Graphics Cards

[tikwid]

Just decided to try adding a second GPU to my system. My new card is an RX 580 while the old one is an RX 480. The RX 580 is in the primary slot. Everything runs fine in single GPU mode but if I boot up a game like Overwatch while crossfire is enabled in the global settings, the system hard freezes (no BSOD) as soon as the main menu loads (where there are 3D graphics being rendered). Is this a power supply issue? I tried making sure both cards are seated properly and the power connections are solid. It's 850 Thermaltake PSU. Any suggestions?

[dstmnd89x]

Are there any other games where it doesn't lock up? I'm not familiar with Overwatch but multi-GPU is handled differently across game engines. The cards should work but the only thing I would advise is to make sure that each card is on its own +12V rail, if the PSU has a split rail design. Reason being, the amperage will be divided between rails which can only provide a certain amount of current to each GPU. If there are two on a single rail that is split from the total wattage, then you might experience issues like you have described.

[tikwid]

Pretty sure it's a single rail. Is my PSU still the most likely culprit? Should I just buy a crossfire certified PSU? Both PCI slots and cards work in single GPU mode and my motherboard is supposed to be crossfire compatible. All temperatures appear normal. The system just hard freezes with no BSOD, video output image stuck on monitor and sound cuts off, some of the fans seem to turn off or get quieter after the freeze too. Those are the symptoms I'm getting when it freezes.

[dstmnd89x]

If it's single rail then I wouldn't worry about the cards getting power, as that should be plenty. Some games are better optimized for multi-GPU than others, that's true, but I might suggest browsing some game-specific communities and patch notes just to be sure that some more recent update broke crossfire support or something. That, I am familiar with; is one of the problems I no longer use multi-GPU. Most of the time it either works or doesn't, or it eventually gets broken at some point once patches start rolling out.

[pokester]

An RX 580 and RX 480 do not crossfire together. They can work together in multi-gpu under Direct X 12. However for that to happen the game engine has to support multi-gpu in Direct X 12. To my knowledge the only game in existence currently that supports multi gpu is Ashes of Singularity. No telling when this will have wide spread support, but will be nice when it does at it will even allow you to mix and match cards from both red and green teams if all works as they planned. So bottom line you are trying to do something that can't be done. Lucking one RX 580 is overkill for Overwatch so it should not be an issue. I would utilize that RX 480 in another build if I were you.

[tikwid]

Thanks for trying to help, but you don't seem to know your stuff. There are successful benchmarks posted by people using RX 580 + 480. They are essentially the same GPU. The only downside is that the RX 580's individual output would be slightly downgraded by the RX 480 in a crossfire setup which I can live with. It's also not overkill for a game like Overwatch if you are trying to achieve max frame rate on a 144hz monitor like I am. Are there any AMD experts that can weigh in?

[pokester]

No I know my stuff, the people cross firing them with good results are often loading RX 580 bios on those 480s and that is something no manufacturer or AMD supports. Never said it cant be forced to be done. However even when done it will force both cards to operate at the lower common denominator. Even when you get it successfully launch you often have sync issue, screen anomalies of artifacts and such and weird flickers are all symptoms of Crossfire not working properly. These can be from the cards not marrying well (ie not same series), the drivers or the game engine not being optimized. Then you add to that that almost no game in the last couple years has decent crossfire support There have been huge amounts of complaints of crossfire not working well in drivers over the last year. Seeing successful benchmarks doesn't mean across the board great success with crossfire by any means, it just means they completed a benchmark.  Also telling someone trying to help you they don't know their stuff because it isn't what you want to hear is rude. Sure someone else will likely send you down the rabbit hole and have you chasing your tail and you may or may not find a decent result. Lots of things can theoretically work it doesn't equal a positive experience.  Who knows, me I'm only telling you what is officially supported not what  and will likely give you the best trouble free support. That has always, without exception on both teams been a single card solution from the beginning that has the power to do what you want. Dual or more cards has always been a when the stars align perfectly scenario. Even in the best cases there have still been trade offs that make it not worth it. This is why you almost always see most tech sights recommend the right single card to meet your needs.  Now while the chip between the two is the essentially the same, the cards are not, they have different speed and power requirements. Most original reviews claimed them to be virtually the same because they were the same chip just overclocked. In reality very few RX 580 sold are even reference design they have been greatly overclocked from reference on different boards with different power requirements, so yes they are not the same. Being able to turn something on in the software doesn't make it a good fit or a pleasant experience. But we all like to hear what we are looking for I like that. In the future maybe try to loose the insults. If you bought a 580 expecting a high refresh rate solution to meet your refresh needs, when married with an older card, you likely misspent your money. I sure as heck do know what I am talking about and do wish you the best of luck.

