A M.2 HDMI capture card
31 comments
·April 21, 2025viccis
Numerlor
The vast majority of people run just one gpu, which motherboards have a dedicated direct to CPU x16 slot for. Stealing lanes comes into play with chipset connected slots
zten
I bought a Gigabyte X870E board with 3 PCIe slots (PCIe5 16x, PCIe4 4x, PCIe3 4x) and 4 M.2 slots (3x PCIe5, 1x PCIe 4). Three of the M.2 slots are connected to the CPU, and one is connected to the chipset. Using the 2nd and 3rd M.2 CPU-connected slots causes the board to bifurcate the lanes assigned to the GPU's PCIe slot, so you get 8x GPU, 4x M.2, 4x M.2.
I wish you didn't have to buy Xeon or Threadripper to get considerably more PCIe lanes, but for most people I suspect this split is acceptable. The penalty for gaming going from 16x to 8x is pretty small.
ciupicri
For a moment I didn't believe you, then I looked at the X870E AORUS PRO ICE (rev. 1.1) motherboard [1] and found this:
> 1x PCI Express x16 slot (PCIEX16), integrated in the CPU:
> AMD Ryzen™ 9000/7000 Series Processors support PCIe 5.0 x16 mode
> * The M2B_CPU and M2C_CPU connectors share bandwidth with the PCIEX16 slot.
> When theM2B_CPU orM2C_CPU connector is populated, the PCIEX16 slot operates at up to x8 mode.
[1]: https://www.gigabyte.com/Motherboard/X870E-AORUS-PRO-ICE-rev...
elevation
Even with a Threadripper you're at the mercy of the motherboard design.
I use ROG board that has 4 PCIe slots. While each can physically seat an x16 card, only one of them has 16 lanes -- the rest are x4. I had to demote my GPU to a slower slot in order to get full throughput from my 100GbE card. All this despite having a CPU with 64 lanes available.
doubled112
The real PITA is when adding the NVMe disables the SATA ports you planned to use.
throwaway48476
New chipsets have become PCIe switches since broadcom rug pulled the PCIe switch market.
gruez
>broadcom rug pulled the PCIe switch market.
What does this mean? Did they jack up prices?
nyrikki
Avego wanted PLX switches for enterprise storage, not low margin PC/server sales.
Same thing that Avego did with Broadcom, LSI, Brocade etc... during the 2010's, buy a market leader, dump the parts that they didn't want, leaving a huge hole in the market.
When you realize that Avego was the brand produced when KKR and Silver Lake bought the chip biz from Agilent, it is just the typical private equity play, buy your market position and sell off or shut down the parts you don't care about.
Venn1
The website is wheezing a bit. Here's a link to the video https://www.youtube.com/watch?v=xNebV8KIlZQ
0cf8612b2e1e
If I wanted to capture something with HDCP, what’s the most straightforward path to stripping it away?
ec109685
Reddit says [1] this works: https://www.amazon.com/dp/B08T62MKH1?ref=ppx_pop_mob_ap_shar...
I bought this a while ago and it works: https://www.amazon.com/dp/B004F9LVXC?ref_=ppx_hzsearch_conn_... (but is no longer available)
[1] https://www.reddit.com/r/PS3/comments/1fjbzrz/comment/lp93nd...
kodt
HDFury has multiple devices that can do it, but they are fairly expensive. Many of the cheap HDMI 1x2 splitters on Amazon also strip HDCP on the secondary output. You can check reviews for hints.
null
baby_souffle
There are various splitters and mixers that have the necessary edid/hdcp emulator functions.
I don't know if anybody has managed to figure out how to defeat hdcp higher than 1.4 though.
mistersquid
> I don't know if anybody has managed to figure out how to defeat hdcp higher than 1.4 though.
This works for me: https://www.amazon.com/dp/B08T64JWWT
mschuster91
Aside from the high number of 1-star reviews complaining about the gadget dying fast - how in god's name is this thing still selling assuming it can actually strip HDCP for modern HDMI standards?
I'd have expected HDMI LA to be very very strict in enforcing actions against HDCP strippers. If not, why even keep up the game? It's not like pirates can already defeat virtually all copy protection mechanisms on the market, even before HDCP ever enters the field.
null
amelius
Looking for a way to show an image over HDMI while my embedded system is booting, and then (seamlessly) switching over to the HDMI output of that system when booting finishes. Any ideas how to accomplish that? In hardware, of course.
myself248
Seems to me like the answer is to get the splashscreen going earlier in your boot process. If you know the display geometry, I suspect you can skip the DDC read and just hardcode the mode and stuff, which should save even more time.
actionfromafar
There are a bunch of HDMI switches with buttons on them, and some with remotes. Doesn't seem too outlandish to rig these buttons or remotes to be controlled by the computer itself.
amelius
Yeah, I've looked into them, but I still need to generate the second image and these switches typically don't provide a seamless transition, so it's not optimal.
pinoy420
[dead]
peterburkimsher
Looking for a way to freeze an HDMI feed so that the current image (a PPT slide) stays up on the projector/TV while edits are made. Any suggestions welcome.
coolhand2120
https://magicmusicvisuals.com/ combined with https://obsproject.com/. And possibly OBS all by itself.
adolph
Nice to see another use for those lanes exposed with M.2. M.2 to OcuLink to a standard PCIE slot/carrier still seems more flexible tho.
example: https://community.frame.work/t/oculink-egpu-works-with-the-d...
tehlike
Coral boards also use m.2
aaronday
[dead]
>Fortunately, those extra PCIe lanes tend to get repurposed as additional M.2 holes.
Or unfortunately, for the unlucky people who didn't do their research, so now their extra M.2 drives are sucking up some of their GPU's PCIe bus.