GTX 980 Ti for Mac Pro 4,1 recommendations

[pastrychef]

I've got a 5,1 and assuming that power is not an issue (planning on getting a separate power supply)
1. is there a real difference between an overclocked 980 and a 980ti ?
2. if I install an overclocked 980 (or any oc card) does it work at full speed automatically or do I need to install the web drivers so it goes full speed? I am strictly using this on OSX, I don't game at all.

background, Ill be using this for Adobe Lightroom, Photoshop .. maybe Primere and FinalCut. Really looking for 4k and 5k video at this point

Dave

1. The GTX 980 Ti is considerably faster. Even if your GTX 980 is overclocked, a GTX 980 Ti still faster.

2. It depends. If the overclock is done on the firmware level, it will work at full speed. You will need the Nvidia web drivers for macOS whether your card is overclocked or not.

 

[webbp]

1. If I power the card with the two mini 6-pin only, which version would work best? (if at all..)

I highly recommend not running a 980 Ti using only PCIe power with one 6-pin to mini 6-pin and one 8-pin to mini 6-pin. Maybe it's ok for graphical or gaming uses which don't push the card to card 100% for more than a few seconds at a time, but not for applications that use the card near 100% for sustained periods, e.g., machine learning. I killed the backplane of my Mac Pro 4,1 flashed to 5,1 like this.

 

[iAssimilated]

I am planning on putting a regular GTX 980 (purchased from MVC) in a 2012 Mac Pro and installing linux on it to make a gaming rig. The description states I will receive 2 modular PCIe power cables with the card. Is that sufficient to power this card or do I need to think about getting something else?

 

[tsialex]

I am planning on putting a regular GTX 980 (purchased from MVC) in a 2012 Mac Pro and installing linux on it to make a gaming rig. The description states I will receive 2 modular PCIe power cables with the card. Is that sufficient to power this card or do I need to think about getting something else?

Depends. The reference model of this card has a power usage that is very similar of some Apple recommended GPUs (like Sapphire Pulse RX 580), but not every manufacturer use the same power settings with the card firmware and this could be one of the cards that are over the line.

Even with cards that go a little over the line, it's your usage that makes it safe or not. If you are a casual user, you probably won't damage the backplane overtime, but if you are constantly using the card at full throttle, you need to think in a better way to power it, Pixla's mod for example.

 

[iAssimilated]

Depends. The reference model of this card has a power usage that is very similar of some Apple recommended GPUs (like Sapphire Pulse RX 580), but not every manufacturer use the same power settings with the card firmware and this could be one of the cards that are over the line.

Even with cards that go a little over the line, it's your usage that makes it safe or not. If you are a casual user, you probably won't damage the backplane overtime, but if you are constantly using the card at full throttle, you need to think in a better way to power it, Pixla's mod for example.

I'll only be using the card occasionally to play games that don't run on macOS. Although, the card arrived today and it is actually a GTX 980 Ti

It has a 6-pin and 8-pin power connector. I do have a dual mini 6-pin to 8-pin adapter cable, but the card did come with two mini 6-pin to 8-pin (6+2) cables. Not sure if this is safe to use or not.

I'll look into the Pixla's mod.

EDIT #1: The Pixla's mod looks intense! One thing I am not is an electrician.

EDIT #2: The actual card is EVGA GeForce TGX 980 Ti 06G-P4-4995-KR 6GB SC+ GAMING w/ACX 2.0+

 

[tsialex]

I'll only be using the card occasionally to play games that don't run on macOS. Although, the card arrived today and it is actually a GTX 980 Ti

It has a 6-pin and 8-pin power connector. I do have a dual mini 6-pin to 8-pin adapter cable, but the card did come with two mini 6-pin to 8-pin (6+2) cables. Not sure if this is safe to use or not.

I'll look into the Pixla's mod.

You can run FurMark to see if the card can trigger the SMC power overconsumption shutdown, but even if it cannot, this is one of the GPUs that can damage the backplane PCB power lines in the long run with sustained overconsumption.

 

[webbp]

If you're running Windows, you can use software to decrease power consumption. Or hire a computer hardware tech to do Pixla's mod.

 

[webbp]

You can run FurMark to see if the card can trigger the SMC power overconsumption shutdown

Maybe my backplane was just coincidentally on its last legs, but I killed it specifically by replacing the stock GT 120 with a 980 Ti and running furmark for about an hour until SMC power overconsumption (or perhaps overheating) caused shutdown. The machine then gave kernel panics with increasing frequency for a week, then died completely.

