<p><code>lspci</code> lists PCI devices. <code>./poclbm.py</code> lists OpenCL devices. If the former finds the device but the latter does not, your second GPU must not be registering as an OpenCL device.</p>

<p>Ubuntu 11.10 has a notorious reputation for multiple-GPU bugs. (See <a href="https://bitcointalk.org/index.php?topic=53199.msg667050#msg667050" rel="nofollow">here</a> and <a href="https://bitcointalk.org/index.php?topic=50388.msg601325#msg601325" rel="nofollow">here</a>.) I personally have had issues with 11.10 mining that were resolved simply by switching to another release. I would suggest you instead use Ubuntu 11.04 (Natty Narwhal); it is generally regarded to be the most reliable Ubuntu version for mining.</p>

<p>If that is not an option, or installing 11.04 doesn't fix the problem, try the following steps:</p>

<ol>
<li>Uninstall whatever version of Catalyst/SDK you have (make sure to remove all configuration files) and install
Catalyst 11.6 and SDK 2.4.  </li>
<li>Run <code>aticonfig -f --initial --adapter=all</code> again. Make sure it runs without errors.</li>
<li>Run <code>aticonfig --list-adapters</code>. You should see two. </li>
</ol>

<p>Those steps should fix any configuration issues. If your problem persists, it's either a hardware issue (or an Ubuntu 11.10 issue).</p>

CC BY-SA 3.0
2012-03-16T02:01:29.993Z
2012-03-16T02:01:29.993Z
BinaryMage
<p>Try not booting into graphical mode at all, just command line. Leaving compiz/gnome/gdm/drivers off should alleviate most confusion, as the cards should both be in default modes (and one in VESA/VGA) and for the most part will be untouched by system specifics (more like normal PCI devices)</p>

CC BY-SA 3.0
2012-04-05T01:34:40.740Z
Unfortunately, that won't work; ATI OpenCL under Linux requires an X server running.
BinaryMage
CC BY-SA 3.0
2012-04-04T22:16:08.563Z
2012-04-04T22:16:08.563Z
Colin Godsey
<p>I have an Ubuntu set up (11.10) and 2 ATI Radeon HD 6870 cards. It detects one, but not the other for some reason when I try to run <code>poclbm</code>. </p>

<p>When I run <code>lspci</code>, it finds both cards.</p>

<p>Any help?</p>

CC BY-SA 3.0
2012-03-16T06:09:51.440Z
Try the command  display=:0  .
Meni Rosenfeld
CC BY-SA 3.0
2012-04-04T22:43:15.170Z
Maybe this is not going to help you, but... Ubuntu is a  distribution strongly oriented towards casual users, are you sure it's a wise choice to use it for mining? Couldn't you just use, for example, debian?
o0'.
<ubuntu><poclbm><gpu>
How can I enable more GPUs in Ubuntu for poclbm?
Shamoon
# How can I enable more GPUs in Ubuntu for poclbm?

(Asked by: username_0 on 2012-03-09)

I have an Ubuntu set up (11.10) and 2 ATI Radeon HD 6870 cards. It detects one, but not the other for some reason when I try to run `poclbm`.

When I run `lspci`, it finds both cards.

Any help?

**Tags:** ubuntu, poclbm, gpu

> **Comments:**
> **username_1**: Try the command  display=:0  .  
> **username_2**: Maybe this is not going to help you, but... Ubuntu is a  distribution strongly oriented towards casual users, are you sure it's a wise choice to use it for mining? Couldn't you just use, for example, debian?  

---

## 2 answers

### Answer by username_3 on 2012-03-16. Score: 2 | Accepted answer

`lspci` lists PCI devices. `./poclbm.py` lists OpenCL devices. If the former finds the device but the latter does not, your second GPU must not be registering as an OpenCL device.

Ubuntu 11.10 has a notorious reputation for multiple-GPU bugs. (See [here](https://bitcointalk.org/index.php?topic=53199.msg667050#msg667050) and [here](https://bitcointalk.org/index.php?topic=50388.msg601325#msg601325).) I personally have had issues with 11.10 mining that were resolved simply by switching to another release. I would suggest you instead use Ubuntu 11.04 (Natty Narwhal); it is generally regarded to be the most reliable Ubuntu version for mining.

If that is not an option, or installing 11.04 doesn't fix the problem, try the following steps:

1. Uninstall whatever version of Catalyst/SDK you have (make sure to remove all configuration files) and install
   Catalyst 11.6 and SDK 2.4.
2. Run `aticonfig -f --initial --adapter=all` again. Make sure it runs without errors.
3. Run `aticonfig --list-adapters`. You should see two.

Those steps should fix any configuration issues. If your problem persists, it's either a hardware issue (or an Ubuntu 11.10 issue).


---

### Answer by username_4 on 2012-04-04. Score: -2

Try not booting into graphical mode at all, just command line. Leaving compiz/gnome/gdm/drivers off should alleviate most confusion, as the cards should both be in default modes (and one in VESA/VGA) and for the most part will be untouched by system specifics (more like normal PCI devices)

> **Comments:**
> **username_3**: Unfortunately, that won't work; ATI OpenCL under Linux requires an X server running.  

---

