2 x Sapphire RX 580 Nitro+ 8GB - Benchmark?

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
Hello,

I bought a couple of RX 580's pretty cheap and will probably sell one off them.

I switched from a Gigabyte GTX 970 G1 so I got everything working with cables...

In terms of power (1 x 8-pin) I thought it would be okay to plug both the cards in and see if I could run both.

My bet is that I will get a shutdown with prober benchmark software. I just ran a Unigine Heaven test in osx and got the same score as with one card.

Is it because of Heaven, osx instead of windows or maybe drivers that number two card doesn't pitch in?

Any ideas? :)

IMG_0527.JPG
 
Last edited:

bsbeamer

macrumors 68030
Sep 19, 2012
2,634
1,285
First troubleshoot: actually plugging power in for all power pins on the GPUs. Image looks like there are "open" 6-pins on each GPU that are not connected to anything...
 

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
I have read a lot of places that with the Nitro+ model the 6-pin is only for OC. It has no real function in every day use according to many forums...
 

bsbeamer

macrumors 68030
Sep 19, 2012
2,634
1,285
If you are troubleshooting, ensuring you are providing all power is the first place to troubleshoot with any/all GPUs. Good luck with your setup.
 

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
It booted fine and second card was registred in "system information".

In my mind it doesn't quite make sense that Heaven didn't utilize both GPU's. My guess is that OSX can do crossfire...
 

spidertnt

macrumors member
Aug 11, 2014
32
20
How did you get it to fit the in first slot ....mine was so tight against the CPU cage ..i moved it to the second slot.
 

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
How did you get it to fit the in first slot ....mine was so tight against the CPU cage ..i moved it to the second slot.
Had the same problem as you...

Be sure NOT to lay down your Mac when inserting the GPU. Place it upright and insert the GPU on the CPU cage and slide it in. When you feel that it has contact with the PCI-E slot be sure to slightly push the GPU towards the back of the Mac.

That should give the "perfect fit" so it's optimal with the "support panel" for all PCI-E expansions.
 

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
Really like this card ....plays Wolfenstein II at 2k no problems
Well as far as I know that card is probably one of the best mid-range cards. I don't use it for gaming but had to switch my GTX 970 out because of Mojave :)

To be honest I'm quite glad that I made the switch. Just works a bit easier with a OOTB card. No need for two GPU's and Nvidia Web Drivers...
 
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bsbeamer

macrumors 68030
Sep 19, 2012
2,634
1,285
How did you get it to fit the in first slot ....mine was so tight against the CPU cage ..i moved it to the second slot.
You can try removing the two backplate screws on the PCIe side to see if it makes a difference in Slot 1. Basically was the magical fix to getting a Sapphire Pulse RX 580 8GB in slot 1 for my MP5,1 and being able to use the other three PCIe slots.

Photos and more in this thread:
https://forums.macrumors.com/threads/mp5-1-sapphire-pulse-rx580-8gb-spacer-wedge-for-pcie-slot-2.2134562/page-2#post-26413743
 
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h9826790

macrumors G5
Apr 3, 2014
12,985
5,863
Hong Kong
Hello,

I bought a couple of RX 580's pretty cheap and will probably sell one off them.

I switched from a Gigabyte GTX 970 G1 so I got everything working with cables...

In terms of power (1 x 8-pin) I thought it would be okay to plug both the cards in and see if I could run both.

My bet is that I will get a shutdown with prober benchmark software. I just ran a Unigine Heaven test in osx and got the same score as with one card.

Is it because of Heaven, osx instead of windows or maybe drivers that number two card doesn't pitch in?

Any ideas? :)

View attachment 830513
If I read your picture correctly, your config is 100% sure will hit the shutdown protection if you can fully utilise both GPU.

It seems you have a dual mini 6pin to single 8pin cable. And then use a 8pin female to dual 6+2 cable to power two Nitro+ RX580.

Only plug in the 8pin is OK for this card as per Sapphire's manual, and many users confirm this already. So this is not a problem.

However, the Nitro+ will draw really close to 150W from the 8pin when under real high stress. And many apps can easily make it draw ~120W from the 8pin.

So, what you are doing is combining two mini 6pins together. And make it a single 240W power source for two Nitro+ RX580.

When you running Ungine Heaven, it's an OpenGL benchmark, and no Crossfire support in macOS. So, only the RX580 that connected to the monitor is working. This is why your multi GPU benchmark is same as single GPU benchmark. Because that benchmark software cannot utilise multi GPU.

In this case, the RX580 that is working hard may draw ~120W from the 8pin, and the other RX580 may only draw ~10W. So, 130W in total for both mini 6pin. Easy job, no problem at all.

But if you try to run something like Luxmark. Both GPU will work together, and each of them will draw really close to 120W from the 8pin. In that case, the power draw may be already high enough to trigger the shutdown protection.

