There Were Two Keyboards on My Desk — I Compared Seven Best-Selling KVM Switches Before Choosing

2026年8月16日

6 August 2026

There were two keyboards on my desk.

Once you start with local AI, the machines somehow multiply. In my case a big PC with a graphics card in it ended up sitting next to a mini PC. One of them runs a model while I look things up on the other. Which means two keyboards and two mice. I only have one monitor, so every time I wanted to switch I was reaching round the back of the desk to swap the cable.

The device that solves this is a KVM switch. One button, and the monitor, the keyboard and the mouse all move over to the other PC together. I bought a two-port one first, then bought more PCs and replaced it with a four-port.

Choosing one took me a while, though. There are rows of similar-looking boxes, and prices run from about ¥2,000 to well over ¥10,000. What is missing from the cheap ones? (Prices here are Japanese retail as of August 2026; ¥1,000 is roughly $6.70.)

How many keyboards does a desk need?

First, what the actual problem was.

A local AI setup does not always fit on one machine. The machine that runs the large model and the machine you work on can end up being different boxes. Mine became two: a PC with a graphics card, and a mini PC with a lot of memory.

When that happens, three things start going on around your desk.

The third one may be particular to local AI. Model files run to tens of gigabytes, so they travel between machines on an external SSD or a USB stick. Having the destination change each time was quietly annoying.

Are there different kinds of switch?

This was the first fork in the road. Things sold as “switches" come in two kinds, and what they switch is different.

Shopping without knowing that distinction gets confusing, because the most-reviewed switch on Amazon is the KM kind.

Elecom’s KM-A22BBK had 3,196 reviews at 4.3 stars (checked 6 August 2026 on the Japanese store). Everything else sits somewhere between a few dozen and 300, so it is an order of magnitude ahead. But it is a keyboard-and-mouse switch. The monitor stays where it is.

What I was after was something that would share the monitor and the USB devices together. So the popular choice was not for me. Not because a big review count is bad, but because it was answering a different question.

Turn it around, though: with two monitors and two PCs, the KM switch is the more straightforward answer. No video goes through it, so the “4K60 will not come through" problem discussed below never arises in the first place.

Which ones are selling?

On 6 August 2026 I sorted Amazon by what was selling and worked through the list. Prices, ratings and counts are all from that day. The two I own are in the same table for comparison.

Width is filled in only where the product page actually listed a dimension. Two of them did not. That comes back later. And the supported resolutions are the manufacturer’s claims, which is not the same as what comes out the other end. That comes back later too.

Price against port count was fairly honest: two-PC models at ¥2,000–3,000, four-PC models at ¥6,000–7,000. Only the triple-display one stands apart, at ¥12,000-plus.

What do you get for the extra money?

I wanted to know what the price gap actually buys, so I read the low-star comments on each. This was the most surprising part of the whole exercise.

Price and lifespan had very little to do with each other.

Review sections are of course skewed towards people with a complaint. Those whose switch just works do not write in. So this is not “they all die in a year."

Still, the same kind of failure report shows up at every price point, and that felt worth knowing before buying. This does not seem to be a category where paying more buys peace of mind.

So what does the money buy? From the comments, not longevity but the number of things it can do: how many PCs, what resolutions, how many USB ports, whether there is a remote you can reach. Add those and the price climbs.

My own two showed the same pattern. The ¥2,000-class box was unreliable at 4K60Hz; the ¥7,000-class one displays without trouble. The price bought signal quality, not service life. More on that below.

What did I actually choose on?

Three things, and they sit slightly off from what the spec sheets lead with.

One: it has to share the monitor and the USB devices together

I only have one monitor, so the picture had to switch along with everything else. That is what put me on KVM switches.

I also wanted the USB devices to travel: not just keyboard and mouse, but external SSDs and USB sticks too. With local AI you are carrying model files around, so this matters.

One warning. Products count their USB ports differently. A comment on a UGREEN product puts it well.

Reading “USB-A 3.0 x3, USB-C 3.0 x1" you would assume all of those ports are yours to use, but in reality two of the USB-A 3.0 ports are the inputs from the PCs, and what is left for your own devices is one USB-A 3.0 and one USB-C 3.0

So “four USB ports" can mean two ports you can actually plug into. The rest go to the PCs. Fill two with a keyboard and mouse and there is nowhere left for a USB stick. You have to read which end each hole is for, not the number.

