PCIe 2.0 controller on PCIe 1.0 x16 slot

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I think the question has already been answered as to if it will work. Here is what he asked however.

Will a PCIe 2.0 x1 or x4 SATA III controller card work at full speed in a PCIe 1.0 x16 slot?

I'm going to with no, sort of. Will it fit/plug in, yes. Been answered already. I'm assuming you are replying the way you are because you want to know how much slower it will be in a 1.0 slot. This is hard to answer because bandwidth != speed. Just because you are on a freeway with a 65MPH speed limit doesn't mean you can go that fast. (like your 35MPH top speed moped.) You'll be fine with normal hdds, but SSD read/write speeds will be very limited.

weaselman

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It sounds simple, but sometimes not. for example a Graphics card can be of a 2.0 Pci-standard or a 3.0 Pci-e standard, these cards have a fall back mode to the different standards. Pci-e 1.0. so it may not function exactly as expected, depending on the card you buy check to see it the cards support lower revisions of Pci-e slots first if you can.
Just to be safe. I have known some people have problems for example simply because the card is not picked up by a pci-e 1.0 slot since it could only run on a 2.0 spec Pci-e version.
 

4745454b

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I think the question has already been answered as to if it will work. Here is what he asked however.

Will a PCIe 2.0 x1 or x4 SATA III controller card work at full speed in a PCIe 1.0 x16 slot?

I'm going to with no, sort of. Will it fit/plug in, yes. Been answered already. I'm assuming you are replying the way you are because you want to know how much slower it will be in a 1.0 slot. This is hard to answer because bandwidth != speed. Just because you are on a freeway with a 65MPH speed limit doesn't mean you can go that fast. (like your 35MPH top speed moped.) You'll be fine with normal hdds, but SSD read/write speeds will be very limited.
 
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clutchc

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I guess full speed has different meanings for different folks. 4745454b says it best. It will operate at the full speed of the card's capability as long as the card's capability doesn't exceed the bandwidth of the PCIe X16 1.0 slot: 4 GB/s (40 GT/s) in each direction.
 

digityzed

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BINGO! I was worried I was wording my question wrong.

So, basically the PCIe 2.0 x1/x4 card on the PCIe 1.0 x16 slot will possibly...:

[1] run comfortably at 500 MBps/2000 MBps under 4000 MBps (PCIe 1.0 x16)
[2] run comfortably, barely, at 500 MBps/2000 MBps under 2000 MBps (PCIe 1.0 x8)
[3] drop from 500 MBps/2000 MBps to 250 MBps (PCIe 1.0 x1)
[4] not run at all

...??
 

4745454b

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You said it was a 4x card. I don't know why people are listing the full 16x speed as you'll only be using 1/4th of the possible lanes. Maximum speed would be 1/4th of the 4000MBps. It will work, but it won't be running at full 16x speed because its not a 16x card.
 

digityzed

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So when PCIe devices drop back due to incompatibility they're only going to do so to the next available version (i.e., 2.0 to 1.0) but stick to the same number of lanes (i.e., 4x to 4x)? And if those lanes aren't available on the mobo slot, they can only drop down lanes (i.e., x4 to x1) and CAN'T switch to higher lanes on a lower PCIe version (i.e., 2.0 x4 to 1.0 x16)?
 

clutchc

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Pretty much, yes. But the number of lanes is a physical characteristic of the slot. The lanes relate to the number of wired contact points the slot contains. For instance, some PCIe X16 slots are only x4 electrically. If you turn the MB over and look at the solder traces on the back, you'll see that only a portion of the long x16 slot is 'wired'.

Normally the longer the slot, the more lanes it contains. The only exception I'm aware of is the the x16 slot as mentioned above.
 
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