And if you connect two monitors, one monitor for each card. And then run two Furmark (one on each monitor). This will make both cards draw 150W each from the 8pin, and 100% guarantee will shut down your cMP.

Also, if you run Unigine Heaven in Windows with Crossfire enabled, that may also good enough to trigger the shutdown protection.

Anyway, what you plan to do with this setup? If just something like FCPX, most likely will be OK.
 
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MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
If I read your picture correctly, your config is 100% sure will hit the shutdown protection if you can fully utilise both GPU.

It seems you have a dual mini 6pin to single 8pin cable. And then use a 8pin female to dual 6+2 cable to power two Nitro+ RX580.

Only plug in the 8pin is OK for this card as per Sapphire's manual, and many users confirm this already. So this is not a problem.

However, the Nitro+ will draw really close to 150W from the 8pin when under real high stress. And many apps can easily make it draw ~120W from the 8pin.

So, what you are doing is combining two mini 6pins together. And make it a single 240W power source for two Nitro+ RX580.

When you running Ungine Heaven, it's an OpenGL benchmark, and no Crossfire support in macOS. So, only the RX580 that connected to the monitor is working. This is why your multi GPU benchmark is same as single GPU benchmark. Because that benchmark software cannot utilise multi GPU.

In this case, the RX580 that is working hard may draw ~120W from the 8pin, and the other RX580 may only draw ~10W. So, 130W in total for both mini 6pin. Easy job, no problem at all.

But if you try to run something like Luxmark. Both GPU will work together, and each of them will draw really close to 120W from the 8pin. In that case, the power draw may be already high enough to trigger the shutdown protection.

And if you connect two monitors, one monitor for each card. And then run two Furmark (one on each monitor). This will make both cards draw 150W each from the 8pin, and 100% guarantee will shut down your cMP.

Also, if you run Unigine Heaven in Windows with Crossfire enabled, that may also good enough to trigger the shutdown protection.

Anyway, what you plan to do with this setup? If just something like FCPX, most likely will be OK.
Thank you for the clear answer. Kind of what I thought myself.

The thing is I just bought 5 of these cards pretty cheap and wanted to have a little fun :)

I have no use of more than 1 card in my Mac Pro. Only switched to RX 580 from GTX 970 because of Mojave and general convenience. Just wanted to see if I could fit two of them inside the case before selling remaining cards.

Completely different question: Is it possible to upload a sound file in this forum?

Thanks again for your respons!
 

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
Will I then be able to upload it using the "media" button or?

It's because of another question/problem I asked the other day in this thread:

https://forums.macrumors.com/threads/rx-580-mojave-install-no-screen.2175381/#post-27230692

Read from post #10 - It's about my PSU and I have made a recording of the sound that maybe could help in the proces of determine what the problem is...

I have an idea about the problem and planning to take the PSU out tomorrow and try to fix it.

...but maybe the soundfile could help if other people heard it :)
 

h9826790

macrumors G5
Apr 3, 2014
12,985
5,863
Hong Kong
Will I then be able to upload it using the "media" button or?

It's because of another question/problem I asked the other day in this thread:

https://forums.macrumors.com/threads/rx-580-mojave-install-no-screen.2175381/#post-27230692

Read from post #10 - It's about my PSU and I have made a recording of the sound that maybe could help in the proces of determine what the problem is...

I have an idea about the problem and planning to take the PSU out tomorrow and try to fix it.

...but maybe the soundfile could help if other people heard it :)
Just upload it as a "File" (the button next to "Post Reply")
 

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
Yeah, sounds like from the PSU.
Have you heard anything like it before? Like described in the other topic?

On one hand I'm a bit concerned but on the other I have seen no other problems that could be related to the PSU. It's just a really annoying sound if it can be avoided...

...and as far as I remember I was told that it's NOT a "normal" sound :(
 

h9826790

macrumors G5
Apr 3, 2014
12,985
5,863
Hong Kong
Have you heard anything like it before? Like described in the other topic?

On one hand I'm a bit concerned but on the other I have seen no other problems that could be related to the PSU. It's just a really annoying sound if it can be avoided...

...and as far as I remember I was told that it's NOT a "normal" sound :(
AFAIK, that's quite normal indeed.

And from what I've read so far.

220V-240V power source has higher chance can hear this (there was a MR member move from a 110V country to a 220V country, and he suddenly can hear this sound).

Anti surge device / UPS may help to reduce this sound.
 

MikkelAD

macrumors regular
Original poster
Feb 17, 2018
118
7
AFAIK, that's quite normal indeed.

And from what I've read so far.

220V-240V power source has higher chance can hear this (there was a MR member move from a 110V country to a 220V country, and he suddenly can hear this sound).

Anti surge device / UPS may help to reduce this sound.
Great with that extra info!

I will try to fix it and come back if I succeed :)