Sony A7 V: Wi-Fi Slow on One Device Only
Wi-Fi Slow on One Device Only on the Sony A7 V: what we found on our own £2499 unit, the checks that resolve it, and when it is a warranty case rather than a setting. Every other device on the network...
Priya Raghunathan
What is happening
Sony A7 V, burst 10fps mechanical, 30fps electronic. Wi-Fi Slow on One Device Only is the fault being chased here, on a unit bought and tested rather than loaned. It is genuinely good at ergonomics that have finally caught up, and the thing that repeatedly cost it marks was cFexpress Type A cards are overpriced.
Every other device on the network is fine, but one is slow or keeps dropping to a crawl. That is the behaviour; what follows is how it tends to present on this particular Sony, and what to rule out first.
First, a note: Work through these in order. The first two resolve the majority of cases and neither risks your data.
Start here
| Check | Why it matters |
|---|---|
| Is it reproducible? | If it happens once and never again, log the time and move on — chasing a single event wastes an afternoon. |
| Has anything changed? | A firmware update, a new app, a new accessory. The cause is almost always the most recent change. |
| Does it happen on a fresh restart? | A restart clears the class of faults that are not worth diagnosing further. |
| Is it under warranty? | The Sony warranty makes some of the steps below unnecessary — check before you start pulling things apart. |
The full procedure
- Forget the network on the affected device and rejoin, entering the password manually.
- Check whether it has joined the 2.4GHz band when 5GHz is available, which halves throughput in most homes.
- Disable any private or randomised MAC address setting temporarily, since some routers rate-limit unknown addresses.
- Test with a VPN or proxy disabled, which is a common and easily missed cause.
- Check for a firmware update on both the device and the router.
If none of that worked
If it is slow on a second network too, the radio or its driver is at fault rather than your router.
Keeping it from coming back
Give the 5GHz band a distinct name so you can pin devices to it deliberately rather than leaving band steering to guess.
Why it happens
In our experience this is rarely a single fault. The common pattern is an accumulation: a background process that was fine on its own, a setting changed months ago, and — on the Sony A7 V specifically — expensive, which narrows the margin before anything else goes wrong. That is why the steps above start with the cheap reversible checks: on a Sony device the expensive diagnosis is almost never the one you needed.
What makes it worse
- Do not change several settings at once — you will fix it without ever learning what caused it, and it will come back
- Do not install a third-party "optimiser" — on modern hardware these do nothing the operating system is not already doing
- Do not factory reset before backing up, and do not restore that backup immediately afterwards; if the cause is in the backup you have simply reinstalled it
- Do not leave it on charge overnight as a workaround for expensive — it treats the symptom and shortens the life of the cell
- Do not open the case while it is under Sony warranty; that is the one step you cannot undo
When it is a hardware fault
If the behaviour persists after a factory reset, it is worth raising with Sony under warranty rather than working around it. Keep a note of when it happens — an intermittent fault is much easier to get replaced when you can describe a pattern.
Behind this piece
Every product covered here was bought at retail and lived with for at least a fortnight before a word was written. Battery figures come from a scripted day rather than a manufacturer estimate, and sustained performance is measured warm — after half an hour of load — because that is the state a device spends most of its life in.
Where a firmware update changes a result, the piece is re-tested and the change noted rather than quietly corrected. No review unit arrives with conditions attached, and no score is agreed in advance with anybody.
Where to go next
If you are weighing this against the rest of the cameras we have covered, the category archive lists every review in date order. The closest comparisons we have published are Sony ZV-E10 II Review: Strong but Not Perfect and Sony ZV-E10 II vs Canon EOS R6 Mark III: Is the 2025 Model Worth the Change?.
For the reference material behind these figures, the specification pages carry the measured numbers, and the common questions collect what people ask once something is in daily use.
