Mac's PSU at this point. But the FSP Booster is listed as 37.5 amps.

Check the sticker on the power supply, it should have all the specs. Even if you take a picture of it.