Sorry for the edit I accidentally hit reply on my tablet before being done.

[tikwid]

Not trying to insult and I appreciate the help but some quick research will tell you the RX 580 and 480 are the almost exactly same card on the same architecture except 580s tend to be faster clock speeds. The clock speeds between my two cards are almost identical too, so my 580 wouldn't be too downgraded either. The problems you're mentioning are with Crossfire in general but 580 and 480 are compatible without flashing them, etc. You don't always have to have the same card to do crossfire, AMD's drivers are supposed to automatically match the faster card to the slower card for you. A quick google search will bring up videos of other people doing the same thing as me. I'm trying to determine if one of my other pieces of hardware is causing a conflict or if it's some kind of software issue.

[pokester]

and I didn't say any of those things you attributed to me. I didn't say you had to flash them. I said that those that have the most stable success have done that. I explained the differences in the 2 lines of cards thoroughly which you still allude to like I never researched. I own one and promise I do the research and I help people here every day.  Most people wouldn't want to take an upwards of 25% performance hit on a single card to crossfire to a weaker card for what ultimately would be a handful of games at best that might benefit. Again almost not game in the last couple years has been crossfire optimized. Even the drivers themselves are questionably optimized for it anymore. They seem to have it going better on the Vegas now though. As far as the Mix and match on crossfire that has only been when on rebadges of the same product which the RX 580 is architecturley the same but again the card design is very different, and been between apu a lower end discreet cards. The lion share of Crossfire support has been the same cards only. The only other one I can thing of off the bat like the 480 580 situation was the HD 7950 7970 cards but again most didn't want to down clock the pair to the lower speed. The fact is that crossfire has never been a great solution as far as stability and not having graphical hiccups. So know I don't typically recommend it to anyone, and especially when they are not really meant to be paired to begin with. Again I never said you couldn't do it I recommend you don't and as you halve ready mentioned you are having issues. So do whatever you want, no issue for me, I am not the one here asking others advice the badgering them over it. If you are happy with the results great if you are not don't expect that the situation is going to improve, it probably isn't. Just because you can do something doesn't mean you should do something. Speaking of doing google searches you will see that Overwatch is known to have issues with dual graphics.

[colesdav]

Hi,

I do not think anyone is attacking you.
I agree Crossfire DX11 or MultiGPU DX12 s no good on games that do not support it.

Do you own any cards that can be Crossfired?
Have you run a Crossfire DX11 or DX12 multiGPU System?
Did you have a really bad experience with it?

There can be reasons where people may want to run multiple GPU for compute and take advantage of MultiGPU DX12 or Crossfire DX11 when it suits them.
A  matching card may come available to you at a low cost so you buy the matching card for a while to improve performance of the card you have already on the few supported titles that need it, rather than purchase a new GPU.

Even if you downclocked an RX580 by 5% to match an RX480 speed, pairing the two together on a supported AAA title with @ 90% scaling will be worth it for that particular title. Some supported titles run and scale really well.

I agree there have been some Crossfire disasters at launch, such as Tom Clancy's The Division, and others like Mass Effect Andromeda which was later withdrawn due to game optimization issues in Single GPU which caused problems in Crossfire DX11.

If you remember the launch of the RX 480, a premium experience in AAA games was promised for Crossfire DX11 and MultiGPU DX12 by AMD as dual RX480s were the only solution to combat the GTX1080 at the time. That premium experience was delivered for the most part on the new AAA titles I tested in the following years.

