You can't use Pascal GPUs (TITAN X (Pascal), GTX 1080, GTX 1070, GTX 1060, GTX 1050, GTX 1050Ti) mixed with older GPUs in the same system, as the 9.14 app does not support older cards, and the 8.48 app does not support Pascal GPUs, and the BOINC manager does not know or take care about this, and it will make every workunit on the older card fail, thus your host will use up its daily quota in a very short time.
You have 2 options:
1. remove the older card
2. disable the older card in BOINC manager for GPUGrid (in cc_config.xml)
To do it, you have to know the number of the GPU to be disabled according to BOINC manager. You can find this information in the first lines of the event log of your BOINC manager (at its startup). For example:

2017.01.29. 18:06:49 |  | CUDA: NVIDIA GPU 1: GeForce GTX 750 Ti (driver version 372.90, ...

Copy the following to your clipboard:

notepad c:\ProgramData\BOINC\cc_config.xml

Press Windows key + R, then paste and press enter.
If you see an empty file, copy and paste the following text:

<cc_config>
  <options>
    <exclude_gpu>
      <url>www.gpugrid.net</url>
      <device_num>1</device_num>
      <type>NVIDIA</type>
    </exclude_gpu>
  </options>
</cc_config>

The value in the <device_num> section should be adapted to the given system.
If your cc_config.xml already has an <options> section then you should insert the section between the <exclude_gpu> and the </exclude_gpu> tags (including both) right after the <options> tag.
Click file -> save and click [save].
If your BOINC manager is running, you should click Options -> read config files.
Perhaps you should restart BOINC manager (stop the scientific applications upon exiting).
You can have as many <exclude_gpu> sections in your cc_config.xml as many GPUs you have to disable.
This way other projects can use your older card(s) until GPUGrid will have an app which can use Pascal and older GPUs. (Then you have to remove this <exclude_gpu> sections from your cc_config.xml. You should also remove the <exclude_gpu> section(s) if you upgrade your older card to a Pascal.)

Ok, thanks ZOltan !

I hope this gets resolved soon as I want to get on cracking GPUGrid at double speed ;-)

GPUGrid should release a single app, that works for all the GPUs.

GPUGrid should release a single app, that works for all the GPUs.

I've been wondering about this for a long time. Why for the first time did they bring out an app that wasn't backwards compatible?

GPUGrid should release a single app, that works for all the GPUs.

I've been wondering about this for a long time. Why for the first time did they bring out an app that wasn't backwards compatible?

Originally we were waiting for the release of the CUDA 8.5, do you remember?
Then, out of the blue a CUDA8.0 app came, to meet the demand for a Pascal app.
Of course it would be better to have a single app for all cards, beside that I'd like to keep the present CUDA6.5 app for my (and for everyone's) Windows XP hosts, as I don't want to crunch on a WDDM OS.
But this discussion belongs to its own thread.

If I buy a Pascal GPU, I will want to mix with Maxwell GPUs. My PC's usually have 3 GPUs, across 2 generations, in them.

Right now, my 2 PCs are:
- RacerX: GTX 970, GTX 660 Ti, GTX 660 Ti
- Speed Racer: GTX 980 Ti, GTX 980 Ti

I plan on getting a GTX 1080 Ti (if/when it's released).
GPUGrid should support me putting it somewhere, without losing functionality of all these other GPUs.

I have asked Matt for info on this

Thanks GDF and Matt.
We're hoping you can make this work!!

http://gpugrid.net/results.php?hostid=380872

This host runs a GTX1060 and a GT730, both crunching GPUGRID, the later only short runs...

Somehow it works for me.

It seems that the CUDA 8.0 client v9.14 for Linux supports older generation cards as well.
Do you manually assign short task to the GT730? (as the BOINC manager can't do it on its own, as far as I know)

I exclude acemdlong for the GT730 in cc_config.xml...

    <exclude_gpu>
           <url>http://www.gpugrid.net/</url>
           <device_num>1</device_num>
   	   <app>acemdlong</app>
    </exclude_gpu>

In case anyone is wondering about mixing <use_all_gpus> and <exclude_gpu>, the following works just fine.

It runs all GPUs on projects, except GPUGRID, in which case it excludes the 2nd GPU eg #1.

<cc_config>
    <options>
        <use_all_gpus>1</use_all_gpus>
	<exclude_gpu>
      		<url>www.gpugrid.net</url>
      		<device_num>1</device_num>
      		<type>NVIDIA</type>
    	</exclude_gpu>
    </options>
</cc_config>

I exclude acemdlong for the GT730 in cc_config.xml...

    <exclude_gpu>
           <url>http://www.gpugrid.net/</url>
           <device_num>1</device_num>
   	   <app>acemdlong</app>
    </exclude_gpu>

I don't know why I haven't thought of this, but thanks for pointing out that a specified app could be excluded from a given GPU.

Keep in mind that, when work fetch asks the server for work, it doesn't send any of your exclusion info. Thus, it's entirely possible that you might not get enough work of the right types, to keep your GPUs busy.