got a reference?

That is simply not true.

Please be more specific. What is not true? That it is slower or that this is not the end of the world?

Wow, people are butthurt. It's a wildly known fact in the industry. A simple google search for benchmarks or a PDF like this would have satisfied them. But they didn't want the truth they wanted to be butthurt.

https://arxiv.org/ftp/arxiv/papers/1005/1005.2581.pdf

In basically every chart and graph, OpenCL is slower.

OpenCL has a higher level of abstraction, so it's got a higher penalty for it. But, you get cross-platform support. nVidia doesn't optimize for OpenCL either because they don't want you to use it over their own competing framework.

But 'dats cool, keep downvoting, guys. Sources aren't real if you can downvote 'em enough. God, I love Hacker News.

Would you kindly raise the level of discourse here? You have useful information, so thanks for sharing it. But please leave the swipes and complaints about downvotes and HN members out of it. It worsens discussion and is against the guidelines. You’ll likely receive downvoted for that, more than anything else.

This reddit-style, highly emotional commenting is not terribly welcome on HN.