I have run an HD7970 OC 6GB in Crossfire with an R9 280X 3GB card for years. They are much more different than RX580/480.

The RX 580 is an RX480, with a BIOS that allows more power to be drawn so that it could perform better to keep up with a GTX1060 6GB at the expense of power efficiency. It is a refresh, essentially the same thing as an RX 480. There is very little difference between the two.  I have seen reviews where people are able to overclock an RX 480 to very close to the performance of an RX580. They can be crossfired together.

I have not purchased an RX480/580 since I prefer the performance of the Fiji cards and 4GB of HBM can handle >4GB GDDR5 textures well.
I was waiting for Vega to turn up.
I think Crossfire DX11 was de-emphasized with RX Vega 64 because its power consumption is already too high for 1 card.
I think HBM2 was slower (lower bandwidth) than expected, so had to overclock the RXVega 64 GPU to get near to GTX1080 performance.

DX12 MultiGPU and hopefully  Vulkan with MultiGPU must be the future. I do not think it will go away.
Multiple Small GPUs connected together on top of a substrate is the likely future of new GPU technology.
Smaller dies = better yields = lower cost and more flexibility for the manufacturer.

Bye.

[pokester]

I never said anyone was attacking me. I felt he was rude, never said attacking, I guess you said that? I only said that someone was putting words in my mouth that I didn't say and saying I don't know what I am talking about. As a system builder over the years not for myself but for our customers I have built well over 100 gaming systems where customers insisted on SLI or Crossfire. I don't know of one where anyone has ever been really happy with that in hind site. You rattle off a bunch of reasons why which I really already recognized in what I said and just was pointing out IMHO it isn't worth the grief and rarely satisfies expectations. If you have a different opinion awesome. Everyone is allowed to pick and choose the advice they follow. I have worked with multi card setups since the first ones on Voodoo 3d till current generations. I am not going to debate your facts as you see them because it really matter to me. I was only clarifying what I was saying as apparently people don't get it. It's fine to have a different opinion, do you not agree? For instance I don't know why it would only be a 5% downclock to pair when a reference card is 10% and in reality most non-reference boards sold are in the 15 to 25% improvement range. Sorry I didn't write a bible to write the stats of every card that can pottentially work in Crossfire in this thread. AMD already has that list and I am well aware of it. Doesn't change the fact that for most it works best when they match and even then only good results in those games optimized for it and when the drivers are working okay. None of which is today's reality for most current games.  But whatever it doesn't really matter. I was only stating what I already said that IMHO it isn't worth the trouble for most people. For some people I am sure it is.  No I don't have an DX 12 Multi-GPU experience aside from a few technology demos and benchmarks I only know of one game that supports it and I already explained this so not sure why you would need to question this, ant that game is Ashes of Singularity. I undoubtedly think that when built for the ground up DX 12 engines come on the seen with support for multi-gpu we will likely finally see the trouble trouble free solutions we all have always wanted and doing what the OP is doing will be a easy thing to accomplish. That however is still the future. I am not looking to argue and am done with this the OP and you are welcome to do whatever you want.

Also this statement "I have run an HD7970 OC 6GB in Crossfire with an R9 280X 3GB card for years. They are much more different than RX580/480. " I don't know what non reference cards you are comparing but the R9 280x reference is a straight re-badge of the HD 7970 GHz edition. But there are so many variations on these things, and doesn't really matter. I am glad if whatever you all do works for you because at the end of the day it is all anyone should want, is to enjoy playing some games, unless the fun games you are looking to play is debating in forums. Me I am just offering an opinion take it or leave it.

[colesdav]

Hi,

I do not doubt your experience at all.

When DX11 Crossfire or DX12 MultiGPU works and scales well - great. I do not think it is an absolute disaster, and in recent years my experience has been generally good.

