Dual-SIM - Does using 2 SIM cards affect the perceived network performance?

jassingh,

Any slowing of the phone should be perceived, and probably minimal in a dual SIM phone. From my understanding the dual SIM phone will use slightly more battery as it is monitoring two SIMs for incoming calls and texts, and also uses algorithms to choose which SIM to use for making calls and texts (although this will be often have user input to decide or ask for your input).

Certainly my experience of a dual physical SIM phone quite a few years ago, I could decide to use both SIMs, or just one, depending on respective signal strengths at the time, occasionally checking the signal of each SIM.  This was in the days of being an advenced skills first aider for SJA in Surrey, and often encountering variable signal strengths when on duty.

I agree with Strandloper any reduction in speed / performance should be minimal.

I have used various android dual sim phones over the years, and now have an iPhone 13 mini. 

Naturally, the physical sim slot is used by my Smarty physical sim and the eSIM slot is used by a variety of eSIM’s, of which the iPhone can store 8 eSIM profiles.

Personally, I think dual SIM phones are very useful, especially when travelling.

I'm with Strandloper and JJP2 on this - you'd expect any speed / performance hit to be minimal. 

I'd guess without some benchmarking, to test different scenarios in a dual-SIM system handset, one's own experience / observations could be somewhat subjective. 

I reckon dual-SIM devices are great for roaming, and have helped me avoid large roaming charges when I've been somewhere that prohibits use of my SMARTY plan allowances.