Unofficial AMD Bugzilla – Bug 1193
Can not enable CrossFire mode. AMD tech.support asked me to fill a bug here.
Last modified: 2015-09-04 16:05:07 CDT
Description of problem:
I have two graphics cards of the same model. I want to use them in CF (CrossFire) mode on Ubuntu linux. I get a following message in a console (see below in "Actual result").
On Windows CF is supported and works as should for the same hardware.
Graphics cards' GPU: AMD Radeon HD 7790 (Gigabyte GV-R779OC-2GD)
Mainboard: ASUS P5KC.
I asked AMD tech. support the following questions (I need only an info from them):
Q1. Do exist any hardware configuration at all, wich can support CF with OS (K)Ubuntu 14.04 (or higher)?
Q2. If if is possible, describe all the criteria to choose such hardware, please. Especially, for 2 * Radeon HD 7790.
Q3. If CF mode is impossible for Radeon HD 7790 on OS (K)Ubuntu at all, tell do exist any graphics cards that can work in CF mode on this OS, please?
Q4. What does it mean the following message of aticonfig ("CrossFire can work with P2P mapping through GART")? I. e., I mean when and/or on which hardware "CrossFire can work with P2P mapping through GART"? I've got such message on KUbuntu 14.04. If it possible at all I would like to try to use PC components (mainboard, etc) specially to use CF on this OS.
Q5. If CF mode can not be enabled for all existing hardware configurations for the specified OS, confirm this fact, please.
If any hardware configurations exist, where Ubuntu can support CF mode, I ask you give me sufficient criteria, how I can find such hardware. May be, some chipsets and CPUs, based on AMD architecture (not Intel) can support this feature.
Is this problem specifical only for Radeon HD 7790 or is common for all the AMD graphics cards (CF is impossible for Ubuntu)?
AMD tech.support did not answer most of my questions, and said only that:
A1. There is no crossfire support for AMD Radeon HD7790 with KUbuntu 14.04 O.S.
A2. Then (later) they asked me to fill in a bug report here ("Please provide your feedback through AMD Bugzilla file bug report issue. Please refer below link http://ati.cchtml.com/").
Steps to reproduce:
1. Install two graphics cards and connect them by a CF-connector. Install official proprietary driver via GUI installer.
2. Enable CF mode via Catalyst software. Restart a PC.
3. Enter in a console:
CrossFire actually is not supported. The message in a console is:
CrossFire is disabled on current device
CrossFire can work with P2P mapping through GART
Dongle Capabilities: support PASSTHROUGH |INTERLINK_SW_AFR | INTERLINK_AUTO_AFR | INTERLINK_BLACKING | INTERLINK_SUPERAA
1. CF mode is enabled and actually works on Ubuntu.
2. AMD experts explain how to choose hardware components (mainboard, graphics cards etc), which can support CF mode for Ubuntu (if it is possible at all).
3. If CF mode can not be enabled for all existing hardware configurations for the specified OS, AMD experts confirm this fact.