system can't boot with displayport MST on.

[Zurvv]

I'm have the rampage IV and 3 asus Titan's in SLI.
My monitor (Sharp pn-k321 - 32" 4k monitor) uses Display MST (multi stream transport).
If I turn this option on it works fine, rebooting is also fine. But a cold boot POST will not work. I have to power up a few time and get into normal/safe mode boot/bios to get it up again.

(to get 60hz at 4k - I need MST)

My guess is it needs a bios updated to address this. I have yet to try 4004 - which i'll do tomorrow, but I don't see release notes talking about MST.

full system specs:
Asus Rampage IV Extreme, i7-3630k (6 cores) 4.7ghz (water cooled)
Mushkin RedLine ram 1866 DDR3 (32gigs Quad channel), Seasonic 1250 Watt PSU
OCZ 128 Vector SSD (system drive), OCZ 512 Vector SSD x2 (raid 0), Seagate 3TB HD
Nvidia Titan 3 way SLI (watercooled), 32" Sharp UltraHD pn-k321 (3840x2160)
Logitech G19 / G9, wired 360 controller
audio: Audiolab M-DAC -> Rega Brio-R (AMP) -> Denon AH-D5000 (headphones) or PSB imagine mini (speakers)

[HiVizMan]

WOW nice system mate. Sorry but here I can not help you as I only have the motherboard and the CPU none of the rest. Will bump this upstairs though.

[Zurvv]

HiVizMan wrote:
WOW nice system mate. Sorry but here I can not help you as I only have the motherboard and the CPU none of the rest. Will bump this upstairs though.

Thanks!

I have a month before it becomes a big problem. the way sharp does 60hz on a 4k panel is they break the screen into 2 screens.
(I can do full rez at 30hz with one screen - but 30hz sucks for gaming). That is why I'd use DP in MST mode.
Nvidia does not span with only 2 screens - but this is changing, also thanks to this screen >.<
Nvidia should make this screen useful to gamers (ie, spanning 2 screens via MST to make one logical one) in driver R325

I'm sure there are other SLI Titan owners with this screen and a rampage IV (it rocks!) 🙂


again thanks

[Zurvv]

Any update? the ASUS PQ321Q is the same monitor as the sharp than i'm using (just cheap by like $1000 -- ugh!) - so more support issues might come up about this.

in normal mode it works fine... and MTS is fine if I switch to it while i'm already in windows - but the computer won't post if the monitor is set to MTS (unplugging the DP cable or changing the monitor back to SST will make it bootable again).

I didn't upgrade to the latest bios because of the fan issue.

Please advice.

thanks!

[HK-47]

Are you sure your cables comply with VESA standards? I few around these parts have found cables that do not follow VESA displayport 1.2 specs and back feed power on pin 20 of the cables. Pin 20 in basically 3.3v volts to power a branch device over a displayport cable. If Pin 20 is connected it could be back feeding 3.3v into your GPU and motherboard. You can check this easily with a multi-meter. Measure your power cables on the motherboard power cable to ground with the system unplugged from the wall (Should measure no voltage). Another test, you can try and boot with the monitor unplugged and see it will boot without issues.

[HiVizMan]

I will bump it up stairs and see if there is anyone who can help.

[Zurvv]

thank you sir!

[X-ROG]

Firstly, have to tried different cables and the other cards to see if it's a physical problem?

[Nodens]

I would also follow HK-47's advice and test for pin 20 leakage. There are a lot of cables that do this and it can not only cause what you describe but physical damage to your hardware as well.

[Zurvv]

http://youtu.be/Wa-DRVqPJRo?t=24m23s




these guys are testing the asus 4k monitor (which is the same as the sharp) and they too can't POST in MST mode. They are also using a Asus board and a titan.

it isn't the cable - I tried 3. MST works - the system just won't POST when the monitor is in that mode.