Nvidia GeForce GTX 980 on 5.1

[gr8pics]

Great, i got a SSD in bay 1, so i can just reassign that then

Im not sure what this means:

"P.S. In my above link, I ran through the R17 mod to get PCIe 2.0 speed. I ONLY recommend to run this mod if the card run at x4 slot. As you can see in my sharing, the PCIe 2.0 x4 bandwidth can bottleneck the 7950 a little bit. I am not sure what's the penalty if further cut the bandwidth by another 50%. However, if you manage to run both card in the x16 slots. There is no need to mod anything."

If i get two 7950 ref, and i just plug them in, are you saying i can reach a bottleneck with stock PCIe?

 

[h9826790]

Did you read my link?

https://forums.macrumors.com/thread...tem-information.1808938/page-14#post-21607156

https://forums.macrumors.com/thread...mac-with-2-d700s.1732849/page-5#post-21722712
[doublepost=1487001059][/doublepost]

If i get two 7950 ref, and i just plug them in, are you saying i can reach a bottleneck with stock PCIe?

If you can install them in slot 1 and 2, then NO, no penalty.

Only if you decide to install one card in a x4 slot (e.g. slot 3), then an un-modded 7950 can be bottlenecked.

 

[gr8pics]

Did you read my link?

https://forums.macrumors.com/thread...tem-information.1808938/page-14#post-21607156

https://forums.macrumors.com/thread...mac-with-2-d700s.1732849/page-5#post-21722712
[doublepost=1487001059][/doublepost]

If you can install them in slot 1 and 2, then NO, no penalty.

Only if you decide to install one card in a x4 slot (e.g. slot 3), then an un-modded 7950 can be bottlenecked.

Hmm, that looks pretty tight? Its about same size as my 7970?

 

[h9826790]

Hmm, that looks pretty tight? Its about same size as my 7970?
View attachment 688401

Yes, it's tight, but just fit in. The 7950 has the same height as the 7970.

 

[gr8pics]

Awesome, then ill be getting two 7950s.
So what i need in addition, is a 6 pin splitter?

 

[h9826790]

Yes

 

[gr8pics]

Thx!
Ive been rendering for an hour on my 7970 now, heres the current draw and temps, doesnt look bad, only a few degrees difference

 

[Nessdufrat]

Hi there, sorry to barge in on that thread.
I have a question about the GeForce 980. I recently acquired a Mac Pro 2009 (4,1, but I plan on upgrading the processor to an Hexacore and changing the graphic card, right now I have the GT120 inside). My idea was to buy the GTX980, but not the flashed one, since I'm following one on eBay nearby and it might not go very high (I'm in France, so I have to look for something local anyway because of taxes) and I have a few macs lying around so I can always do the screen sharing thing.
BUT, I was wondering... Technically, what prevents me from installing the gtx980 AND the GT120 at the same time first, having the screen on the GT120, installing the drivers for the GTX980 (ok, for the 600, because I read the full thread and there are no official drivers, but whatever, the drivers that are compatible for the 980), they WILL install since the GTX980 is plugged in, then I remove the GT120, I boot the computer and voila. Or? I've never worked with dual graphic cards before, so it's purely theoretical. Maybe it requires some kind of bridge or something, so that's why I'm asking first. Also, I guess even if I do that, I shouldn't leave the GT120 inside since I heard it might drag the performance of the GTX980 down.
Also, last question, should I upgrade the processor first or will it work when it's still in its 4,1 configuration? (I think there's an EFI update I should do, though. Sorry, I just got the computer, so I'm still new at that, very first Mac Pro, I've only ever had MacBooks until now) Thanks for your advice.

 

[h9826790]

Hi there, sorry to barge in on that thread.
I have a question about the GeForce 980. I recently acquired a Mac Pro 2009 (4,1, but I plan on upgrading the processor to an Hexacore and changing the graphic card, right now I have the GT120 inside). My idea was to buy the GTX980, but not the flashed one, since I'm following one on eBay nearby and it might not go very high (I'm in France, so I have to look for something local anyway because of taxes) and I have a few macs lying around so I can always do the screen sharing thing.
BUT, I was wondering... Technically, what prevents me from installing the gtx980 AND the GT120 at the same time first, having the screen on the GT120, installing the drivers for the GTX980 (ok, for the 600, because I read the full thread and there are no official drivers, but whatever, the drivers that are compatible for the 980), they WILL install since the GTX980 is plugged in, then I remove the GT120, I boot the computer and voila. Or? I've never worked with dual graphic cards before, so it's purely theoretical. Maybe it requires some kind of bridge or something, so that's why I'm asking first. Also, I guess even if I do that, I shouldn't leave the GT120 inside since I heard it might drag the performance of the GTX980 down.
Also, last question, should I upgrade the processor first or will it work when it's still in its 4,1 configuration? (I think there's an EFI update I should do, though. Sorry, I just got the computer, so I'm still new at that, very first Mac Pro, I've only ever had MacBooks until now) Thanks for your advice.

You can install GT120 with 980 at the same time. The only limitation I know is the Windows driver. If you only use MacOS, I don't know there is any software limitation stop you doing that.

Anyway the web driver is official, but just from Nvidia, not Apple.

If you plan to upgrade the processor. Don't rush, update the firmware to 5,1 first.