 

[tsialex]

Maybe my backplane was just coincidentally on its last legs, but I killed it specifically by replacing the stock GT 120 with a 980 Ti and running furmark for about an hour until SMC power overconsumption (or perhaps overheating) caused shutdown. The machine then gave kernel panics with increasing frequency for a week, then died completely.

I wouldn't run FurMark for more than 10~15 minutes with a GPU that is 8+6pin or any GPU that is know to be over/around the total 225W power consumption.

Even with the Sapphire Pulse RX580 that Apple recommends, 183W + PowerPlay that will get you ~228W, you can trigger the SMC power shutdown with FurMark.

Btw, remember that this 228W of the Sapphire Pulse is not equalised over all the power lines, the PCIe slot only provides around 45W and the rest of power usage is not equally divided between AUX A and AUX B.

 

[iAssimilated]

You can run FurMark to see if the card can trigger the SMC power overconsumption shutdown, but even if it cannot, this is one of the GPUs that can damage the backplane PCB power lines in the long run with sustained overconsumption.

If you're running Windows, you can use software to decrease power consumption. Or hire a computer hardware tech to do Pixla's mod.

Do I have any other options (other than the Pixla's mod)?

I do have spare Sapphire Pulse Radeon RX 580 on hand, but was hoping to use an Nvidia card to see the differences. Apparently I got the wrong Nvidia card.

 

[iAssimilated]

I wouldn't run FurMark for more than 10~15 minutes with a GPU that is 8+6pin or any GPU that is know to be over/around the total 225W power consumption.

Even with the Sapphire Pulse RX580 that Apple recommends, 183W + PowerPlay that will get you ~228W, you can trigger the SMC power shutdown with FurMark.

Apparently I have all the wrong cards... lol. Is this due to the age of the 2012 Mac Pro?

 

[tsialex]

Do I have any other options (other than the Pixla's mod)?

External GPU PSU or powering the 6-pin with two SATA power lines for the 980Ti

Edit: external PSU, not GPU.

 

[tsialex]

Apparently I have all the wrong cards... lol. Is this due to the age of the 2012 Mac Pro?

It's a design from 2008, early-2009 was released March-2009, totally different GPUs back then.

 

[tsialex]

I do have spare Sapphire Pulse Radeon RX 580 on hand.

eVGA PowerLink can be used to safely equalise the power consumption between the two AUX power connectors with a Sapphire Pulse RX-580 without any other mods. Unless you have a very poor/tired power circuit with your Mac Pro backplane, you won't have any problems.

 

[iAssimilated]

External GPU or powering the 6-pin with two SATA power lines for the 980Ti

I didn't know eGPUs work on the older Mac Pros.

It's a design from 2008, early-2009 was released March-2009, totally different GPUs back then.

Makes total sense.

eVGA PowerLink can be used to safely equalise the power consumption between the two AUX power connectors with a Sapphire Pulse RX-580 without any other mods. Unless you have a very poor/tired power circuit with your Mac Pro backplane, you won't have any problems.

Can that do the same thing for the 980 Ti? I assume not since you didn't mention it. Apparently my grand plan isn't so grand after all.

Thank you for all you insight into this matter! I'm not sure what to do now, but I have plenty to think about.

 

[tsialex]

I didn't know eGPUs work on the older Mac Pros.

My bad, external PSU, not GPU.

You can make eGPUs work via Thunderbolt with a MP5,1, but it's another can of worms and let's forget about that.

Can that do the same thing for the 980 Ti?

Probably so for a very casual usage, if the PowerLink is even compatible, since some of the eVGA ACX cards have weird power connector arrangements, but not for heavy use.

 

[iAssimilated]

Unless you have a very poor/tired power circuit with your Mac Pro backplane, you won't have any problems.

Forgive my ignorance on this, but I am relatively new to Mac hardware (only been using them for about four years), when you refer to the power circuit on the backplane, is this a controller chip on the motherboard handling the power feed from the power supply?

Up until I switched to Macs I built my own PC rigs and pretty much everything (other than the motherboard) was powered directly from the PSU. Is the cable shown in the Pixlas Mod coming from the power supply to the backplane (just trying to fully understand)?

 

[tsialex]

is this a controller chip on the motherboard handling the power feed from the power supply?

