Hi,
my PC has a RTX 3080FE.
I want a triple screen setup with QHD monitors for simracing.
The CSV-7300 is the Hub with the best specs I found.
So when I choose Monitors (3 x 2560×1440) with DP 1.2 they dont have DSC…
what refresh rate would be possible? (Tried to calculate it by myself, but struggled)
Hi Gretzer,
Why use the CSV-7300 if the RTX 3080FE has 3 x DisplayPorts 1.4? Assuming you want to do surround video.
DP1.2 can do 32.4Gbps over a cable. = Max 4K120Hz 8bit 444 or 4K120Hz 10bit 420
DP1.4 can do 40Gbps over a cable. = Max 4k120Gz 10Bit 444
Of course depending on your screen if it actually can do those settings.
https://www.club-3d.com/en/technology/13/possible_resolutions/
https://www.club-3d.com/en/technology/8/displayport/
Hi Baak, and thanks for your answer!
Didn’t mention, that i also use Oculus Rift S (occupies one DP) and also a 34 inch ultra wide for other games (what also occupies one DP)… so only one DP left. 🙂
I realized that there are some QHD monitors with DP1.4 so i could also use DSC i think and get higher framerates on my three displays.
So i came to a value of about 95fps than the Bandwith of DP1.4 is reached. Can someone confirm?
Greets
FPS is something different than Hz. FPS is determined by your actual hardware and not the DP . GFX cpu memory it all counts and boosts the FPS. You can produce 400FPS on a 60Hz monitor.
Is there not a maximum of supported displays on a RTX 3080?
Anyways the CSV-7300 supports 3 x 4K at 60Hz as a maximum.
Yeah… well… you are right. But assumed the hardware has infinite power… I want to know which refresh rate is possible limited by bandwith of DP1.4 with the pixelcount of 3xQHD… so ~95Hz?
AFAIK RTX 3080 supports 4 displays. But I will never use more than 4 at the same time, so having 6 of them connected shouldn’t be the problem.
Even if the displays don’t have DSC (they are DisplayPort 1.2), the MST hub should be able to take a DSC input and decompress it for the DisplayPort 1.2 displays.
DP 1.2 is 17.28 Gbps.
DP 1.4 is 25.92 Gbps.
Adding an MST Hub does not increase the number of displays a GPU can support. NVIDIA GPUs are usually limited to 4 displays. AMD GPUs are usually limited to 6 displays.
For the refresh rate calculator, the Resolution is supposed to be width x height, not pixels x displays. To calculate what you want, you have to determine the max data rate for a display (DisplayPort 1.4 with DSC = 25.92 Gbps x 2 compression factor / 3 displays = 17.28 Gbps) which in this case is similar to DisplayPort 1.2. So use the refresh rate calculator to get the max refresh rate for 17.28 Gbps = 174.2 Hz which is very close to what you calculated.
The delay for the CSV 7300 should be small because it doesn’t need an entire frame to do DSC decompression.
Thank you joevt for your input! clarifies some points!
About that the MST is doing the decompression? So are you really sure that I’m fine using Displays which only have DP1.2. Would be really bad if this then would not work!
I know I abused the calculator with my pixels x displays. 😀 I can’t really follow your explanation, but the results are fairly the same…
So the delay is very important for me. If I buy high tier displays with an input lag e.g. of 5ms and the CSV 7300 adds then 20ms… It makes the expensive displays somehow obsolete…
Yes, the MST Hub does DSC decompression. The CSV-7300 product page shows how DSC allows connecting more displays than without DSC but they don’t give bandwidth numbers (they don’t describe the pixel format for the DSC case, and they don’t mention the level of chroma subsampling for either case).
I haven’t tested my MST hubs (not Club 3D) that support DSC with multiple displays yet. I have a Radeon W5700.
