Xiaomi Cross-Device Sync: My View Changed After Two Days

Last Wednesday evening, I recorded an interview on my phone while on high-speed rail. After getting off, I wanted Super Xiao Ai (Xiaomi's voice assistant) to list the questionable points in the transcription. When I returned to my computer and asked again, it gave a new answer, as if the keywords confirmed on the phone never happened. At that moment, I was quite annoyed. Investigative reporting fears broken context the most: remember a sentence on the phone, forget it on the computer.

So when I saw IT Home report that HyperOS 4's Super Xiao Ai supports conversation sync between phone and PC, my first reaction wasn't "finally," but "what exactly is being synced?" According to official statements, this cross-device collaboration mainly covers three things: phone and PC conversation sync, allowing you to continue chatting after switching devices; finding files via a voice command on your phone when the PC isn't nearby; continuing tasks started on your phone on another device.

My Xiaomi phone and PC upgraded to HyperOS 4 over these two days, same account, Device Center enabled. Let me explain two terms: Super Xiao Ai is the voice assistant and task entry point in the Xiaomi system, not just dictation—it can remind, find files, and execute some in-app operations; cross-device collaboration simply means letting the phone and PC share current sessions, task statuses, and device permissions.

The preparation phase was more verbose than I thought. After upgrading the phone, a pile of permission pop-ups appeared, and I missed a toggle allowing session sync between devices. The official Cross-Device Linking page repeatedly reminded that supported models, versions, and app scopes depend on the details page. I watched several experience videos and verified from multiple sources; the functional descriptions were consistent, but the boundaries were vague.

The device list is illustrative of controllable devices; please refer to actual usage.

In my tests, the surprise came during the second conversation. On my phone, I said: "Organize the three questionable points from that interview earlier into follow-up questions." Opening Super Xiao Ai on the PC, the session list showed a source from the phone. I continued asking: "Change the third point into an email draft." It didn't ask me to re-paste the recording or explain what the third point was. For writers, this feeling of not having to repeat oneself is indeed convenient.

However, it's not foolproof as advertised where switching devices lets you chat seamlessly. When finding files, I said on my phone "find last week's contract PDF," with the PC on, and results appeared; after the PC went to sleep, the same command failed. File search also depends on naming; I have folders with dozens of "New Document" files, and Xiao Ai hits standard PDFs but struggles with messy names. Task continuation is more obvious: I asked it to organize a spreadsheet on the phone, the task showed as running in the status bar area, and I could resume on the PC, but the intermediate status wasn't clear enough. I found it hard to judge if it was still running, finished, or stuck.

When I wrote about Agent tools previously, I said the core competition is no longer just whether the model can speak, but whether there is an auditable, accountable execution system. HyperOS 4's animations are light, thinking results auto-expand, and visual feedback is pleasing, but once cross-device errors occur, the causes are still too subtle. Is it network disconnection, device not logged in, permissions not granted, or files not indexed? Users find it hard to distinguish at a glance.

Scenario	What I encountered these two days	Judgment
Phone/PC conversation sync	Mostly connects, occasional delay	Worth enabling
Finding PC files via phone	Standard PDFs hit, messy names and sleeping PCs fail easily	Depends on file habits
Continuing phone tasks on other devices	Can resume, but status display isn't clear enough	Don't put critical tasks here yet
Device Center permission config	Many entry points, easy for beginners to miss	Enable slowly after upgrade

Official sources also mentioned that after 8 hours of continuous use on the Xiaomi 15 Pro, available memory increased by 27.2% compared to HyperOS 3. Is this data source reliable? The page cites Xiaomi Labs. This parameter isn't closely related to cross-device experience, but at least shows underlying optimization was done. Whether daily stability is better, I couldn't see obvious differences in two days, so I dare not endorse the lab's claims.

My conclusion is it depends. If you are a Xiaomi phone + PC user, often doing interviews, writing, and organizing materials, and habitually name files properly, this conversation sync and task continuation can reduce a lot of repetitive labor. Finding files on your PC via phone when the PC isn't nearby isn't a gimmick, provided the PC is online and files are indexed.

But if you only have one device, are sensitive about session sharing, or have folders full of "New Documents," I suggest not enabling everything fully. At least I would keep conversation sync but temporarily avoid handing over all local files for casual retrieval. The most valuable part of cross-device collaboration is context; the scariest thing is context being synced to places you haven't confirmed.

Going forward, I will observe two things: whether sync failures provide clear reasons, and whether the session scope between phone and PC can be seen clearly by users at a glance. Tool reviews fear functionality that seems understood until problems arise and responsibility boundaries cannot be found.