AmigaOne X5000 PCIe Slot Questions

I was informed that the AmigaOne X5K 16x slot has only 4 lanes and thus the speed of a 4x slot.

#1, is this true?

2nd, I asked if the 4x slot is really a 4x or something less and was told they believe the 4x slot is only 1 lane and thus 1x speed.

Does anyone know for sure about these two questions?

Thanks

TJ

@AmigaSociety

If you want to know something technical about your X5000 then you could also check out the X5000 TRM yourself. If you don't have it then you can download it here: https://amigaone.files.wordpress.com/2 ... /trm_cyrus_1-1-1_aeon.pdf

But to answer your questions:

1. The X5000 x16 slot is directly connected to the P50x0 with 4 PCIe2.0 lanes. This means a bandwidth of 2000MB/s

2. The x4 slot is connected with 4 PCIe2.0 lanes to a PCIe switch. Which is in turn connected with 4 PCIe2.0 lanes to the P50x0. So also 2000MB/s. But a bit higher latency due to the switch.

"Just" 2000MB/s is no issue at all. Various tests on PC websites reveal that the difference in fps between PCIe2.0 x4 (2GB/s) and PCIe3.0 x16 (~16GB/s) is just a few %.

@geennaam

Cool, thanks for the answers.

I did look at those files but was unclear how to read as I am just not that knowledgeable on how to read it, I must admit.

Example, I was clueless about switch lanes. The 0,1,2,3 for the 16x made sense but after that I got lost.

Thanks for the notes as that clarifies it for me.

TJ

@AmigaSociety

Yes, it is a bit cryptic. The thickness of the line to the x4 slot already suggests multiple lanes. Compared to the thin line of the x1 slots.

I know for sure because I use the x4 slot for my Nvme driver and can confirm that indeed 4 lanes are connected. But you can also check out the connector pinouts. There's only a remark for the x16 slot that lanes 4-15 are not connected. There is no such remark for the x4 slot.

@geennaam

and even more cryptic to folks like myself, lol.

Thanks for the notes.

TJ