Max speed per sata connector on pcie 2.0 x4?

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I've seen other controllers, but this one specifically states each port is only 520mb/s. Is this also true of all other devices like this? I was assuming they could all reach the 1000mb/s that the pcie slot could reach. (plus reviews said it had problems with introducing errors.)

I have an 850 pro samsung ssd that can go up to 900mb/s reads and 550mb/s writes. I need at least that. Would other cards have this restriction?

Does anyone know of a PCIE 2.0 4x card that can get 900-1000mb/s or more per port?

I have this mobo: https://www.gigabyte.com/Motherboard/GA-970A-D3-rev-10-11#ov

I beleive it does at least 1.2gb/s per port. I'm looking for a sata card that does that speed or a sata raid card that can take 6 sata disks in raid 10 at max speed.

Actually, I have to get a place for either some of the raid disks or for both my SSD and a seagate ST2000DM008 to have full throttle on. Is it ok to have disks in a raid on different disks? It's software raid. Would the first card be capable of handling those fully? The raid consists of 6x https://gzhls.at/blob/ldb/7/6/1/e/ee7a79edc97b885933949eeefdb2d9fbdf1b.pdf

I could possibly stick two of the raid drives on a pcie x4 and the main ssd on the mobos disks. But then I can't try to run hardware raid to see if it's any good.
 
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Something is wrong. PCIe 2.0 standard is 500 MB/lane. So x4 = 2 GB and 16x = 8 GB. That's the standard, that's all it supports. PCIe 2.1 is also the same 500 MB/lane.

[reference]
 
Is it because it's stacked ports somehow? I'm assuming it's sharing it or something.

Would the other devices get the full 1gb both directions? I'm assuming the 2gb is read and write simultaneously at half speed each(1gb/sx2).
 
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IIRC, you're correct in that it's 500 MB/lane *cumulative*, so theoretically even distribution would be 250 each way.
 
I found this technical manual: https://m.media-amazon.com/images/I/71uwH5-MKrL.pdf
It says:
EachPCIExpress2.0laneprovidesupto400MB/softhroughput.
The other boards ahve a 400mb/s listing. Is this an older model with more limitations. Or is this normal for pcie 2.0?


It also has this:
ZYT-SA30061ProductIntroductionThisboardisequippedwithASM1062(PCIEtoSATAController)+ASM1093*2(PortMultiplier),PCIExpresstoSixSATAGenIII6Gb/schannelshostcontrollerthatbringsserver-classfeaturestothedesktop.
It sounds like this is claiming it gives 900mb/s slot with 520mb/s port speeds. but why is this limited? It sounds like this was made when pcie2.0 first came out. Do later cards like this have this same limit and don't say or do they get the full 1000mb/s per port both ways? I've never heard of this restriction before. Is this to do with the onboard chip or something?


I wonder if this would get full speed. Or is 520mb/s the max speed?


This one says it has the same restriction of 520mb/s at 2.0...


This seems to indicate it might be encoding that speeds it up from compression... So, it is different per chip? Are there any that get full use of the slot speed? Or do the all work similarly. I'm hoping others have better compression or whatever it is supposedly causing this.

I'm assuming my sata slots native on my motherboard don't have this problem. The read speed and sequential for my motherboard via the SSD were maxed at around 900mb/s and the actual board speed max I think was around 1.2gb/s. Although, I could have measured the wrong thing.

Is this a wireing limit to sata or is it the chip not allowing full use of the slot?

Is it also a limit to pcie 3.0 boards back using 2.0 boards either from the chip limit or something else? Or am I misunderstanding this? Which I'm assuming is likely. Is it possible pcie 2.0 designed boards don't have the limit because they use better compression and 3.0 don't have to bother and have a performance drop?!


At the bottom this says it was used for pcie 1.x and 2.x. not sure if the encoding increases or decrease bandwidth though.

Or is it the opposite and the pcie 2.0 designed ones decrease bandwidth. It also says sata and sas use the encoding... I'm completely confused about all of this. Which if any gets bi directional 1000mb/s per port?
 
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