Eve Spectrum Prototype Tester | Marat Tanalin

I’m pretty curious, is that for all modes, or just for 4K?

Many old graphics chips in old graphics cards only can do MST-based (dual-channel) 4K30 to achieve 4K60. There’s pretty much two ways to achieve 4K 60 Hz – and older GPUs end up needing to create a dual-channel over the same cable, to create a pair of 4K30 bandwidth links to do 4K60.

It’s supposed to be transparent to users but older GPU chips capable of DisplayPort 1.2 (even when you use newer DisplayPort cables), sometimes end up needing to use MST (Multi-Stream Transport) protocol to achieve 60 Hz on a 4K display instead of 30 Hz. Newer DisplayPort standards (1.3 and newer) can do 4K 60+ with single stream.

So basically the two totally different different ways for a DisplayPort source to do 4K 60+ Hz. And it’s possible Eve doesn’t support one of the two (MST-based 4K 60 from older GPUs) – maybe something to ask Eve / Lehui. Or perhaps some DisplayPort identification is not being relayed somehow by your particular GPU – I’ve seen DisplayPort 1.3 GPUs advertise themselves as DisplayPort 1.2 protocol devices, and same for monitors. Something to debug, I presume?

This might not be the problem, just maybe an unturned stone to check.

Also:

In Windows 10, I noticed ToastyX CRU can also be used to bypass NVIDIA GPU scaling – try testing creating pixel perfect resolutions by creating the custom resolutions in ToastyX than in NVIDIA Control Panel. This is also the recommended solution for Intel GPUs and AMD GPUs too as well;

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Just 4K, like if bandwidth was not enough — just like in case of HDMI 1.x where bandwidth is actually not enough. At FHD, I enjoy 144 Hz via DP and 120 Hz via HDMI 1.x.

The same DP cable (each of both cables I tried — v1.4 by Hama and v1.2 by VCOM) provides 4K@60Hz with Dell P2415Q.

Dell P2415Q (2015) is an SST monitor unlike the previous Dell model UP2414Q (2014). This is confirmed in particular, by that GPU scaling works which is known to be impossible on first-generation 4K monitors where MST was used to overcome temporary monitor-hardware limitations.

MST can be used in Dell P2415Q for daisy chaining — connecting another monitor to DP output of P2415Q which (the P2415Q monitor) is then the first and only monitor connected directly to computer as the video source.

That’s interesting, thanks. Though I already found a way to switch resolution without silently switching to GPU scaling: just by selecting the needed resolution not via the main W10’s display settings window, but via the classic “List All Modes” window available via a button in the “Advanced display settings” window.

While we’re at it, does CRU edit the monitor EDID (that I wouldn’t like to take risk of) or does it function somehow else?

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No. It is just EDID overrides in the Windows registry. The Windows registry has a mechanism to EDID-override the monitor, and ToastyX edits that. You can do things NVIDIA doesn’t let you do, like edit FreeSync ranges, test extreme overclocked refresh rates (e.g. 500 Hz refresh rates), large vertical totals, etc.

You can use reset-all.exe to undo everything ToastyX has ever done, so there’s an escape hatch included.

P.S. ToastyX is a popular utility in the Blur Busters Discussion Forums

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Pixel-perfect (integer) scaling —
testing with a non-computer video source:
SNES Mini game console (1280×720) ✔️

SNES Mini (Super Nintendo Classic) is the official retro game console from Nintendo that replicates (with emulation) the most advanced 16-bit console — Super Nintendo.

SNES Mini outputs 1280×720 (HD) via HDMI and has a pixel-perfect mode, but previously edges of pixels inevitably got blurry anyway on all 4K monitors and TVs due to blurry HD→4K scaling by the display itself.

Now with the Eve Spectrum 4K monitor and its “Pixel perfect” upscaling mode, we finally get perfectly sharp image with zero blur when using SNES Mini. And as long as the game does not need aspect-ratio correction and looks fine with square pixels (e.g. “Super Mario World” or “BlackThorne”), the resulting scaled image is also free of horizontal distortion / pixel shimmering. (SNES Mini’s 1280×720 output resolution is too low for pixel-perfect aspect-ratio correction with integer scales used both vertically and horizontally like e.g. bsnes-mt emulator does.)

