Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

SPUY767

macrumors 68020
Original poster
Jun 22, 2003
2,041
131
GA
I just spent two and a half hours turning my MacPro into the fastest Mac and the Fastest PC in the world. (Latter assumes non-SLi setup.) Here's the trick. . . You have to have an extra PCI-E card laying around, Mine was a 7950GX2 1Gig. You remove the whimpy 7300 from its nest on the bottom. As this card is pretty lame, it can sit in the top. There is a neat trick on the MacPros, the firmware controls the speed of the PCI-E busses. Take your doublewide PC video card and slip it into the bottom slot.

Now, a good video card will need a seperate power lead, this is already taken care of. See, the kind folks at apple thought to include two four pin connectors for Graphics cards. Just find the correct dongle at any computer-centric electronics store, and go to town. Plug the power lead in and you're ready to go. Shore the case up, and make sure that all the cards are properly seated. Did I mention that you should have already installed windows??? It pretty much goes without saying, since anyone interested in this would have already installed boot camp and all.

Ok, boot up the beast. Let it boot all the way into the Mac OS. There will come up a warning saying that the PCI-E configuration was changed, and it gives you an option to select a new speed configuration. Number one is the one we want, 16x on the bottom, and 8x for the anemic 7300. If it's set up right, close it and restart. This time, hold down the [opt] key. The boot selection comes up. The computer is running off the 7300 at this point, but don't worry. Select your windows partition, and boot.

Windows will now go through it's traditionial horse poop, and tell you that new stuff is here and it wants to look for crap. Ignore it. Just download the GeForce or whatever drivers from your respective manufacturer. It will linstall, and you will need to restart again. Do so. Same procedure, [opt], windows, boot. Now everything should be working smoothly. Get any software you need, and you're ready to go!

Working on benchmarks now, hoping for some killer scores.

PCMark05 CPU: 9563
Super-Pi: 1M digits of pi in 7.68 Seconds, this is the fastest time I have ever seen posted on the internet. Screenies when i get back home.
 

BadRambo

macrumors member
Aug 20, 2006
64
0
So are you using the 7300 for your OS X graphics?? --- causing you to have to switch your monitor connection to do OS X ??
And where are the two DC connectors located --- I don't see them at first glance.
Thanks!
 

SPUY767

macrumors 68020
Original poster
Jun 22, 2003
2,041
131
GA
BadRambo said:
So are you using the 7300 for your OS X graphics?? --- causing you to have to switch your monitor connection to do OS X ??
And where are the two DC connectors located --- I don't see them at first glance.
Thanks!

My LCD Monitor has tow inputs, one VGA, on DVI, I plug the 7900 into the DVI, the 7300 into the VGA, since I'm never switching between the two at any given time, whenever the machine boots, the monitor automatically selects the correct input. Most LCD's work this way.

The DC Connectors are toward the fron of the machine by the spare SATA connectors. They are obscured by the front fan housing.
 

BadRambo

macrumors member
Aug 20, 2006
64
0
Hiya SPUY ----

OK, on the monitor inputs. That "computes" ;)

I spotted the two SIX pin connectors by the fan housing next to the SATA on board connectors. They are unusual. Are those the two you are referring to?
And you found dongles for THAT connector ???

Also too, how does the chassis cooling handle the HOT video card? I have a 7800 GTX PCI-E and they do require good cooling flow, especially when the GPU is really cranking on some serious 3D gaming. What say?

Thanks for all the info --- Bob --- :D
 

SPUY767

macrumors 68020
Original poster
Jun 22, 2003
2,041
131
GA
BadRambo said:
Hiya SPUY ----

OK, on the monitor inputs. That "computes" ;)

I spotted the two SIX pin connectors by the fan housing next to the SATA on board connectors. They are unusual. Are those the two you are referring to?
And you found dongles for THAT connector ???

Also too, how does the chassis cooling handle the HOT video card? I have a 7800 GTX PCI-E and they do require good cooling flow, especially when the GPU is really cranking on some serious 3D gaming. What say?

