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Old Oct 10, 2012, 01:53 AM   #76
Redneck1089
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Originally Posted by slughead View Post
Yep, that's pretty much how I assumed you had it setup. At least it looks like you're using a reference card GTX670 (lower power than the others). The greatest resistance is going to be right on your SATA connector.

Image

Those three tiny 12 volt squares of metal have to handle up to 12 amps in your setup. They are rated for 1.5 amps each according to this--totalling 4.5 amps. That's only 54 watts, when it should be 150 watts

Again, it probably wont break any of the expensive components (like the motherboard or PSU... provided Apple isn't using single rail...). However, potentially you could have some issues with damage to the wires, lower framerates, and software instability.

If it works for everything you're using it for and you're okay with the risk, I guess there's no reason to change anything. Just don't play Battlefield 3 on max or that little connector is going to be very upset with you

OKAY!! I went today and bought a Corsair Professional Series HX650 Modular Power Supply. I also bought two 18" 6-pin extender cables.

I used the paper clip method you suggested on the green and black wires to jump start the PSU. I also wrapped the paper clip in electrical tape just to be on the safe side.

The hardest part was routing the 6-pin cabins from the PSU back into the case. I have two double wide video cards in there as well as a LaCie PCIe USB 3 card, so it looked like doing the routing from the back of the case was out of the question.

I thought about routing the cables through the empty optical drive bay space...but alas the cords, even with extensions, weren't nearly long enough. I also didn't want to create more resistance as MacVidCards warned about by adding further extensions.

I went back and pulled the PCIe USB 3 card out...took it to a vice and put the end of the metal bracket in between the clamps. I gently bent the metal bracket of the card back and forth until the metal snapped off. Then I had an inch of room for the 6-pin extensions to fit through even with the PCIe USB 3 card installed.

Now the whole computer is running beautifully. I should no longer have any worries about over-extending my computer's power limits!

Thanks for everyones' help!!







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Old Oct 10, 2012, 03:52 PM   #77
slughead
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Originally Posted by Redneck1089 View Post
OKAY!! I went today and bought a Corsair Professional Series HX650 Modular Power Supply. I also bought two 18" 6-pin extender cables.
Very nice setup!

For others doing it in the future who may wish to have longer 6/8 pin extension cables: I am in total disagrement with MacVidCards on the extension cables causing "resistance" thing. Even 6 feet of extension is not going to significantly impair voltage--at least not at 12 volts (higher voltage has less power loss per watt per length).

Edit: Okay I did the math just to prove it: 18 gauge wire has 0.038 Ohms over 6 feet.

Say we're maxing out the tolerances of this Eight pin cable--a situation which would result in the most wattage lost. I don't even think the GTX670 is capable of this, but maybe you're liquid cooled and overclocked to the hilt. So at that wattage, that means we're doing 4.2 amps per wire at a maximum of 50 watts (8 pin cables do 50 watts/wire max): at that amperage, you lose a total of 2.0 Watts/wire - 4%. Acceptable voltage tolerances are +/- 10%.

Keep in mind 4% is the WORST CASE SCENARIO, which is likely impossible with the GTX670. If you're not overclocking, more than likely you'll be using less than half that amperage at most with the GTX670. The equation is exponentially higher based on amps -- so normal usage ( half the above amperage : 2.1 amps/wire) is only a loss of 0.67% with 6 FEET of extension!

The length variable of these equations has a linear effect , so since 6 feet is a 4% loss (we'll again pretend you're drawing twice what you likely would); 3 feet at maximum wattage would be a 2% loss. If 3 feet is a 2% loss, 18 inches is a 1% loss!

Therefore, we conclude that most likely an 18" extender or thereabouts will lose 0.17% wattage at maximum load if you're not overclocking, which will be perfectly within keeping of the ATX 2.2 standard (which all components accept) of +/- 10%



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Quote:
Originally Posted by Redneck1089 View Post
If I put the computer to sleep can I leave the external PSU running or will I have to turn it on and off each time?

EDIT: Thanks again for your help.
You can leave it running, should be okay.

Last edited by slughead; Oct 19, 2012 at 07:55 AM.
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Old Oct 11, 2012, 03:29 PM   #78
fergusonbk
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just want to let yall know I finally got windows working last night (it wouldn't install properly, something about too many hard drives in my mac pro, pulled them all out other than the install one and it worked fine).

downloaded a couple games: borderlands 2, crysis 2, the heaven benchmark..

everything ran like a BEAST. with all settings pumped to the max in borderlands 2 I got about 60fps, crysis 2 ran like butter and looks amazing (no fps count), and heaven runs beautifully and about 20-30fps higher than in MacOS (direct 3d?). Basically this card rocks, rock solid so far in OSX and windows is on fiya.

