Dual Xeons vs Multiple GPUs running costs

[cadman5]

Anyone knows what is the running cost difference (percentage wise) for a system with a dual E5 2690 and say 1 gtx 1080 ti card vs a system with a good performance i7(not the latest by any means) and 3 gtx 1080 ti cards?...
Not asking for exact numbers, just a percentage estimate ...anyone have any idea?.. Cheers

[delineator]

I don't understand the question, what are you exactly looking for? Are you wondering what the wattage would be? Just plug your part numbers in and look for TDP/wattage specs. Impossible to know which i7 you mean though. Also depends on what other "stuff" you have in your xeon system vs your i7 system (ram, hdd's, etc etc). Also also remember that tdp isn't really power draw, but whatever.

ignoring everything else, 2690's advertised tdp is 135w, 1080ti's are around 250w (I think), and a 6700k has like a 90w tdp.

Finally, keep in mind that gpu compute power =/= cpu compute power. Additionally, in case your looking to swap xeon guts into a pre-existing core i7 based system, remember that psu wattage is only 1 factor, your psu probably doesn't have the required connectors nor does the case probably support eatx motherboards

[cadman5]

Thanks delineator. I was looking for a running cost comparison of a dual Xeon E5 2690 vs GPU rendering configuration. I guess the Xeon configuration maybe more expensive at first, but then the running costs of GPU will make it much more expensive in time?. (all providing both system always render comparable hi-res clean images)

[particlerealities]

I'm certainly no expert, but you should factor in upgrade costs as well. I'd think it's much cheaper to upgrade graphics cards than to upgrade CPUs, which may require an entire system rebuild to support newer chipsets.

[delineator]

(all providing both system always render comparable hi-res clean images

right, but that's the issue: you can't really compare without very specific information. IE you can take a single scene and test it out on gpu vs cpu, but it all depends on what your working on, how you render, how you set up your files, what plugins you use etc etc before you even KNOW if you can take advantage of gpu rendering and also if it will scale to whatever your doing. If we had more information, we could advise, but before dropping any money, I would advise you to do some a/b test and really think about how your using vray and how gpu will work into that whole workflow.