Two: the USB ports need to be on the front

This one only mattered once I knew how I would be using it.

My keyboard and mouse are wireless, the kind with a receiver dongle. The little Logitech receiver lives permanently in the USB port on the front of the switch.

Set up that way, pressing the button moves the keyboard and mouse to the other PC along with the monitor. A wireless keyboard that switches exactly like a wired one. Obvious enough once you see that a single receiver is being shared, but it is a satisfying thing to use.

Do the same thing with a rear port and the receiver ends up buried behind the desk, with the desktop and the chassis in the way of the radio path, and you are reaching round every time you want to move it. Whether there is a port on the front changes the experience if you use a wireless keyboard.

Same story for USB sticks and external SSDs. Things that stay plugged in can live at the back, but anything you take in and out belongs at the front, or you are back to reaching behind the desk.

Port placement is usually not something you can read off the product page. Dimensions and supported resolutions are listed; which side the USB ports are on is not. Zooming into the product photos and finding a straight-on front view is the reliable way.

Three: it has to be no wider than a Mac mini

A question of where it goes. The switch has to sit on the desk, within reach. Hide it behind something and the remote loses its point, and you cannot get at the USB ports.

So I used the Mac mini as my yardstick. The Mac mini M4 is 12.7cm wide. Anything about that size will not be in the way.

Why I moved from two ports to four

The first one I bought was a two-port Lemorele, at ¥2,369.

It turned out to be surprisingly pleasant, and I used it for a good while. Nothing about it got in the way, for the money. Buying the cheap one to see what happens, and getting a good result.

The reviews did flag a couple of things about it, though. There is no remote, so you have to reach over to the unit to press the button. And there were reports of 4K60Hz not displaying.

I bought this to switch PCs at 4K60Hz (HDMI 2.0). I used HDMI 2.0 cables throughout, but at 4K60Hz the screen kept cutting in and out and I could not use it. […] At 4K30Hz (HDMI 1.4) it displayed with no problem

The same thing happened here. At 4K60Hz the picture came and went. After a few attempts I dropped to 4K30Hz, which was stable, and used it that way.

What I had read in a review section turned up on my own desk. Perhaps there is no headroom for 4K60Hz at this price. For Full HD or 4K30Hz it caused me no trouble, but if you buy it expecting a high refresh rate you will be disappointed.

Then I acquired more PCs, and two ports were not enough.

I replaced it with an ELEVIEW EHD-810N: four ports, ¥7,115. It claims 8K60Hz and 4K120Hz and comes with a wired remote you can keep by your hand. And at 13.0cm wide, it comes out about the same size as the Mac mini.

In fact I had been running it at 4K30Hz right up until writing this. After the trouble I had at 60Hz on the previous box, I had left well alone once something worked.

Since I was writing anyway, I switched it to 4K60Hz. So far, no ill effects. No flickering in and out; it simply works.

That said, I changed it only just now, so I cannot speak for the long run. And my monitor tops out at 4K60Hz, so anything above that I have no way to test. The 8K60Hz and 4K120Hz this product advertises are both unverified here. Of the resolutions in the table, 4K60Hz is as far as I have confirmed a picture.

To be straight about it, this product sits at 3.2 stars with only 13 reviews. On the numbers alone it is a nervous pick. The comments include a remote that did not work out of the box, and one that failed after six months.

On the other hand, there are people who bought it the same way I did.

My desk was getting unmanageable as the number of PCs grew, so I moved from a 2-input switch to a 4-input HDMI KVM. […] Now I switch one keyboard, mouse and monitor across four machines, the desk is clear and I get a lot more done

Looking back, I should have bought the four-port from the start. The ¥2,369 was not wasted exactly, but if you can see more PCs coming, leaving yourself headroom on ports works out cheaper.

Do local AI and the machines multiply. Start out intending otherwise and they multiply anyway.

What to check before you buy

Here is what I looked at, in the order it is worth checking.