720×480 instead of 1280×720 via HDMI port #2 [NEW 2021-07-21]

For some reason, SNES Mini output is displayed as 720×480 when the game console is connected to Eve Spectrum via the monitor’s HDMI port #2 instead of #1. So instead of being pixel-perfectly scaled to 4K, the image is blurry and smaller than it should be:

The photos below are taken with SNES Mini connected to Eve Spectrum via HDMI port #1 which is free of this issue.

Stuck at “Pixel perfect” at some moment

Below are my photos of SNES Mini user interface and some games. My original intent was to provide photos of the same images in pixel-perfect mode and regular blurry scaling mode of the monitor side by side, just like I did previously with 640×480 PC games. But at some moment Eve Spectrum stuck at “Pixel perfect” mode and made the “Aspect Ratio” option in monitor settings disabled/inactive at 1280×720 for unknown reason:

And even switching the “Aspect Ratio” option to “Maintain aspect ratio” at 4K where the option was available, had no effect at 1280×720. So I was unable to take blurry versions of photos taken after that moment and they are only presented in “Pixel perfect” mode as a result.

Hopefully the issue with the “Aspect Ratio” option available inconsistently will be fixed in a new firmware.

UPDATE (2021-07-21): Looks like the “Aspect Ratio” option gets disabled when “Low-latency mode” is enabled which also gets disabled automatically when “Adaptive-Sync” is enabled. Thanks Grant (@Lore_Wonder) for clarification.

As with the previous photo set, view full-size photos (not resized by web browser) to see a more detailed image.

SNES Mini user interface

Just in case, the “gear” icon is scaled unevenly by SNES Mini itself when the menu item is current. The monitor’s pixel-perfect scaling is 100% uniform.

Super Mario World

Classic Nintendo game and character.

BlackThorne (BlackHawk)

The SNES version of this game has exactly the same graphics as its DOS version, but lacks original music. This game does not come with SNES Mini by default.

Donkey Kong Country

This game actually needs aspect-ratio correction for proper object proportions, so the image is slightly narrower horizontally than intended, but I still decided to provide a photo of a nostalgic scene in pixel-perfect mode.

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I love retro gaming! Makes me want to get some of my old consoles out, but i’ve still got a few NextGen games I would like to complete.

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More about pixel-perfect (integer) scaling via HDMI

Additional empirical data collected when connecting via HDMI 1.x again:

  • When booting (loading) computer, the monitor menu displays “1280x1024@60Hz” as the current mode. But in fact, the resulting image looks like it’s first upscaled with blur to an intermediate resolution (probably exactly the 1280x1024 displayed in the monitor menu), then that already blurry image is finally upscaled with no blur with 2×2 square pixels.

    This is probably due to lack of EDID support for 720×400@70Hz, 640×400@70Hz, or 640×480@75Hz modes potentially used by non-UEFI BIOSes (“Award Modular BIOS v6.00PG” in my case) during boot. Black screen via DP during boot has probably the same root, while HDMI controller probably performs some transparent conversion of modes missing in EDID.

  • The interlaced 1080i mode is not scaled and is displayed as “1920x1078” in the monitor menu under Linux only. In Windows 10 and 7, and with the Panasonic GF5 photocamera as the video source, interlaced 1080i is displayed in the monitor menu as “1920x1080” and pixel-perfect scaling does work.

  • At resolutions 1440×900, 720×480, etc., the image is centered instead of scaling, only in the “Pixel perfect” scaling mode of the monitor. In the regular blurry “Maintain aspect ratio” scaling mode, the image is scaled at the same resolutions.

    So a possible reason of centering instead of scaling in the “Pixel perfect” mode is that specific scales (scaling ratios) in the “Pixel perfect” monitor mode are hard-coded into firmware instead of being calculated dynamically and are just wrongly set to 1.0 for corresponding resolutions.

  • The Windows-specific issue that makes it impossible to output 640×480 via HDMI to the monitor directly without prior forced GPU scaling to 800×600, happens in both Windows 10 and Windows 7.

I updated my first report about pixel-perfect (integer) scaling here accordingly, and added “NEW 2021-07-01” mark where reasonable.

