Using 2 Video Cards vs. 1 for 3 displays

Jigga Beef

macrumors regular
Original poster
Jan 11, 2009
176
3
Philadelphia, Pa
I currently have 3 X 28 inch 4K Samsung monitors power off a single AMD Radeon RX 580. All of them using with display port - display port.


I have 2 X ATI Radeon 5770 1GB VRAM just sitting around collecting dust and 1 spot open in my PCI cards. I would need to use Display port - Mini Display port to connect to the 5770.


Would I see any benefit or performance increase by installing the 5770 and hooking 1 monitor up to it?
 

tsialex

macrumors 604
Jun 13, 2016
7,667
8,373
Brazil
I currently have 3 X 28 inch 4K Samsung monitors power off a single AMD Radeon RX 580. All of them using with display port - display port.


I have 2 X ATI Radeon 5770 1GB VRAM just sitting around collecting dust and 1 spot open in my PCI cards. I would need to use Display port - Mini Display port to connect to the 5770.


Would I see any benefit or performance increase by installing the 5770 and hooking 1 monitor up to it?
How do you gonna feed power to the HD 5770? RX-580 needs the two PCIe AUX power. BTW, HD 5770 only works up to 10.13.6.
 

G5isAlive

macrumors 6502a
Aug 28, 2003
868
1,157
How do you gonna feed power to the HD 5770? RX-580 needs the two PCIe AUX power. BTW, HD 5770 only works up to 10.13.6.
Technical considerations aside on implementation... (you can get an external power supply)... the question remains, would this help performance? I would love to know that answer.
 

tsialex

macrumors 604
Jun 13, 2016
7,667
8,373
Brazil
Technical considerations aside on implementation... (you can get an external power supply)... the question remains, would this help performance? I would love to know that answer.
I doubt that the HD 5770 will help in any way the RX-580 and even if helps, will warrant to do all the power mods needed to feed a card that stops working at 10.13.6?
 

Jigga Beef

macrumors regular
Original poster
Jan 11, 2009
176
3
Philadelphia, Pa
Well that seems to settle it if its not support its not worth it.

I thought the Logic board gave me 2 places to get power from and I am only using one with the current card.
 

tsialex

macrumors 604
Jun 13, 2016
7,667
8,373
Brazil
Well that seems to settle it if its not support its not worth it.

I thought the Logic board gave me 2 places to get power from and I am only using one with the current card.
If you are using only one with a RX-580, you will damage your logic board.

75W from the slot plus 75W from the PCIe AUX will get nowhere near the ~230W of maximum power consumption of a RX-580.
 
Last edited:

G5isAlive

macrumors 6502a
Aug 28, 2003
868
1,157
I doubt that the HD 5770 will help in any way the RX-580 and even if helps, will warrant to do all the power mods needed to feed a card that stops working at 10.13.6?
Two separate issues... whether its worth it and whether it would help. I really was only interested in the later.. as I have an open slot in my Mac Pro and have often wondered if two cards were better than one. And actually, for a variety of reasons I don't plan to upgrade that Pro past 10.12. But as indicated, I am not interested in debating is it worth it.
 

tsialex

macrumors 604
Jun 13, 2016
7,667
8,373
Brazil
Two separate issues... whether its worth it and whether it would help. I really was only interested in the later.. as I have an open slot in my Mac Pro and have often wondered if two cards were better than one. And actually, for a variety of reasons I don't plan to upgrade that Pro past 10.12. But as indicated, I am not interested in debating is it worth it.
Two cards are better than one, but not in a disparate situation like HD 5770 and RX-580. Look for tests with dual GTX 1080, people have tested it extensively some time ago.
 
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thornslack

macrumors 6502
Nov 16, 2013
410
164
I believe the general consensus is running additional monitors on a gpu may increase temperature on the card by a slim margin but has almost no performance impact.
 
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devon807

macrumors 6502
Dec 31, 2014
367
94
Virginia
I did this with my 2 RX 580's. Having them attached to different displays actually caused quite a bit of UI lag. The only difference being I was trying to run 2x 30 inch ACD and one 28 Inch 4k Samsung
 
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