Appears I can't use all 4 GPU's for RT GPU (only) rendering

[JezUK]

I'm trying to figure out why my RT renders have been erroring (RT Activeshade GPU only).

After some detective work (basically eliminating all warning message), I finally got my RT renders to work, and then went a step further, increasing the number of GPU devices being utilised from 3 to all 4 (i.e. also including the display GPU).

My render errored. Restarted Max, render errored again. Went back down to 3 GPU's (not using the Display GPU) and my RT renders work again.

Seems I can't use all of my 4 GPU devices for rendering....

(Whilst I'm rendering, I have no other programs open, just 3DS Max).

[matanov]

Please send me the scene for investigation. Also I've noticed that you are trying some of the iToo tutorials, keep in mind that some of them are fairly old and are using legacy materials and textures. Use the V-Ray scene converter on them (right click menu) for more predictable results

[JezUK]

Hi Peter,

Thanks for your advice given to my 2 messages a short while ago.

As this is a client project, and the deadline is very near, if I send it to you now, can you take a look at it today please ?

Many thanks.

[matanov]

I'll try

[JezUK]

Thanks Peter I've sent it to support@chaosgroup.com as well as your personal email address.

Many thanks.

[JezUK]

Peter,

I've solved this particular issue - it was my pagefile.sys - it wasn't big enough.

Once I increased its size, all 4 gpus aided in the rendering of my scene.

It's been a hectic 24 hours for me since getting my 2 extra gpus, but the investment I am even more sure now is going to be worth it - I am getting quality 2K renders via RT Production in around 5 minutes (where normally I would wait around 45 for my single 5960x cpu ).

Please , if you could however keep investigating the scene file I sent you today and pass on any obvious nuggets of information that'd be worth me knowing, I'd be really grateful.

Many, many thanks.

[matanov]

This is pretty strange because I've tried your scene and it took 31GB of RAM and from your signature I see you have 64, so I don't see any need of using the pagefile. All 4 1080ti ran successfully on my machine on the first try with 3.60.01 and latest RC and FP.

[JezUK]

Hi Peter,

Before, I had a very small pagefil.sys. At the time (2 years ago) I didn't need one and also my OS disk isn't that big, so I needed the space for software so a small pagefile.sys wasn't a problem back then.

Only now that I have invested in GPU rendering I started to get this message, so it took me a while to work out what it was trying to tell me, so I deleted a lot of programs and to create the pagefile.sys I now have (variable from 5 to 50Gb).

Once done, I noticed the Pagefile.sys got to around 18Gb with this scene, so for sure, before when I that pagefile I had before of just 1gb (fixed) was clearly not enough.

So, as far as I can see I've fixed it and RT is working beautifully for me right now - renders are very fast. Simply amazing and a whole new world

Thank you so much for taking the time to investigate - I really appreciate your efforts and all you guys at Chaos.