I need some assistance regarding the compatibility of running an Intel Arc A380 card as a secondary video card for encode-only purposes.
Currently, I am considering the MSI MAG X670E TOMAHAWK WIFI motherboard for my build, which features three x16 PCIe slots with the following configuration: 16/4/2.
My main concern is whether it’s feasible to run the A380 off a PCIe x16 slot with only four lanes, or if I should explore getting a motherboard with PCIe bifurcation support. I don’t really want to shell out for a even more expensive motherboard unless I have to.
If you require any further details about the components in my build to provide more accurate advice, please let me know, and I’ll be happy to provide the specifics.
Here’s the PCPartPicker list for the build: pcpartpicker,com/list/4tRfKp
I appreciate any insights and guidance the Level1Techs community can offer on this matter. Thank you in advance!
I would imagine that an A380 would work fine off of a x4 slot, but I’m not sure. However, I am pretty confident that the XFX Speedster MERC 6950 XT is a 3 slot tall card that would block the x4 slot on the MSI Mag X670E.
The only concern should, I think, be PCIE bandwidth, since the primary GPU needs to send back the frame to the system, and then the system needs to send it to the secondary GPU for compression, and receive back the compressed stream.
In theory, you only need about ~6GB for 3840x2160 24bit 120fps, which is just about right for a Gen 4x4 link. If you plan to do more than that, you may need to consider your resolution and framerate.
Not sure if the Arc drivers need more bandwidth for running the encoder, but it’s about 5.5up and something relatively pretty inconsequential down.
When you get close to the full link speed with your frames stream, it can cause some pretty bad stutter, both in the video and for the host system.
Source: Using a 1030 as a secondary 4k 60hz display and trying to stream and record the screen from it to a 1060; It could not do 60fps, but could do 30, which lines up with uncompressed framebuffer bandwidth, making it the most reasonable explanation to my mind.
I’ve had issues with my A770 + A380 with my AM5 build. Secondary GPU being in charge of stream encoding is basically unusable. Using it as a dedicated ffmpeg encoder has been fine.,
would you kindly explain? I am looking to build a server that can encode & record multiple camera streams to HDD. Is stream encoding different from ffmpeg encoding?
For stream encoding the primary GPU needs to send uncompressed frames to the secondary GPU, which is very bandwidth intensive. For file encoding, that is not the case since a compressed video is sent to the GPU, decoded and reencodedthere, so needing much less bandwidth.
Correct. Game streaming with the setup I attempted is trying to copy frames from the primary gpu to the secondary card. This has significant performance penalties when the primary GPU is already saturated.