real life experience with rx570 cross fire?

[dfsgsfa]

seeing alot of used rx570 4gb under $65

since i already got one, thinking of trying xfire

 

rvam, i think 4gb is enough for 1080p

used gtx1070 is around $180

psu should be enough, tx550m for r7 1700 ,100w + 2x 570 , 2x 140w-180w

 

what to expect for a xfire 570 in a game  not capable for worse case?

 

[SavageNeo]

3 minutes ago, dfsgsfa said:

what to expect for a xfire 570 in a game  not capable for worse case?

worse case is that in most games the performance is actually worse. sli is de3ad basically

 

just get the used 1070

[shoutingsteve]

Avoid the crossfire and SLI thing... It had it's time, now it is over.  Too many problems for too little results.

[Haro]

12 minutes ago, dfsgsfa said:

used gtx1070 is around $180

And that will probably perform better. 

Cf and sli don't scale well and bring little to no performance benifits. 

[dfsgsfa]

33 minutes ago, TofuHaroto said:

Cf and sli don't scale well and bring little to no performance benifits. 

could i expect 30% improvement?

some say its similar to vega 56

[SavageNeo]

6 minutes ago, dfsgsfa said:

could i expect 30% improvement?

some say its similar to vega 56

no

[Haro]

10 hours ago, dfsgsfa said:

some say its similar to vega 56

Sadly, in most if not, all  cases, no.

[porina]

 

I bought 3x RX 580 to try 3-way crossfire to get the above 3DMark Steam achievement. In short, Crossfire was a horrible broken mess, and probably still is. Save yourself the pain and suffering and get a single faster card if you need a performance improvement.

 

The only good case remaining for multiple GPUs in one system is if you do compute, like folding@home. This is without crossfire so it works ok generally, as it is multiple single cards.

[Godspeed Tech]

On 8/15/2020 at 2:53 AM, porina said:

 

I bought 3x RX 580 to try 3-way crossfire to get the above 3DMark Steam achievement. In short, Crossfire was a horrible broken mess, and probably still is. Save yourself the pain and suffering and get a single faster card if you need a performance improvement.

 

The only good case remaining for multiple GPUs in one system is if you do compute, like folding@home. This is without crossfire so it works ok generally, as it is multiple single cards.

Did you get 3 way crossfire working?

I'm trying to do the same thing with a MSI Z97 Gaming 5 board right now

 

3x RX 580 8GB Sapphire Nitro +

 

Problem I'm having is that Radeon software only sees 2 of the cards.

3D Mark sees all 3 but will only run them in 2 way crossfire, I can only assume is due to a software issue

 

Were you using the latest Radeon software or something older?

[porina]

22 minutes ago, Godspeed Tech said:

Did you get 3 way crossfire working?

I'm trying to do the same thing with a MSI Z97 Gaming 5 board right now

Yes, but I did it on X99 platform. That runs 3 GPUs off CPU lanes, even with a 28 lane CPU, split 16x, 8x, 4x. Your problem may be that you're using a consumer platform, so you only get two 8x from CPU at best, and the 3rd is on chipset lanes. I don't know if that is allowed or not.

 

22 minutes ago, Godspeed Tech said:

Were you using the latest Radeon software or something older?

https://www.3dmark.com/fs/14498888

 

Still got the result saved online, at above. You can try working out driver versions from there. It was probably the latest at the time of running.

 

[Godspeed Tech]

40 minutes ago, porina said:

Yes, but I did it on X99 platform. That runs 3 GPUs off CPU lanes, even with a 28 lane CPU, split 16x, 8x, 4x. Your problem may be that you're using a consumer platform, so you only get two 8x from CPU at best, and the 3rd is on chipset lanes. I don't know if that is allowed or not.

 

https://www.3dmark.com/fs/14498888

 

Still got the result saved online, at above. You can try working out driver versions from there. It was probably the latest at the time of running.

 

You're right, looking further into it, I am having a PCIe lane limitation. My Z97 will do either (16x) or (8x 8x) or (8x 4x 4x)

while it DOES technically support 3 way crossfire, it would be with the older variety of CF that used a bridge as bridged crossfire can work fine on 4x

But the RX 580 and other bridgeless cards require 8x at each slot

 

There are some Z97 boards that use a PLX chip to get those additional lanes by sharing bandwidth with other slots, but they carry a hefty premium. For RX cards, the crossfire requirements are the same as SLI requirements as SLI also requires 8x minimum. So if the board supports SLI 3/4 way, it'll also run Rx series bridgeless XFire

 

X99 seems to have the most success, but since I'm not leaving things at "I figured it out;" 

Here's a list of LGA1150 Haswell 3/4 way boards:
 
Z87:

-Asus Maximus VI Extreme
-Asrock Extreme11 & Extreme9
-Gigabyte G1.Sniper 5
-Gigabyte OC Force
-Msi Xpower
 
Z97:
 
-Asus Maximus VII Extreme
-Asrock Extreme9
-EVGA Z97 Classified
-Gigabyte G1 Gaming & Wifi BK (they dropped the "sniper" name)
-MSI XPower

 

So now I have to decide if I want to grab another board, or maybe get lucky with a bunch of cheap R9 cards 

[porina]

2 minutes ago, Godspeed Tech said:

You're right, looking further into it, I am having a PCIe lane limitation. My Z97 will do either (16x) or (8x 8x) or (8x 4x 4x)

while it DOES technically support 3 way crossfire, it would be with the older variety of CF that used a bridge as bridged crossfire can work fine on 4x

But the RX 580 and other bridgeless cards require 8x at each slot

That doesn't agree with my used configuration. As said my system then was running 16x, 8x, 4x. The difference is these are CPU lanes, not chipset, so that might be the thing?

[Godspeed Tech]

1 minute ago, porina said:

That doesn't agree with my used configuration. As said my system then was running 16x, 8x, 4x. The difference is these are CPU lanes, not chipset, so that might be the thing?

Hmmm, it's hard to say. I know boards with PLX chips would use bandwidth from other slots to sort of fudge some extra lanes. The chipset definitely plays a big role. While the 3rd May be a 4x slot, it could potentially have been borrowing bandwidth from somewhere else 

 

Maybe I'll check the driver you were using and see if I can't find it and test it. I know a lot of support has been dropped for newer stuff