• Do you need the monitor to switch too? One monitor means a KVM switch; two monitors already wired to each PC means a KM switch is enough
• How many machines will there be? Two today, but if more are coming, a four-port is worth considering now
• How many USB ports are yours? The advertised “four ports" can include the ones that go to the PCs
• Are the USB ports on the front? Put a wireless receiver there and the keyboard and mouse switch along with the monitor. At the back you lose both radio path and convenience
• How wide is it? Decide where it goes first and you save yourself trouble. Some products do not publish a dimension at all
• Is there a remote? Essential if you want to tuck the box out of sight. Not all of them have one
• Do you need above 4K60Hz? The label is not a promise. On my desk the ¥2,000-class box was in and out, and the ¥7,000-class one was fine. If this is non-negotiable, either move up a price band or buy where you can return it
• Assume it will break. Every price band has people reporting about a year. Paying more did not buy safety
• The USB cable to the PC is not a standard shape (Type-A male at both ends). Nearly every product does this, so it is hard to avoid, but it is better to know going in
• Connecting a Mac needs one adapter. A Mac mini has no USB-A socket, so you need a separate USB-A to USB-C adapter. Video connects over HDMI as normal

Where do people trip up?

Reading through the comments, three things looked likely to catch a first-time buyer.

It needs both HDMI and USB connected

Each PC needs two cables to the switch: an HDMI cable for the picture, and a USB cable to carry the keyboard and mouse. A fair number of people connect the HDMI only and then report that the mouse does not work.

So that is two cables per PC, eight of them converging on a four-port switch. There are more cables involved than you picture.

Connecting a Mac takes one adapter

I did not notice this one until I went to plug it in.

As above, the USB cable between switch and PC has the flat connector (USB Type-A) on both ends. A Mac mini has no flat socket. What it has is the round ones: USB-C and Thunderbolt.

So the Mac end needs a USB-A to USB-C adapter in between. It is not in the box. It costs about ¥1,000, but without it the keyboard and mouse will not follow you to the Mac.

The video side is fine. A Mac mini has an HDMI socket, so that connects as it is. It is only the USB side that comes up short.

The mildly funny part is that this puts an adapter on the end of a cable the standard does not allow in the first place. As engineering it is not a comfortable arrangement. It works fine here regardless. If it bothers you, you can look for a switch that connects to the PC over USB-C, but the list of candidates gets a lot shorter.

The USB cable is not permitted by the standard

This is the part that bothered me most.

The USB cable between the switch and the PC has the same connector at both ends: a male USB Type-A on each side.

That cable is not permitted by the USB specification. A Type-A connector is defined as the socket on the host side, and feeding power in from both ends was never the intent. They are sold anyway, but they are not compliant.

Someone in the comments had the same concern.

Because the PC-side USB is Type-A, connecting to the PC means an out-of-spec A-to-A cable. That could be awkward if you ever lose the supplied cable, hence the lower rating

This is not specific to one product, though. KVM switches as a category are built this way. Avoiding it means hunting for a model that connects to the PC over USB Type-C, and the choices narrow sharply.

For my part, it bothers me and I have had no trouble with it so far. Nothing has broken or caught fire. But replacing the supplied cable would be a nuisance, and it is worth knowing you are using something out of spec. Keep the cable that came in the box.

Units seem to vary

Several reports of “one of the two HDMI inputs was dead on arrival." When yours turns up, check that every PC you intend to connect actually displays, while you are still inside the return window.

In summary

Two keyboards on one desk is a problem you can fix for about ¥2,400. In my case more PCs arrived and I moved up to a four-port, but the desk is in far better shape than where it started.

What I chose on was not the line at the top of the spec sheet. It was whether it shares the monitor and USB together, whether the USB ports are on the front, and whether it fits on the desk. Those three.

And spending more does not appear to buy you a longer life. In that case, choosing on the port count you need and how it feels to use day to day is the purchase you will be happy with.

Products covered in this article

The kind where the monitor switches with everything else (KVM switches).

The adapter you need when connecting a Mac.

And if keyboard and mouse are all you need to switch (a KM switch).

Sources

Prices, ratings, review counts and dimensions were all checked on Amazon product pages and review sections on 6 August 2026, on the Japanese store, so the figures are Japanese retail; dollar equivalents are at roughly ¥1,000 = $6.70 and are for scale only. The Mac mini M4 dimension comes from Apple’s product page. Product availability differs by country, so the links here point to equivalent products rather than the identical listings I bought from.