Thanks for all the info --- Bob --- :D

I was drunk when i wrote that, it was quite late, they are 6 pin connectors, I had mobo power on the mind. I can't find a pic online, but I got mine at fry's it's a standard PCI-E Power Cable, so I just assumed any other decent computer store would have it, maybe I'm wrong?

12-201-004-02.JPG


That's close to it. I haven't noticed a huge amount of heat coming from any parts of the machine. This thing runs wicked cool. While the G5 I had was a heater, this thing is practically an air conditioner, and when running near idle, the temp is actually below ambient. Framerates are astounding, besting my PC gaming rig by about 10-15% depending on the game.
 

BadRambo

macrumors member
Aug 20, 2006
64
0
Well, interesting. Guess this is the first time I have run across that particular connector. I am headed for my local Fry's. Will see what I can find. If this really works, it will surely be a piece of major upside. I do all my gaming in Windows, and other work in OS X. Will be an ideal setup, especially when Apple gets the drivers cleaned up for the rest of the Mac Pro issues.

Will let all know how I make out --- depends on finding that cable!!!

Cheers -- :D
 

SPUY767

macrumors 68020
Original poster
Jun 22, 2003
2,041
131
GA
BadRambo said:
Well, interesting. Guess this is the first time I have run across that particular connector. I am headed for my local Fry's. Will see what I can find. If this really works, it will surely be a piece of major upside. I do all my gaming in Windows, and other work in OS X. Will be an ideal setup, especially when Apple gets the drivers cleaned up for the rest of the Mac Pro issues.

Will let all know how I make out --- depends on finding that cable!!!

Cheers -- :D

If your half decent with vinyl tape, you can just buy two of the 4-6 pin jobs as they are abundant, strip the right wires and link the two together. I've done that to make custome cables before with my PC.
 

BadRambo

macrumors member
Aug 20, 2006
64
0
Well, at this point, you have me beaten. I cannot find this mating connector anywhere. It is not a standard used at all on PCs. It is like a shrunken PCI-E connector, about 2/3 the size of a PCI-E. Tried Fry's -- no go. It is possible it is a standard connector used by Apple.

What is interesting too, is that the conductor size in the connector on the mobo, are very small for high current application like PCI-E for vid-cards. If you get any more clues about where a dongle with connector on it can be found, let me know. Until then, I will snoop around a bit on the net.

Note this site where they go through a disassembly of the Mac Pro with many photos. Some of the photos show these sockets being used, even apparently for the Quadro Apple card's own added DC input.

http://www.powermax.com/articles_reviews/article.php?id=32

So it definitely appears to be an "Apple exclusive" connector type but is used to supply (apparently) DC for vid cards and other items...

Cheers --- Bob --- :confused:
 

SPUY767

macrumors 68020
Original poster
Jun 22, 2003
2,041
131
GA
It's a standard connector, not necessarily in the world if PCI-E, but I thought the same thing when I first saw it, "WTF?" Then I remembered I had a device that looked not unlike it, that's what compelled me to go to fry's in search of the bounty. Apparently I just got lucky. :-(
 

BadRambo

macrumors member
Aug 20, 2006
64
0
SPUY767 said:
It's a standard connector, not necessarily in the world if PCI-E, but I thought the same thing when I first saw it, "WTF?" Then I remembered I had a device that looked no unlike it, that's what compelled me to go to fry's in search of the bounty. Apparently I just got lucky. :-(
------
Yep, probably made by Molex or some other big connector house -- anyway, I sure am out of sources --- unless I can identify the maker and a part number, then I can build my own cable....until then.... Thanks for trying.

:D
 

SPUY767

macrumors 68020
Original poster
Jun 22, 2003
2,041
131
GA
BadRambo said:
------
Yep, probably made by Molex or some other big connector house -- anyway, I sure am out of sources --- unless I can identify the maker and a part number, then I can build my own cable....until then.... Thanks for trying.

:D

I can't get a part number, but I'll tell what the one I had went to. It was DC power supply for a FSR VGA Switch.
 

t0pcat

macrumors newbie
Aug 24, 2006
6
0
Dude, did you say you used a 7950gx2? i got mine working in windows nothing special there but under osx i got kernel panics on boot :eek: ... with a 7800gtx in its fine...

what brand 7950GX2 have you got???
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.