ประสิทธิภาพที่ต่ำกว่าของ Silver?

I think it's a bit of both. Silver definitely has higher beta, so it can underperform in risk-off periods. But I wouldn't discount industrial demand concerns completely; that's a significant part of silver's use case.

Could also be the short-term speculative interest in gold just outweighs silver right now. I wouldn't read too much into it over just a few weeks; the long-term trend for precious metals is still broadly positive.