Would I recommend someone goes out and buys two new AMD Vega 64 or 56 just to run in Crossfire or MultiGPU today? - No. We agree on that as far as I can tell.
Of course people are entitled to different opinion.
As for a 5% downclock on RX 480 8GB, lest see what exact cards they are.
AMD Crossfire Compatibility List is incomplete.
Ashes of the Singularity DX12 has shown negative MultiGPU Scaling for at least 1 year on Fiji based cards It is actually better off running it with 1 GPU active.
There are a number of games now that support DX12 Multi GPU such as Rise of the Tomb raider, Sniper Elite 4. They are pretty well known titles.

Regarding this:

Also this statement "I have run an HD7970 OC 6GB in Crossfire with an R9 280X 3GB card for years. They are much more different than RX580/480. " I don't know what non reference cards you are comparing but the R9 280x reference is a straight re-badge of the HD 7970 GHz edition.

There are HD7970 3GB GHz edition cards from Sapphire which were exactly the same GPU, Cooler etc that were simply renamed/rebadged. 

I should have mentioned the exact cards. My cards are the following:

Product Number 11197-05 Sapphire Vapor-X HD 7970 6G D5 GHz Edition.
Product Number 11221-12 Vapor-X R9 280X 3G D5

I cannot link you to the specs directly from this forum but there are many hardware differences. The R9 280X supports hardware implementation TrueAudio for example the HD7970 will not run it. 6GB versus 3GB Vram.

Bye.

[tikwid]

Is there any reason my motherboard might not be compatible with bridgeless crossfire? It's an Asus M5A97. I wouldn't think it should be an issue, but I am grasping at straws here.

[colesdav]

Hi,

Those RX580 and 480 cards should DX11 Crossfire together without any problems. Your PSU should be fine unless your CPU is something with a massive power requirement. Your motherboard states this in spec - "Quad-GPU CrossFireX Support!". Really need your System Specs but here is what I would do.

1. Set all CPU, memory  and GPU clocks to stock frequencies. I.e. turn off all overclocking. Does it work without crashing?

2. Looking at Overwatch Forums, Crossfire and SLI  have been crashing in the past, are you absolutely sure it is working now?
It could be a game specific issue. See here: Crossfire support after last update. - Overwatch Forums

3. Does Crossfire DX11 run O.K.  in any other title that supports Crossfire and runs really well for me on R9 Fury X / R9 Nano / R9 Nano system?
Examples are any of the Crysis Series, Battlefield 1, 4, ... PREY, Titanfall 1&2, Mass Effect 3, etc... You can finds out titles with Crossfire Profiles under Profile Graphics for a particular card.

You will see a list here:

There is definitely a profile for Overwatch, it should be picked up by default.

If not,  then ...

1. Make sure your Windows installation is clean, and up to date (check for updates).
2. Make sure to Turn off Windows Update.
3. Go to Control Panel -> Programs -> Uninstall your AMD Driver.
4. Power off your PC. Remove the mains supply lead to your PSU.
5. Double check your Graphics Cards are seated properly in the PCIe slot. RX580 = Primary Slot Card, RX480 = Secondary slot card.
6. Double check PCIe Power Connections to both GPU's is o.k.
7. Reconnect mains lead. Boot into BIOS. Check that both cards are seen in the PCIe slots in BIOS. Note the PCIe Speed reported.

8. Proceed and boot into Windows. Go to Control Panel -> Hardware and Sound -> Device manager -> Display Adapters. You should see two Microsoft Basic Display Adapters.

9. Download the latest version of DDU from here.Official Display Driver Uninstaller DDU Download

10. Extract DDU into a known folder.
11. Reboot into Windows in safe mode without networking.
12. Run DDU (remove but do not restart) and remove any traces on AMD drivers and Nvidia Drivers. It should tell you when it completes each cleanup. Then reboot into Windows in normal mode.
13. Download and install AMD Adrenalin 18.3.4. driver (assuming you are not running Windows 8.1? in which case I do not think there are any supported drivers for the RX 580...)
14. Reboot into Windows  after driver installation.

15. Go to Control Panel -> Hardware and Sound -> Device manager -> Display Adapters. You should see your AMD Cards identified properly as RX580 and RX480 this time.
16. Again making sure to set Set all CPU, memory  and GPU clocks to stock frequencies. Try to run Overwatch in DX 11 Crossfire.