Several, power is totally managed with a Mac Pro. The brain of the design is the SMC micro controller, the Renesas F2117TE20H H8S/2117V TQFP-144pin on the backplane. There are lot's of amperage sensor CIs all over.

Up until I switched to Macs I built my own PC rigs and pretty much everything (other than the motherboard) was powered directly from the PSU. Is the cable shown in the Pixlas Mod coming from the power supply to the backplane (just trying to fully understand)?

Pixla's mod is exactly like a PC, you totally bypass the backplane power circuit and go directly to the PSU. It's a piggyback on the PSU connection to the backplane.

 

[iAssimilated]

Thank you for the details!

I guess I should start to wrap my head around doing the Pixlas Mod... at this point it is between ruining the PSU power cable vs. frying a backplane.

Option #3, I do have a spare eGPU enclosure that maybe I can modify to provide power to the 980 Ti.

Choices! ?

 

[tsialex]

Thank you for the details!

I guess I should start to wrap my head around doing the Pixlas Mod... at this point it is between ruining the PSU power cable vs. frying a backplane.

Option #3, I do have a spare eGPU enclosure that maybe I can modify to provide power to the 980 Ti.

Choices! ?

I'd start with a eVGA PowerLink and RX 580 until you get a better grasp on what to do to safely power the 980Ti.

 

[iAssimilated]

I agree. This whole project is more of a "I have the spare equipment and want to see if it can be done", not a "I want to destroy a perfectly good 2012 Mac Pro because I can."

Again, thank you for all your assistance with this matter! I've learned something today and that alone has made this all worth it so far.

 

[webbp]

eVGA PowerLink can be used to safely equalise the power consumption between the two AUX power connectors with a Sapphire Pulse RX-580 without any other mods

Can that do the same thing for the 980 Ti?

I got an EVGA PowerLink hoping to use it with my 980 Ti, but the 980 Ti I got had one 6-pin and one 8-pin socket, whereas the PowerLink has two 8pin male connectors, so no go without additional adapter cables. I hadn't considered using it with my RX 580, though. Thanks for the idea, @tsialex !

 

[tsialex]

I got an EVGA PowerLink hoping to use it with my 980 Ti, but the 980 Ti I got had one 6-pin and one 8-pin socket, whereas the PowerLink has two 8pin male connectors, so no go without additional adapter cables. I hadn't considered using it with my RX 580, though. Thanks for the idea, @tsialex !

My eVGA PowerLink kit has an additional connector for 8+6 pin cards, I can take a picture this weekend.

No need to take a picture, look at this picture from eVGA page:

https://br.evga.com/products/product.aspx?pn=600-PL-2816-LR

 

[webbp]

What editing the GPU BIOS to limit max power consumption to 75W from the slot and 75W from each connector, and max 225W?

[Guide] Definitive Maxwell II (2) vBIOS Modding

How To: vBIOS mod your Maxwell 2 based GPU Introduction Welcome my minions to another guide bought to you by yours truly, today I will be showing you how to tweak the snot out of your Maxwell II based GPU. They may be a little older now, but they still have better IPC than Pascal, meaning...

www.xtremesystems.org

This would require booting into Windows to make the edits. I guess this would also cause the card to slow down sometimes, or at least not work as fast as it could given more power, but that beats frying a backplane. Just a guess, but also underclocking and/or turning off boost might provide a more stable experience.

PS: From the above link, it looks as though the default for at least some 980 GPUs is to permit it to draw up to 159W from a single PCIe power connector for brief bursts!

 

[tsialex]

What editing the GPU BIOS to limit max power consumption to 75W from the slot and 75W from each connector, and max 225W?

[Guide] Definitive Maxwell II (2) vBIOS Modding

How To: vBIOS mod your Maxwell 2 based GPU Introduction Welcome my minions to another guide bought to you by yours truly, today I will be showing you how to tweak the snot out of your Maxwell II based GPU. They may be a little older now, but they still have better IPC than Pascal, meaning...

www.xtremesystems.org

This would require booting into Windows to make the edits. I guess this would also cause the card to slow down sometimes, or at least not work as fast as it could given more power, but that beats frying a backplane. Just a guess, but also underclocking and/or turning off boost might provide a more stable experience.

PS: From the above link, it looks as though the default for at least some 980 GPUs is to permit it to draw up to 159W from a single PCIe power connector for brief bursts!

I don't like it, this is a card that needs a Pixla's mod. Even more so, you paid it to be flashed and then you gonna mod the VBIOS and then invalidate the flashing service?