holla

Dave
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Old Oct 18, 2012, 12:37 PM   #79
Drunky
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Originally Posted by Redneck1089 View Post
Get a SATA to molex connector. I'm powering one of my cards from my drive bay using a SATA to molex cord.
Which SATA to molex cable did you use, 15-pin to 4-pin, am I right?
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Old Oct 18, 2012, 02:54 PM   #80
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Which SATA to molex cable did you use, 15-pin to 4-pin, am I right?
Correct.
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Old Oct 19, 2012, 07:38 AM   #81
slughead
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Which SATA to molex cable did you use, 15-pin to 4-pin, am I right?
don't do it! we just spent 2 pages of this thread convincing him to stop that lol
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Old Oct 26, 2012, 06:43 AM   #82
skiffx
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Hey guys just to make sure, I have a 5,1 and a spare gt120, so all I need to buy is EVGA GeForce GTX670 2048MB that has 6pin connectors (thus I dont need any adapters or anything?) and I should have a bootscreen available from gt120? I then can just boot into windows and isntall nvidia drivers for gaming? I also have 4 dvi monitors 3x30" and 1x24", any problems there?

Also I dont do any graphics work, but I do need a lot of video ram for virtual machines, so maybe I should go with 4gb version? I dont wanna tinker with any kexts for OpenCL support, not sure if I need it just to run mountain lion and a win 7 VM. (and it works for gaming under bootcamp as I understand)

Thanks for the input.

Last edited by skiffx; Oct 26, 2012 at 07:30 AM.
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Old Nov 21, 2012, 11:12 AM   #83
Drunky
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Hey people, I've finally managed to get the right cable as temporary solution (my GT120 is on the way). But I can't figure out how switch graphics cards in Windows, it keeps on using the old ATI card. For sure, my monitor is connected to the 5770, I can switch the cable while the OS is on and everything will work. Is there any other way, probably somewhere in settings?
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Old Jan 15, 2013, 10:03 PM   #84
sunsetsothickly
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Full-speed in Win7?

Hi guys,
Looking to put a 2GB 670 in a 5,1 4C 3.2, 32GB RAM. Idea is to have both my everyday (OSX) system and analysis system (Win7-64) in one box, rather than running from one to the other.

I am very encouraged by the ML and 6XX successes, and am not fussed about the lack of a bootscreen, but am concerned about what people have said about cards only running at PCIe 1.0 rather than 2.0 speeds when being used in Bootcamp. Is this true? If so, is it really of any consequence? In Win7, I am using only Amira to visualise, segment, measure in large (~14GB) datasets.

Does anyone have any experience running Amira or Avizo on 6XX cards?

Ta
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Old Jan 30, 2013, 08:49 AM   #85
TheDoktor
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No video signal in Bootcamp

After reading this review I also decided to upgrade my Mac Pro (2010) with the Gigabyte 670. I chose the 4GB version, as I don't really care about OpenCL, but much rather about a good gaming performance.

The card works just fine on my freshly installed OSX Mountain Lion, however, if I try boot up windows I only get a blackscreen, even if I leave it to rest for a while no change happens.

I was wondering if anyone else here has experienced this issue and knows a fix for this. I have read that I should boot windows with an older Nvidia card, but I don't own such a card and I dont really want to buy one just to get the 670 to work, too.

I could lend a 570 from my friend, but I don't know if that would be of any help either.

Thanks in advance.

- Doktor


EDIT: With the help of Bootchamp I can now run windows, but I before I get into windows, I always need to start up Mac OSX first, then reboot directly into windows. I can live with this, but I would prefer to choose at startup whether I want to use OSX or windows 7.

Last edited by TheDoktor; Jan 30, 2013 at 09:22 AM.
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Old Feb 3, 2013, 07:41 AM   #86
slughead
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Originally Posted by TheDoktor View Post
After reading this review I also decided to upgrade my Mac Pro (2010) with the Gigabyte 670. I chose the 4GB version, as I don't really care about OpenCL, but much rather about a good gaming performance.

The card works just fine on my freshly installed OSX Mountain Lion, however, if I try boot up windows I only get a blackscreen, even if I leave it to rest for a while no change happens.

I was wondering if anyone else here has experienced this issue and knows a fix for this. I have read that I should boot windows with an older Nvidia card, but I don't own such a card and I dont really want to buy one just to get the 670 to work, too.

I could lend a 570 from my friend, but I don't know if that would be of any help either.

Thanks in advance.

- Doktor


EDIT: With the help of Bootchamp I can now run windows, but I before I get into windows, I always need to start up Mac OSX first, then reboot directly into windows. I can live with this, but I would prefer to choose at startup whether I want to use OSX or windows 7.
I had the same problem, it ended up being the ATI catalyst driver. I uninstalled it and it worked after that.
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Old Feb 3, 2013, 07:53 AM   #87
Bah-Bah
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Could someone please advise on how a GTX 660 ti will get on in a 2008 Mac Pro in mountain lion? Is there anything that won't work, ie DVDs, Steam etc.

Thanks
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