Hope this helps.
Bye.

[tikwid]

So we made a smidgen of progress here. Out of all of those steps, the only thing I haven't already done is changing the default crossfire setting to "Use AMD pre-defined profile." The game actually boots without system-freezing, which is an improvement, but runs at about half the frame rate on "Ultra" (second highest pre-set) settings in crossfire than it does on "Epic" (highest preset) settings on a single GPU, and there is terrible texture-flickering. And worst of all, I changed the preset back to "Epic" and rebooted the game to see what would happen, and we are back to system freezing again. Feels like I'm reaching a dead end here. Thanks for the suggestion.

Specs:
AMD FX 8370 CPU
MSI RX 580 8GB GPU
XFX RX 480 8GB GPU
16 GB (2x 8GB) DDR3 1366 RAM
ASUS M5A97 Motherboard
Thermaltake 850W Smart M PSU
Samsung 120GB SSD
Additional 1TB SATA HDD (can't remember brand at the moment)
Pioneer Blu-Ray Burner Optical Drive

[colesdav]

Hi,

OK, pity it has not worked for you so far. It might just be the game. Or maybe the PCIe2.0 x4 versus PCXIe2.0x16 is causing an issue... I don't think it should though.

Can I ask if you definitely uninstalled the AMD Driver, ran DDU and reinstalled your AMD Driver after you moved the RX 480 from the primary to the secondary slot and fitted the RX580 to the primary slot?

How does the Crossfire perform if to select a different game where Crossfire is supported, like PREY, Crysis, PlanetSide 2, TitanFall 1/2, Battlefield series, etc.

What about 3D Mark Firestrike - you can download a demo version.
Does it look like Crossfire DX 11 is working o.k. in that software?

Another thing, if you have not done it for a while it might be a good idea to reflash your motherboard BIOS.
I have had problems in the past where Crossfire was broken after Motherboard BIOS corruption.

Bye.

[tikwid]

I actually just upgraded my motherboard BIOS to the latest version before installing the new card. I'll have to install another game that's supposed to be good with crossfire that would normally push my system on single GPU and get back to you

[tikwid]

Oh and yes I always use DDU when installing new drivers

[colesdav]

Hi,

That is a very good idea with the AMD installer these days.
Thanks for letting me know.

Cheers.

[colesdav]

Thanks,

That will be good debug information to have.

Bye.

[colesdav]

Hi,

You might find these interesting:

Modernizing multi-GPU gaming with XDMA

XDMA: Improving Crossfire - The AMD Radeon R9 290X Review

I looked at your motherboard manual and I see that you can run Primary at PCIe2.0 x16 (blue) or
Primary at PCIe2.0 x16 (blue) + Secondary at PCIe2.0x4 (black).

I think XDMA should work with that unless there is some additional bandwidth restriction.
I can run XDMA (bridgeless) Crossfire over a PCIe 2.0x4 connection on my motherboards for sure. I can also run Crossfire using Thunderbolt 2.
If you really get stuck I can set up one of my motherboard to see how far down in PCIe bandwidth I can go before Crossfire will not work.

I do know that Crossfire does not work for me so far on HD7970 OC 6GB with R9280x 3GB over PCIe 2.0x1 -> USB 3.0 -> PCIe using a Crossfire Bridge. (They do not have XDMA (bridgeless) Crossfire support though).

Bye. 

[elstaci]

for Crossfire to work, the PCIe slots must run at x8 speeds. PCIe2.0x4 won't activate Crossfire.

How do I setup AMD CrossFire™ on my system?

​If you would like to setup AMD CrossFire between two or more discrete graphics cards (PCIe socket cards) correctly, please read the following steps:

1. Please make sure that the power supply unit meets the recommended requirements of the complete AMD CrossFire setup.  There are free 3^rd party tools available online that can determine the power requirements of your system.

2. Check with your motherboard manufacturer that your motherboard is AMD CrossFire compatible with the required number of PCIe x16 slots available (running at a minimum of PCIe x8 speed).

3. Check the AMD CrossFire Compatibility Charts to verify that the cards you are using are recommended for AMD CrossFire.