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Pixel-perfect (integer) scaling —
testing with a non-computer video source:
Panasonic GF5 photocamera (1080i, 480p, 576p)

Tested Eve Spectrum with the Panasonic GF5 (2012, Micro 4/3, MiniHDMI) photocamera as the video source:

  • Works fine with no general issues compared with PC as the video source.

  • The photocamera supports three output modes:

    • 1920×1080i@60Hz (interlaced);
    • 720×480@60Hz (corresponds to the NTSC standard);
    • 720×576@50Hz (corresponds to the PAL standard).

    Just like with PC, pixel-perfect scaling:

    • does work in the 1080i mode (“1920x1080@60Hz” is displayed in the monitor menu);
    • does not work (centered instead) in 720×480@60Hz and 720×576@50Hz modes.
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DisplayPort-to-HDMI-2.0 adapter — no luck

Bought a DP-to-HDMI-2.0 adapter — Dell 492-BBXU officially capable of 4K@60Hz. Nothing changed.

  • Same 30 Hz as the maximum refresh rate at 4K.

  • Same black screen during boot.

  • The maximum refresh rate available at FHD is 120 Hz like via HDMI 1.x instead of 144 Hz available via direct DP connection.

The DP end is connected to the computer (which has a DP port capable of 4K@60Hz), the HDMI end is connected to the monitor (which has an HDMI 2.x port capable of 4K@60Hz too).

But at least there is now more clarity about a possible reason of 30 Hz issue

I’m starting to suspect there is something wrong in the way the monitor reports supported graphic modes to the video source.

If Eve Spectrum did not support the part of the DP standard that my graphics card GTX 650 Ti Boost uses for encoding/transmitting data via DP, this would unlikely apply to the DP-to-HDMI scenario given that in this case the monitor thinks it’s HDMI anyway and does not know (or does it somehow?) it’s converted from DP.

So the most probable reason of the 30 Hz limit at 4K is that the monitor reports (regardless of via HDMI or via DP) the list of supported graphic modes in a way that makes my GPU think that the monitor’s maximum refresh rate at 4K is 30 Hz.

E.g. 60 Hz and higher rates for 4K resolution are probably reported in a different way that older GPUs don’t understand regardless of whether via HDMI or via DP. So the issue is probably more fundamental than just a specific-interface-level (HDMI/DP) incompatibility.

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you know a man is serious about integer scaling when the words ‘integer’ and ‘scaling’ make up a solid 10% of his introduction post :rofl:

i don’t have anything useful to add, i just wanted to say this is all really cool! :+1:

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Yeah, integer scaling is the main/only feature I’m interested in regarding Eve Spectrum, and the thing I investigate and track for years since purchased a 4K monitor in 2015, and the reason why I suggested myself and was then invited as a community tester of Eve Spectrum in the first place. Nice to see another one interested in the feature too. :handshake:

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HDMI ports #1 and #2: functionally different?

There is apparently a weird issue with HDMI port #2 of Eve Spectrum:

  • SNES Mini has a fixed output resolution of 1280×720 (HD). But when connected via HDMI port #2, it’s displayed as 720×480 instead — both in terms of image size and the current video mode displayed in the monitor menu/OSD. The issue does not reproduce when using HDMI port #1 — SNES Mini output is displayed properly as 1280×720.

  • In Ubuntu 18.10 (Linux), the maximum resolution available via HDMI port #2 is 960×540 at 60 Hz. In pixel-perfect mode, it was displayed centered without scaling. The issue does not reproduce when using HDMI port #1 — 3840×2160 is the maximum available resolution as expected.

Hopefully a firmware-level issue that could be fixed.

Somewhat good news is that 960×540 is not in the monitor’s EDID, yet it was displayed fine by the monitor. 960x540@60Hz was the current video mode explicitly displayed in the monitor menu/OSD. So it’s apparently technically possible for the monitor to display modes missing in EDID.

Sort of bad news is that 960×540 was displayed without scaling, so looks like specific integer scales for all supported resolutions are hard-coded instead of being calculated dynamically for any input resolution whatever it is.

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The snes mini will output 720x480 or 1280x720. Depends on the EDID; you can mess with this using an EDID minder e.g. DVI-EDID DVI-to-DVI DDC/EDID Emulator - ConnectPRO

Sounds like there are a few CEA/CVT timing compliance issues.

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