I get a Sync error when rendering with my 1050ti and my 980ti. but if i render with just the 980ti it works fine with no error. is this a bug with the 1050ti or the pascal gpus or is my version broken cause ive reinstalled already and used the beta for the next release and it still happens.
The smallest ram pool available will limit how complex the scene can be.
Gliderman hints at this in his comment.
For your case:
A 980ti has 6GB of Ram while a 1050ti is listed as 4GB.
If you want to use multiple GPU rendering you will have to ensure your scene uses less than the smallest GPU ram pool available.
In your case this is 4GB.
The official docs for blender state that that multiple GPUs do not share memory here
Would multiple GPUs increase available memory? No, each GPU can only access its own memory.
You are limited by the available ram of the 1050ti if you wish to do GPU compute
CPU Compute - This is usually slower by quite a bit but you usually have a larger ram pool available. My PC has 16gb of system ram and only 4gb of video memory for example, but even an I7 is still pretty slow compared to a GPU
Reduce Texture Memory - If you are using cycles rendering engine, you can try to generate some procedural textures for things that may not need as much detail.
Render Layers - Render Layers can allow you to mantain scene complexity but it can be tricky to balance how light interacts. If you use render layers you will need to use the compositor to restore the scene to the full image you had in mind.
- Buy a video card pair - This one is really straight forward, it just requires a significant sum of money to accomplish usually. I do not recommend this unless you already had a need to upgrade for other reasons.