4. Please make sure that you are properly grounded and the system is powered off before installing the graphics cards.

5. Connect the preferred card into the primary PCIe slot on the motherboard (check motherboard manual to determine the primary PCIe slot).

6. Connect additional cards to the secondary PCIe slots on the motherboard.  Note: AMD CrossFire only supports up to 4 GPUs.

7. If any AMD CrossFire bridge cables were included with the graphics cards, please connect them now.

8. After starting up the system ensure that you install the latest compatible driver for the graphics cards.

9. Go to the AMD CrossFire option in the AMD Catalyst™ Control Center and make sure that the check box for "Enable AMD CrossFire" is checked.

Note: For AMD Dual Graphics setup with an APU and a single discrete graphics card connected to the PCIe slot please see the AMD Dual Graphics FAQ.

[tikwid]

According to Asus, my motherboard is supposed to be crossfire compatible and i have seen others have success with the same exact motherboard. I may end up switching out the motherboard anyway, but I'd like to avoid that if I can.

[elstaci]

Your problem doesn't sound like a bad motherboard. It is either the game is not compatible with Crossfire or a GPU configuration problem or even a BIOS configuration problem.

I just mentioned the previous post because you need two PCIe16 2.0 x 8 for Crossfire to work. In your case, Crossfire is working. So it isn't a problem with your motherboard.

[colesdav]

Hi,

Thanks.

I know I can definitely run Crossfire or Trifire with PCIe 3.0x8, PCIe30x8 and PCIe 2.0x4.
The AMD Crossfire Compatibility charts are inaccurate and very out of date.
It does not show all of the information including inter-generation cards that work together either.
I am about to find out what happens if I try Overwatch with two cards, 1 at PCIe2.0 x8and the other running at PCIe 2.0x4.

Will let you know soon .

Bye.

[elstaci]

PCIe3.0x4 is the same as PCIe2.0x8

[colesdav]

Hi,

Sure, but my motherboard supports PCIe2.0x4 at maximum bandwidth in the third slot and the card does show up as running in Crossfiire.

Thanks.

[colesdav]

More info here:
CrossFire RX 580 + RX 480 Benchmark vs. Single GPU - YouTube
Bye.

[colesdav]

Hi,

There appear to be plenty of examples of people running RX580, RX480, R9 Fury's in Crossfire with good results in Overwatch on Youtube as recent as a few months ago.
See:

AMD Ryzen 7 1700 + 2x Rx 480 (Crossfire) Twitch Live Stream Test Overwatch - YouTube​

Ryzen RX 580 Crossfire Overwatch 1440p - YouTube

crossfire sapphire rx 580 special edition in Overwatch - YouTube

Ryzen RX 580 Crossfire Overwatch 1440p (frame pacing on) - YouTube
# 458 [game] - Overwatch - Performance | R9 Fury | Crossfire - YouTube

They look good to me.

I do not think you should have to flash your RX480 BIOS with an RX580 BIOS to get those cards to work together.

Bye.

[colesdav]

High

What does the CPU utilization get to when running 1 RX 580/480 get to in Overwatch with Crossfire off?
Looking at Intel Core i7 4770K vs AMD FX 8370 it might be the case that your CPU is not powerful enough.
I have found that running Crossfire incurs additional CPU load.

Bye.

[tikwid]

When I play overwatch in single GPU my CPU usage is usually around 60%, it can get up to 100% in rare situations where theres lots of particles and effects flying around on the screen but in most situations it hovers around that 60% point more or less, so I wouldn't think just booting the game should cause a hard lockup for that reason, and there are other people demonstrating overwatch with dual 480s and the same CPU as me. My first thought was maybe my PSU is faulty or my motherboard is finicky

[colesdav]

Hi,

OK, in that case it sounds like you might be in difficulty getting best scaling with two 480's  or 580/480 in Crossfire, but it should stil work.
I agree it should not cause a hard lock up but often I see that CPU Utilization will get to 100% when loading some games.

Can I ask if you have other GPU Overclocking tools such as Asus GPU Tweak II, MSI Afterburner etc installed?
If you do, it might be a good idea to uninstall them.

