(AI translated, from 2022.02)
I have already written that I use many small disks. Together with the remaining large disks, it totals 10 disks. And I have always wanted to use some fancy RAID controller. However, no matter how many controllers I put into the spare PCIe (x8) slot, none of them worked, the computer didn’t even start BIOS
It’s a physical x16 slot, but it only has x8 lanes electrically. This is common in household computers – the first long slot is for the video card, x16, and the second is only x8.
The x8 isn’t a problem, as RAID, SAS, and SATA controllers were all x4 or x8. But all of them refused to work. Although, the second video card (x16) or even a dual network card (Intel® 82571EB 2x1Gb, x4) worked perfectly in this slot… The video card reported that it was working on x8. I didn’t ask the network card.
Even taking something as simple as a JMicron Technology Corp. JMB585 and plugging it into that slot, the computer doesn’t start. What’s the issue?
Although mechanically it’s an x4 slot, electrically it’s only x2. I haven’t seen x2 PCIe slots. Reading the chip’s datasheet, I came across the line ‘Supports up to two lanes of PCI Express’, which means it doesn’t necessarily have to be x2, x1 is also fine. My computer’s x1 slot doesn’t physically accept longer cards (and the ID line on this card isn’t connected to x1), but trying to connect through a PCIe riser, everything magically works:
Indeed, the other end is plugged into a free x1 slot.
Now the question. Why don’t the directly connected cards work? Too few free PCIe lanes? Misconnected ID lines on the cards or the motherboard? What’s the issue? And will this SATA-PCIe ‘bridge’ work if I mechanically cut the PCIe slot and connect the ID contact?
If anyone comments that the disk speed will be very low, my answer is – I know, those disks are only used for background backup copying.
2024 EDIT. All the problems were from shitty mainboard. Using new, i7-14K based system everything is OK. Simple, the system was to old for my experiments.
