I would suggest something like this: https://www.asrockrack.com/general/productdetail.asp?Model=ROMED4ID-2T#Specifications - actually there isn't anything else like it quite frankly.
Then use C_Payne's slimline cards for the GPUs...
One more test, doubled the cable length to 75cm, and replaced the active carrier with passive, just in case I was hanging on by a thread.
Still got full gen 3 speeds ;-)
It's built! Soldering down the OCuLink connector was a bit more trouble than I was expecting but figured it out eventually. Smashed it in the benchmark, full Gen.3 performance achieved (don't have anything newer, but doubt it'd work anyway).
Using an OCuLink to PCIe adapter is a pretty...
New board coming soon. Similar to C_Payne's larger and better designed slimline adapters, but for non GPU use (apologies if anyone is still reading, and getting bored of these posts ;-)
It's a compact OCULink x4 to PCIe x8 (mechanical) adapter. I don't have all the 3D models so some imagination...
And there we go. Finally...
Works brilliant! Two PCIe cards in a case designed for one. Quite a bit of metalwork in all of that, but it all worked out well in the end. Mezzanine PCB has a 0.5mm offset error (not too surprising as I hadn't decided on the exact position of the card).
As I said...
Off to a good start. x8 and M.2 working good. Booting from my sacrificial sabrent, with a SAS 2308 in the X8 slot.
Now we get to the tricky bit, running an x4 from the left hand 3.5" bay. Going to be a bit of a job to build all of that. Watch this space...
The DHL van has been and gone, and it's new riser day again today. This is my first physical build of the other riser I showed on the previous page. The Mezzanine PCB is shown in position but isn't electrically attached yet.
I'm hoping this one will be a slam dunk. My previous riser's schematic...
One last shot for the road. Installed in the case.
Well this has been an interesting journey. I've now got M.2 SSD and 10GbE - a previously impossible combination with this case / mobo. I actually can't remember the last time I designed a PCB that didn't have to be revised. These were made blue...
Well that went quicker than expected. Must have done something right! Got a Sabrent Rocket and 10GbE SFP+ NIC working on it.
Not a bad start for a 2 layer board. Will have to give it a bit of a thrashing...
Which cabling? I have no idea. Pick any PCIe GPU riser you can shake a stick at, it's probably using this stuff, even if it's covered with something else.
I've got three here from different brands, all the same cable. It's marked "E209277 AWM 21283 30AWG 80°C 30V FT2 3A GERMANY PATENT 20 2007...
My first riser now exists. It'll be some time till I try it out.
The good so far: It's mechanically bang on. Fits in the case perfect, x4 slot is in the right place, M.2 drive screw spot on.
The bad: It's tremendously difficult to build. The ribbons are hard to strip and prepare, and even...
I notice you've been busy with redriver boards. Are those required on risers for Gen.4 ?
(EDIT: He did try Gen.1 so probably something else wrong here)
Just for good measure, here's another riser for C146, C159 and T1160. Swapping the bottom x4 slot for M.2. I'll build this one too and see how I get on with it.
PCIe design tolerances are typically System Board -> Properly designed riser -> Peripheral. If you put anything more in the mix you'll have too much signal loss/jitter/reflections and it's not likely to work.
Running PCIe over USB isn't supported by any of the PCI-SIG standards thus there are...
I can see the benefit. It hard to run a 6/8/6 pair between pads on a slot unless they have almost no copper left on them. Am a little concerned about this is going to pan out in practice. We'll see in the coming months I guess.
You're the guy who does it right, I'm the guy who does it cheap!
The cable I'm using is designed for PCIe and is said to have the correct impedance, although I've not found a detailed spec for it. The PCB is the potential issue, but I checked in the calculator and bumping from 0.2mm of dielectric to 1.4mm doesn't make a lot of difference. It's still within...
Just hammered out another riser. This one is for Travla/Casetronic models C146, C159 and T1160. It's an x8 to x4x4 (that is what I need at the present time). It's is built in the form of the original Conventional PCI riser connected by ribbon cables as this was a better choice practically and...
You are probably right source termination with no AC coupling is fine. I have the gear to eye diagram the clock so not too worried about it.
It's the data pairs that I'm more concerned about. I don't have the kit to eye those. Just going to have to get it right, or beg to borrow it.
Hey folks. Inspired by C_Payne's elegant designs, I've decided to have a crack at designing my own riser.
This one is for the Casetronic T9120 to replace the manufacturer x16 riser. I will be making it available to others if it succeeds. I have a few other casetronic risers I want to do too...