 

[Nessdufrat]

Ok! I actually won the auction, so I guess I'll go ahead and try this card ^^ I'm just having some doubts about how to plug it in, since it's a PC Card, it will come with PC connectors. I'd like to go ahead and order the right cables so that I can try the card right away (in case I have any problems with it, so that I can contact the seller), is that actually two 8 pins cables or one six pin and one 8 pin? I got the PNY GTX980 (maybe the brand makes a difference, I don't know). It's not that big of a deal, I can still wait and put it in my PC to test it first. And in case I really can't make it work with the mac, it will stay in th PC, I was actually hesitating between getting a good graphic card for the PC or for the mac, and the mac was the lucky winner here.

 

[JMacHack]

Question: I thought the Mac Pro 5,1 didn't support Crossfire, so why run dual GPUs?
Or am I mistaken and it does support crossfire?

 

[Nessdufrat]

My point was not to actually run dual GPUs, just to have both during the installation of the GTX980 to avoid any troubles. But I guess it would draw too much power anyway, so I'll stick with the screen sharing solution during the install. Not sure how to do that, I'll have to google it. Can't believe I've been using macs for 15 years already and I've never tried that before. But I've got three other macs lying around so I guess the screen sharing option shouldn't be a problem.
BUT, I did come across a thread where somebody was explaining he was actually using two GTX970 inside his Mac Pro 5,1. I guess it is possible.

 

[h9826790]

Question: I thought the Mac Pro 5,1 didn't support Crossfire, so why run dual GPUs?
Or am I mistaken and it does support crossfire?

5,1 do support crossfire. I did that, 100% confirm. Of course, only work in Windows, but not MacOS.

However, crossfire is just a technology to use multi GPU for 3D stuff. Using multi GPU for compute is totally another matter.

Multi GPU support is not equals to crossfire. No crossfire doesn't mean multi GPU is meaningless.

 

[babyjoe]

Is it really worth buying a flashed NVIDIA card (lets say the 980 ti)? Doesn't it work right away with the correct driver for Sierra?

 

[William Payne]

Is it really worth buying a flashed NVIDIA card (lets say the 980 ti)? Doesn't it work right away with the correct driver for Sierra?

It depends on whether you want a boot screen or not. Flashed cards will have it, non flashed cards won't.

 

[babyjoe]

It depends on whether you want a boot screen or not. Flashed cards will have it, non flashed cards won't.

Seems like a lot of money to spend on just a boot screen. If you compare the prices on MVC to another used card, it's almost double the price...

 

[William Payne]

Seems like a lot of money to spend on just a boot screen. If you compare the prices on MVC to another used card, it's almost double the price...

It depends entirely on your needs.

 

[pierrox]

I have one, there is something “safe" about them, in the sense that you don't have to fear about breaking a driver since you'll always be able to start and get to your desktop.
Worth the extra, not sure. I'm considering going for a 1080 for more power, and would probably go for a regular. Having said that, my flashed 980Ti would be for sale...

 

[h9826790]

Is it really worth buying a flashed NVIDIA card (lets say the 980 ti)? Doesn't it work right away with the correct driver for Sierra?

Even you need the boot screen. GT120 + 980Ti combo may be a better choice.

Pros: cheaper, the boot screen can follow the GT 120 to another graphic card combo later.

Cons: extra slot require, Windows driver may cause issue in some particular GPU combo.

 

[babyjoe]

Even you need the boot screen. GT120 + 980Ti combo may be a better choice.

Pros: cheaper, the boot screen can follow the GT 120 to another graphic card combo later.

Cons: extra slot require, Windows driver may cause issue in some particular GPU combo.

Why is it necessary to see the boot screen?

 

[h9826790]

Why is it necessary to see the boot screen?

Almost never for most people. But some people may want it for single user mode etc.

 

[flowrider]

Why is it necessary to see the boot screen?

This question is asked over and over. Some swear they don't need it. Me, on the other hand need and use it. I would feel lost without it.

Lou

 

[pierrox]

Reading some of the feedback with High Sierra, it looks like you need it to install the new OS.

 

[joot]

I have a gt120 and 980Ti in my 4,1 flashed to 5,1. The easiest way for me to power the 980Ti is to buy another PSU and power the 980Ti with it. The gt120 will allow the boot screen. After the boot, the 980Ti takes over...

 

[babyjoe]

I have a gt120 and 980Ti in my 4,1 flashed to 5,1. The easiest way for me to power the 980Ti is to buy another PSU and power the 980Ti with it. The gt120 will allow the boot screen. After the boot, the 980Ti takes over...

Ok, thanks! What kind of a PSU do you recommend?
[doublepost=1506506950][/doublepost]

Reading some of the feedback with High Sierra, it looks like you need it to install the new OS.

So, if I understand i correctly, you only need a boot screen when you want to update the OS. If I go with the GTX 980 ti and nothing more I could just save my old GPU for updating issues?
[doublepost=1506506993][/doublepost]

This question is asked over and over. Some swear they don't need it. Me, on the other hand need and use it. I would feel lost without it.

Lou

What do you use for?
[doublepost=1506507102][/doublepost]

Almost never for most people. But some people may want it for single user mode etc.

What is a "single user mode"?

You seem certain that I really could use a boot screen option, why am I in need of that?