MSI E350IA-E45 claims "PCI x16" on the box, but it only runs at x4! Legit?

Yesterday I purchased parts to build a new htpc. The board that I bought is the MSI E350IA-E45, which on the box boasts a single PCIe x16 slot. Not until I purchased and opened the box, and read the manual, did I find out that the x16 slot is limited to run at x4. So I'm a little angry, as I feel this was false advertising. I am actually not using this slot for anything right now, but might have in the future. I'm not looking for feedback such as "it's no big deal, you'll run fine at x4", or anything like that.. what I do want to know is:
- Is this normal practice for a manufacturer?
- What is the purpose of calling it x16 if it only runs at x4? My assumption is that it just means it can take an x16 card, but only run it at x4 speed? Shouldn't that have been specified on the box?
- If it can handle an x16 card, but is limited to x4, is that a hardware or software limit.. leading up to my next question - Can this limit be changed, either by the end-user (me), or by driver updates? Maybe they intend to unlock more speed later on??

Thanks in advance. Please go easy on me, I haven't worked with any modern hardware in the last 10 years or so!


Posts: 163   +29
I suppose the purpose of saying it is a x16 slot is to differentiate the size of the slot, x4 and x1 PCI-e slots are smaller. The lanes being x4, I'm not sure about, maybe due to the size and the expected use of the motherboard it was thought unnecessary, or maybe just to save cost.


Posts: 16,065   +4,868
Some low end boards don't run PCI-E 16 at full speed. But, as TekGun has said, "PCI-E x16" describes the socket, not necessarily the speed it runs.

Somebody can correct me if I'm wrong, but I believe you can run the smaller X1 board in the X16 socket, but not the other way around.

The PCI-E X 1 and X4 sockets are usually used for TV tuners and such, not video cards.

Here's a link to an add in tuner, so you can check out the PCI-E x1 interface:

Without digging out any paperwork to prove my point, I believe my Gigabyte Intel G-41 board runs the PCI-E x16 lane @ 4 X also. And this link to that board shows that I am correct:

I don't know how many post you need before you're allowed to insert links into a post. But, when you are able, you can link to the boards product page and we'll have a look.


Posts: 4,840   +1,264
Well here's the manufacturer product page. It does state 1 x PCIe x16 followed by "Gen2 (1x4)". Newegg page here similarly noted.
The Brazos chipset (third graphic on the page) is limited to four PCI-E lanes, so regardless of manufacturer the OP will get the same feature set. The bandwidth should be more than sufficient for a balanced system I would think. Any graphics card above lower-mainstream level which could suffer some bandwidth restriction will be more constrained by the APU's compute ability if it offered x8 or x16 lanes.
Four lanes, as cc outlined, is more than sufficient for sound card, tv tuner or slot based SSD (Revodrive).