Re: [求助] EW3270U 10bit設定疑問

[vwvwbg (VwVwBg)]

在幾個月後

論壇的文章總算看到AMD官方的人員出來回覆了

https://community.amd.com/message/2904758

以下原文
反正就等吧

Fixed in 19.Q2 driver available on May 8th.


Root cause:

Whenever a monitor has a CEA extension block with a CEA SVD for
3840x2160@60Hz the current and some previous drivers (except
18.Q1.1 and older) use 594MHz pixel clock and for that we do not
have enough bandwidth to do 10bpc, that's why the color depth
jumps back to 8bpc. Obviously the monitors without the above
mentioned CEA extension block did not have any issues reporting
10bpc/RGB444/4K@60Hz


CEA extension block with a CEA SVD is mostly used for digital TVs
 & HDMI connections


Interim Workaround:

Emulate the EDID of your monitor with a Bit Rate of 8.1 GHz, that
might work for some monitors. If you need assistance with that, PM me.



Exception:

BenQ EW3270 still reports 594MHz, which seems to be a monitor issue
(still under investigation). However changing the Bit Rate to 8.1GHz
(HBR3) resolves the issue.


--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 122.116.161.14
※ 文章網址: https://www.ptt.cc/bbs/LCD/M.1552719523.A.756.html
※ 編輯: vwvwbg (122.116.161.14), 03/16/2019 14:59:23
→ seiya2000: 英文看不慬
→ AKSN74: 簡單來說，AMD的驅動由於EW3270回報的頻寬數值錯誤導致驅
→ AKSN74: 動沒辦法讓這台螢幕調整成RGB444 10bit
→ AKSN74: AMD會在Q2開始的驅動版本修掉這個問題
→ AKSN74: 更正 沒辦法調整成RGB444 10bit是驅動本身的問題 但EW3270
→ AKSN74: 由於韌體回傳錯誤數值導致這台螢幕依舊無法開到10bit
→ AKSN74: 但如果強制調整頻寬的話則問題解決，AMD還在研究問題在哪
AMD員工有貼另外兩張圖解釋
https://goo.gl/G32G2x
https://goo.gl/FPUzKH

用了不同的標準
造成螢幕達成10bit RGB444所需要的頻寬不同

順帶一提DP1.2的頻寬是21.6Gbit/s

不過我不是很懂得是
DP1.4給的頻寬應該是高過這個值的
而卡線螢幕都有DP1.4的情況下卻沒有辦法
※ 編輯: vwvwbg (122.116.161.14), 03/16/2019 18:01:17
→ quamtum: 就一個是標準另一個是reduced blanking,後者需求較小
→ quamtum: 在1920x1080也有兩種模式
推 popbitch: 螢幕有CEA extension block，驅動就會用594Mhz的頻寬
→ popbitch: 這個頻寬不足以用10 bit，所以會降到8 bit
→ popbitch: 沒有CEA extension block的螢幕就能使用10 bit
→ popbitch: CEA extension block常使用在數位電視和HDMI裝置
→ awangya: 另一個方法就是螢幕送BENQ安裝新韌體，這次送更新為V106
→ awangya: 版已可正常顯示10Bit
推 gpee: 螢幕版本要去哪裡看啊
推 popbitch: 後面提到將螢幕的EDID模擬成8.1Ghz可暫時解決問題
→ popbitch: 但BenQ EW3270是例外
→ popbitch: 所以還是要螢幕這邊更新韌體才能解決
→ vwvwbg: 更新完是不是連同之前WINDOWS HDR的問題也修了?
→ vwvwbg: 話說應該是EW3270改成8.1Ghz可以解決問題吧
推 s9209122222: 我benq ew277hdr的edid也怪怪，少了vsd那項