Single Port PCI Express x1 RS232 Serial Adapter Card - PCIe RS232 Serial Host Controller to Single Serial DB9 Port

As you know, relatively few PCs nowadays are equipped with serial ports yet many devices intended to work with those PCs provide only serial interfaces. USB-to-serial converters tend to be iffy, making this an inexpensive and useful little gadget. The octopus connectors are particularly valuable as there would otherwise not be sufficient space to allow four connections.The PCI-E card is quite small and will fit into limited spaces such as those tight areas resulting from installation of a big video card. As another reviewer pointed out, the connectors are numbered 1-4 but this does not mean that when you connect the adapter they are actually going to show up as COM1 through COM4. The presence of any virtual serial ports, for example, may alter the port numbering. The user in this situation may need to stick labels on the connectors identifying their actual port numbers.Installation was a breeze. On Win 7/64, one can just plug in and go. A driver disc is provided but my system found appropriate drivers on its own.Over recent weeks, I have connected multiple devices via the Syba 4x serial port card and each has performed correctly. Highly recommended.

Pros:* Small (full height bracket on half height board)* Inexpensive (equivalent boards can cost four times more)* PCIexpress 1x slot (small, tidy connector compatible with most modern motherboards)* Four-port breakout cable prevents using up another slot on the back (I could have put one in each PCIe slot)* Each DB-9M connector is labeled with a port number 1 through 4* No drivers or compilation needed on modern Linux operating systems (Fedora 13 in my case)* Works reliably with following devices: Kantronics KPC3+ Packet TNC, LaCrosse 2300 Weather Station, CyberPower PP1100VA UPS* DMA modes present if needed (I haven't evaluated them)Cons:* I can't think of any!Despite some anxiety and reports found on other product review sites that it might not work out of the box, or require modifications to the driver (which I could do, I am a Linux kernel guy), I was pleased to discover it works reliably out of the box with the stock Linux kernel (Fedora 13). I am totally satisfied.

I've been using usb to serial adapters since serial ports went the way of the dodo bird on motherboards but would occasionally have to unplug the usb adapter and find out the new serial port number.It worked right away with the kernel module was loaded.I had problems with my motherboard after about 3 days, but I think it was because the card was not seated properly. I'll give it a 5 if it's stable for a little longer.

I purchased two of these cards (two port models) to connect my fax server to serial modems. They worked out of the box on Debian GNU/Linux 8, and have been performing without issue for the past couple of months. The cards I received are using the MosChip MCS9922 chipset. Although not the fault of this card, I did have to make one adjustment to make all of the ports available to the system. Evidently Debian (and I think many other) distributions' kernels are configured by default to utilize a maximum of four serial ports. My server has two on-board, so only two more were enabled at first. I was able to fix this by adding the following to my /etc/default/grub file:GRUB_CMDLINE_LINUX_DEFAULT="8250.nr_uarts=8"After that, it's been smooth sailing. That kernel command line increased my maximum to eight ports, but I believe this can be set as high as 32. All this said, I would definitely recommend this card.

I bought this because my current computer does not have a com port and I was in the process of taking my CCNA exam and needed to configure a cisco router and switch. I had read that the usb to com cables sometimes dont work very well so I decided to buy this instead. It has two ports (I needed only 1), and so far it has run perfectly for the couple months that I have been using it. Drivers in Windows 7 were automatically installed. Solid Build, Solid Drivers, and no restrictions on configuring my router. Excellent Buy.