I agree it could be your PSU or your motherboard.

I do remember that when the RX480's were launched at first that the PCIe connector was drawing more power than expected and it was causing some issues with older/lower cost motherboards locking up. I had thought that issue had been fixed in Card BIOS or Drivers. I did read from technical articles about it that people who did overclock their GPU's (not just RX480's) would have likely been  be pulling "more than Spec Power" from their motherboard PCIe Slots in the past.

However, it may be if you are overclocking your RX 480 to match the speed of the RX 580 something might be going on like that.

Bye.

[tikwid]

Thanks for the info. I'm actually not overclocking anything unless you count that i think my 480 is supposed to be "pre-overclocked" by the manufacturer. I've honestly never been comfortable messing with any of that and don't have afterburner or anything installed

[colesdav]

Hi,

Thanks for the info.
Please enable Wattman and increase the Power Limit, temp target and fan target to maximum on both cards.
Do not touch the GPU Clock or RAM frequencies.
You are not overclocking the cards by doing this, you are just setting them to run at maximum performance at rated clock speeds.

I just got access to Overwatch so I can look into this issue for you using my R9 FuryX/Nano/Nano cards (3 cards on 1 PC).
I will see how it runs in Crossfire and Trifire with i7-4790K with 32GB RAM.
If that works out O.K. I will disable one of the cards and see what happens if I change the PCIe Bus speeds to match yours.

Bye.

[tikwid]

Thanks for the suggestion. I was thinking about trying that but was afraid increasing the power limit might damage something. I think I'll go ahead and give it a shot when I get home.

[colesdav]

OK, thanks.

Here is a video showing Overwatch running on my System with Crossfire Enabled for you:
Testing Crossfire DX11 in Overwatch for AMD Community Forum. - YouTube

Please watch the video.
I used the Radeon Overlay to monitor the GPU Utilization on both cards and CPU Utilization is also shown.
I will look at running with Crossfire disabled next.

Bye.

[tikwid]

Looks beautiful so far, although the real test would be to see some players shooting each other. Is that Epic preset?

A decent way to test the FPS in this game if you don't want to mess with other players is to set up a custom match with all bots and view as a spectator. Some good maps to test on are control maps like Nepal and Oasis, as these encourage a lot of close quarters fights with all 12 players blasting particles and effects on the screen.

[colesdav]

Hi,

The cards are running at PCIe 3.0x8, PCIe3.0x8.

Yes it is the Epic Preset at 1080p, I gave some information in the video description.
If I turn Crossfire off in global settings for the Primary card I am getting at best about 80 - 100 FPS, with the player level to the horizontal.
With  Crossfire on in Global settings I am getting about 160-170 FPS in similar scenes.
So taking those rough measurements the scaling is looking reasonable at around 1.7.
I have not tried setting up a custom match yet, I had not seen your post.
In any case.

I will get on with looking at setting up PCIe 2.0x16, and PCIe2.0x4 Crossfire. I have to power down to remove my second R9 Nano and fit it in the PCIe 2.0x4 slot.

I did find one way to lock up my PC with overwatch.

1. Power up the PC with Crossfire disabled.

2. Launch Overwatch and start the game in Training AI mode
3. TAB out to Radeon Settings.
4. Turn Crossfire off in Global Settings.

Guaranteed hang for me.

Bye.

[tikwid]

So I just got home and tried your suggestion of increasing the power limit to +50% and turning the fans on max. Unfortunately the results are worse as the game immediately crashes even when the in-game graphical settings are default, whereas before I at-least go the game to run at horrible speed. This makes me wonder if it really is an issue of the cards drawing too much power or the PSU not being compatible.

[colesdav]

Hi,

Here is a Toms Hardware article about the RX480 and the fix: AMD To Issue Software Fix To Address RX 480 Power Consumption Problems
It should have been fixed years ago though. Ithink your PSU has enough Power Rating. However it might have a problem.
It might be an idea to see if a friend will let you swap PSUs to test?
Maybe your motherboard has problems and you might want to swap it out.

Bye.