Why we need PCIe x1?

[life24]

Hello,
Why we need PCIe x1 or x4 or x16?
Why not make everything based on 16? Is not better?

 

[UsandThem]

Because not everything needs 16x slots. Pretty much only GPUs do right now, and consumer CPUs limit the number of PCIe lanes. So it would suck only to have two PCIe slots on an ATX motherboard.

 

[ElFenix]

the boards would be more costly as you'd need more layout engineering for all those lanes and the cost of building them, and chips would need more pins further increasing cost. or, even if you were using switching chips on the board instead of native cpu lanes, you'd have to add that cost in.

and last time i went to check, even the most top of the line graphics cards aren't bottlenecked by x8. nothing comes close to needing the bandwidth available from an x16 slot today.

 

[Charlie22911]

It would be nice if all slots were electrically x16, but could negotiate number of lanes based on available supply. But to be fair, the vast majority of consumers don't have a need for that kind of added complexity. I can't imagine many people are building home servers with consumer gear and trying to fill every expansion slot (I'm in that minority).

 

[whm1974]

It would be nice if all slots were electrically x16, but could negotiate number of lanes based on available supply. But to be fair, the vast majority of consumers don't have a need for that kind of added complexity. I can't imagine many people are building home servers with consumer gear and trying to fill every expansion slot (I'm in that minority).

And that is why MicroATX and MiniITX builds have gotten popular.

 

[dsplover]

I only need a single PCI-e 1X slot for high end audio processing.
I love H97 Supermicro and ASRock Server Boards.
The new Q370s with i3-8350-8086k are going to be a great upgrade.
I like the single PCI-e 16X designs on ITX boards too.
Stick my Ribbon Extender for 1X into it no problem.

My gaming PC or HTPC are all mATX too.
I build those as well but was tempted for the Corsair Bulldog barebones. A fantastic chassis.

 

[Ratman6161]

It would be nice if all slots were electrically x16, but could negotiate number of lanes based on available supply. But to be fair, the vast majority of consumers don't have a need for that kind of added complexity. I can't imagine many people are building home servers with consumer gear and trying to fill every expansion slot (I'm in that minority).

I'm in that boat too and have an old FX8320 on a 990FX board. But even for my home ESXi lab I don't really need x16. The main items I've got that are a little different from your run of the mill PC are an LSI RAID card that's x8 and a dual port Intel NIC that's an x4.

Lately i've been looking to take an unused Ryzen 5 1600 and Asrock AB350 Pro 4. The biggest issue for someone who doesn't quite understand how it all works is figuring out what to put in what slot such that everything actually runs at ite rated speed. For me that's where an x1 slot comes in. I found an x1 graphics card on Amazon. So I don't need either of the full length slots for graphics. So the x8 RAID card goes in the x16 slot where a graphics card would otherwise be. On this board that means the second full length slot is limited to x4...but that's exactly what I need for the dual port NIC.

 

[dsplover]

Which 1X GPU did you get.
I might do an AMD build and it.

I can stick my Audio 1X connector to 16x and it just drops the rate of the slot to accommodate it.

 

[DaveSimmons]

I've used a second PCI-E slot exactly once since they were first introduced, to use an adapter to read a nvme drive on an older motherboard that had no nvme slots.

I needed a physical x4 slot for that, but only for one day over 10-15 years. I now have 2 PCs with nvme slots and eventually there will be decent USB3 adapters for PCI-E nvme so that's probably the end of my use for another 10 years.

I'd rather motherboard manufacturers not waste extra money on making more than 2 of the slots x16, x1 for any others is fine.

 

[IntelUser2000]

Hello,
Why we need PCIe x1 or x4 or x16?
Why not make everything based on 16? Is not better?

Because nothing is free. Increased amount of lanes require additional die taken up in the chipset/CPU.

Increased data lanes also mean more traces on the board, which increases cost(and motherboard business is known for having razor thin margins).

Also, some things don't require bandwidth above x1. Heck, for some things like networking, even x1 is overkill. 5Gbit networking cards can use x1 slots.

 

[whm1974]

Because nothing is free. Increased amount of lanes require additional die taken up in the chipset/CPU.

Increased data lanes also mean more traces on the board, which increases cost(and motherboard business is known for having razor thin margins).

Also, some things don't require bandwidth above x1. Heck, for some things like networking, even x1 is overkill. 5Gbit networking cards can use x1 slots.

Come to think of it, even high end GPUs don't even use the full amount of bandwidth of the PCIe x16 slot. In fact x8 would be fine with no loss of performance.

 

[LTC8K6]

Come to think of it, even high end GPUs don't even use the full amount of bandwidth of the PCIe x16 slot. In fact x8 would be fine with no loss of performance.

I suspect that possibly that has ended with the new NV cards?

 

[whm1974]

I suspect that possibly that has ended with the new NV cards?

Maybe with the 2080 Ti?

 

[bigboxes]

Hello,
Why we need PCIe x1 or x4 or x16?
Why not make everything based on 16? Is not better?

I have four full sized PCIe slots on my mobo. Three are x16 and one is x8. Unless you wanna pay through the nose for that mobo, I really don't think you want it as much as you think. <paste IntelUser2000 post here>

 

[slashy16]

I honestly don't see the need for any slots other than a single 16x. Ever since I ditched raid using an LSI controller I have had no need for any slots other than a single 16x. I can't think of anything outside professional use or streaming which would require a second card.

 

[whm1974]

I honestly don't see the need for any slots other than a single 16x. Ever since I ditched raid using an LSI controller I have had no need for any slots other than a single 16x. I can't think of anything outside professional use or streaming which would require a second card.

I rather have a few extra PCIe slots for just in case I need them. But historically since I since I built my first system in 2000, I only needed two slots, one for the video card and the other for a sound card. Although I did use a video capture card for a few years. Now the only card I have installed is the dGPU.