290x crossfire problem

Toggle sidebar Toggle sidebar
M

MatMatthewMat

Reputable
Mar 16, 2014
30
0
4,530
Hey. Here is the problem. I´ve got two 290x of different brands. One is made by Asus and the second by Sapphire. They are both reference cards with one cooler, looking all the same. Originally I was using the Asus 290x with 700 watt psu, playing on triple monitor (bf3) on medium details. I had a chance to buy a second 290x for very good price. So i bought it and ordered new 1000 watt psu (92% efficiency). The Sapphire card was running same as the Asus card. I didn´t even need to reinstall the drivers.

Today the new psu came. I´ve installed the hardware properly, uninstalled old drivers, installed the newest catalyst 14.12. The computer recognizes second gpu, they work together in crossfire, but the result is worse than gaming with a single gpu. Fps are low.. When I unclick crossifre in CCC, everything works fine. I´ve tried clean uninstalling twice, I´ve changed the order of cards... Nothing.

When I turn on Gpu tweak, I am able to controll both of them properly (fan speed), the clock speed runs perfect on both (1000,5000)... But the bios is different on each card (up to date)....

I don´t know what to do, I want to kill myself for making this "good bargain". Can you help me?
 
Sort by date Sort by votes
The mismatched BIOS is almost certainly your issue. Asus fiddles with the BIOS on their cards, esp. the factory overclocked versions, and they do not crossfire with other models. I had a build with an Asus 7850 DCII and an Asus 7850 DCII T.O.P. (factory overclocked version). Crossfire didn't work until I flashed the T.O.P. BIOS to the regular DC II.
 
Upvote 0 Downvote
Have you also downloaded and installed the latest Catalyst Application Profiles (CAP)?

Also, what is your motherboard? Do you have a board that has at least a PCI-e x16/x8 or x8/x8 slot configuration? If you've got a board that does x16/x4 you could have a card which is being starved and causing all kinds of imbalance issues.
 
Upvote 0 Downvote
This is my setup:
AMD FX-8350 Black edition, 4 GHz
Gigabyte 970A-UD3
Kingston HyperX Blu, 1600Mhz, 3x4GB, DDR3 ram, XMP
Kingston SSDNow V300, 120GB
Seagate Barracuda 7200.12, 1TB
CoolerMaster HAF 912 Plus
Noctua NH-U9B SE2
Lepa G1000M
Asus 290x (http://www.asus.com/sk/Graphics_Cards/R9290X4GD5/)
Sapphire 290x (http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1227&pid=2085&psn=&lid=1&leg=0)
 
Upvote 0 Downvote


How to match the BIOS on the second card?
 
Upvote 0 Downvote
That's a gamble. You have to flash the BIOS from one card to the other. This worked with the two 7850's because they were physically the same PCB. I would only recommend doing it in your case if one of the cards has a dual BIOS (i.e. you can restore if the flash doesn't work).
 
Upvote 0 Downvote
Also, when installing cards in crossfire you have to go through a more complicated process:

insert 1st card in first slot.
install drivers for first card card.
shut down, remove 1st card.
insert 2nd card in second slot.
install drivers for second card.
shut down, reinsert first card in first slot.
install crossfire bridge.
 
Upvote 0 Downvote


So it´s not a good idea? Shoul I sell the card? Isn´t there any other solution?
 
Upvote 0 Downvote


There is no crossfire bridge on 290x. Am I wrong?
I will do every one step as you wrote. When I´m done, I´ll let you know.
 
Upvote 0 Downvote


One more question... Which drivers should I install? CCC 14.12 on each card?
 
Upvote 0 Downvote


Just as I thought. Take a look at your motherboard setup. That motherboard has 3x PCI-e x 1 slots, one PCIe x16 slot, and one PCI-e x4 wired in a PCI-e x16 physical slot. So, part of the reason you may be having bad Crossfire experience is that you have a big, high powered card on a PCI-e x4 lane.

Here's a very interesting article:

http://www.tomshardware.com/reviews/pci-express-scaling-analysis,1572-2.html

Note that this was written in 2007, and cards have only gotten significantly more powerful since then. Take a look at some of the older cards which bottleneck badly on the x4 lanes. Most cards do ok on x8, but as noted, your slot setup is an x16/x4 which explains why enabling crossfire chokes on you. Disable it and it runs on the x16 card, enable it and one card is capable of only x4 bandwidth while the other is at x16.

See why it doesn't work right?
 
Upvote 0 Downvote
Good catch. Actually, it's worse than that. The chipset only has 16 lanes to divide, and the way PCI-e works, the two cards will run at x8 and x4 when installed together.

This wouldn't be a problem on pci-e 3.0, as 4 lanes of 3.0 is enough for the 290x, but the AM3+ platform only supports PCI-e 2.0, and the bandwidth issue is exacerbated by the fact that 290's don't use a crossfire bridge.
 
Upvote 0 Downvote


What is the solution?
 
Upvote 0 Downvote


So are you telling me that I am literally because no crossfire bridge and my am3+ motherboard?
 
Upvote 0 Downvote


Yes, easily. It lists full x16/x16 capability, which means your mobo won't be restricting the cards at all. Just make sure you put them in the recommended slots as it has two full sized (but wired electrically) x4 slots, and two full sized wired x16 slots. They're labelled pretty well.

Just make sure you get a 990fx series chipset to make sure you get the full complement of the PCI-e lanes. The 990x and 970 series have fewer lanes which limits your crossfire options.

 
Upvote 0 Downvote
The MOBO came today, my friend helped me. I´ve reinstalled the drivers... And guess what? 😀

IT´S RUNNING UNBELIEVABLE 😀

I am able to play Battlefield 3 on three FHD monitor at ultra settings while everything is smooth and nice.

Thanks a lot for your help guys. You were very helpfull :)
 
Upvote 0 Downvote


Glad we could help! Happy BF3'ing. 😀

 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom