Custom Resolution Utility (CRU)

[ToastyX]

(12-23-2015 12:31 AM)zamar19 Wrote:  Its interesting, V4900 only spec'd at max 2560x1600@60Hz per port (with 2 DP1.2 and 1 Dual DVI), but it runs 4K@30 easily on 1 port and 1080P@60Hz on another with no extra fan speed. How do I check its actual resolution limits? Or the max Pixel Clock is the only limit that matters for any card, and everything else in resolution spec is flexible? Do they specify in spec max total pixel clock for all ports of a given GPU running monitors simultaneously, or how the max spec works?

The pixel clock is what matters. The maximum pixel clock is separate for each port. Single-link DVI is normally 165 MHz, and dual-link DVI is normally 330 MHz. HDMI varies depending on the hardware. I don't know about FirePro cards, but Radeon 7000-series and newer R9-series cards support up to 297 MHz with HDMI, although using a passive DisplayPort-HDMI adapter is limited to 165 MHz for some reason. The limits are implemented in the driver, so the pixel clock patch allows you to bypass these limits and go as far as the hardware can handle.

(12-23-2015 12:31 AM)zamar19 Wrote:  One problem I've is it shows 4:2:2 chroma at 4K on test images like this one, despite the monitor is 4:4:4 capable. At lower resolutions it's scaling desktop, so the test results are inconclusive. Do you think its caused by current setup bandwidth limit?

Is that happening with the pixel format set to YCbCr 4:4:4 in the FirePro control panel? What about RGB 4:4:4?

If YCbCr 4:4:4 is not available as an option, you might need a custom extension block, or you can just import this file: hdmi-audio.dat

If you add an HDMI support data block in the extension block, it will automatically include YCbCr 4:4:4 by default, and you can also enable 30-bit color (10 bpc).

You might have to manually add some resolutions back in when using a custom extension block. I hope to add support for reading default extension blocks in CRU 1.3.

(12-23-2015 12:31 AM)zamar19 Wrote:  Another issue is it only shows 8bit color at any resolution, but its likely because AMD didn't implement yet 10-bit pixel output support in latest Win 10 FirePro drivers as per Release Notes, unless you can suggest some beta driver? The 10-bit option is available in FirePro CP, but it results in black screen upon reboot.

I don't know how FirePro handles 10-bit color with HDMI. With Radeon cards, the color depth can be set to "10 bpc" in the "Digital Flat-Panel" properties if it's enabled in the HDMI support data block.

(12-23-2015 12:31 AM)zamar19 Wrote:  Btw, this forum Quote feature doesn't work for me in latest FF43.

That's weird. I'm not seeing that with the latest FireFox.