Monitors blink on/off after I daisy chain my 3 NEW Dell U2415's!!! Help!

[Keystone4132]

Just bought 3 new Dell U2415's for their daisy chaining capability. When I connect them as per directions, they do indeed daisy chain, but almost immediately they begin blinking to black screen and on again, like lights on a Christmas tree (only slower).


My setup:

Mobo: Asus P8P67
CPU: i5 2500K (not overclocked)
GPU: Radeon HD 6850
SSD: Samsung 850

The AMD Radeon HD 6850 specs claim to support:
◦DisplayPort 1.2
◦Max resolution: 2560x1600 per display
◦Multi-Stream Transport
◦21.6 Gbps bandwidth
◦High bit-rate audio

My monitor cables are DP1.2 and brand new.

At first, all I could get the monitors to do was mirror each other. 3 expensive monitors showing the same thing doesn't work for me. After 3 hours with Dell phone support they finally told me no mas without solving the issue, because the monitors were not connected to a Dell PC. $@#!$%%@!

So, thinking it was a software/driver issue, I disconnected all my drives except the SSD and did a fresh Windows 7 install from DVD, and then downloaded and installed all of the Windows updates. Installed Dell monitor driver off of DVD that came with monitors. Updated Bios and latest chipset, GPU drivers and AMD Catalyst Control. Nothing else is on the SSD besides Win 7, Windows Security Essentials, Malwarebytes. No other storage drives.

I reset all of the monitors to factory settings and then Enabled DP1.2 on the monitors #1 & #2. Monitor #3 was already Disabled. Voila...Windows recognized 3 independent monitors and I was very happy. Until they started to blink on and off after a few minutes. #$%!@#@#

Windows is fresh, bios and drivers are up to date. This is driving me crazy.


So, anyone have some ideas on what I am doing wrong?

Thanks!

 

[ffg7]

does it happen with just 2 monitors connected not disabled? what is the rated wattage output of your psu?

 

[Keystone4132]

does it happen with just 2 monitors connected not disabled? what is the rated wattage output of your psu?

ffg7, thank you for your response. My PSU is a Corsair HX650W....650 watts.

I disconnected Monitor #3 from #2 and enabled Monitor #1. After about 2 minutes, both monitors began to blink.

Any other thoughts?

 

[ffg7]

try it with just 1 monitor as I think it is a videocard issue. know anybody who has a similar system especially the videocard with displayport?

 

[Keystone4132]

try it with just 1 monitor as I think it is a videocard issue. know anybody who has a similar system especially the videocard with displayport?

Thanks again for responding.

It works fine as a single monitor setup, no blinking.

When I disable DP1.2 on Monitor #1, all three monitors mirror each other, but they don't blink. When I enable #1, I get a full extended desktop across all three, but they blink.

My GPU is 4 years old but supposedly geared to eyefinity/multidisplay. I would be interested to hear what setup has worked for folks who daisy chain the U2415s. I am open to upgrades.

 

[ffg7]

I would say it is your videocard that is causing this problem. know anybody who has a newer videocard with displayport that might let you borrow it to see what happens?

 

[Keystone4132]

I would say it is your videocard that is causing this problem. know anybody who has a newer videocard with displayport that might let you borrow it to see what happens?

You are probably right, although this GPU is listed on www.displayport.org/products-database/ as compatible with DP1.2.

Do you think the card is overloading, causing the screens to blink?

 

[ffg7]

I think so which is why to try to borrow a newer card to see if still a problem or not.

 

[Keystone4132]

I think so which is why to try to borrow a newer card to see if still a problem or not.

Thanks, makes sense. I won't be able to borrow one, will likely have to buy new one and then return it, if I get the same result. Any suggestions on an AMD GPU? I understand Nvidia doesn't play nice with daisy chaining.

I have been on the phone with Dell for the last hour, getting bounced around all over the place to no avail.

 

[ffg7]

talk to your local computer store to see what they recommend for a videocard & maybe take at least 2 of those dells with you to try on 1 of their systems unless you take yours before buying a new card. read this link. http://www.tomshardware.com/forum/id-2930109/dell-u2415-monitors-card.html

 

[Keystone4132]

Just installed a new Radeon R7-360 and it works like a charm...at least for the hour since I installed it. Thanks again for the quick responses and good advice.

 

[ffg7]

no problem.

 

[Keystone4132]

I spoke too soon. My black screen blinking has returned.

On Friday, I decided to do a significant system upgrade in addition to the GPU. I purchased and installed:

CPU: Intel Core i7 4790K
MoBo: Asus Z97-A
OS: Win 7 Pro
RAM: 16GB (2x8GB) Corsair Vengeance DDR3 1600

I retained:

PSU: Corsair HX650w
CPU cooler: Cooler Blaster 212+

My 3 Dell U2415s are all REV A02, purchased 1 week ago. DP1.2 cable running from GPU to Monitor #1. DP1.2 cables connecting 1 to 2 and 2 to 3.

So...essentially I now have a new and reasonable capable system.

The good news is that the rate at which they black screen blink has decreased from once every 60 seconds or so, to once every hour or so. I did notice that when I was in the midst of copying 12 gig of files from one of my HDDs to one of my SSDs the pace of blinking increased significantly, similar to what I saw before upgrading components.

How could this increased load be impacting MST? Any ideas?

 

[Keystone4132]

no problem.

I left off the GPU upgrade purchased:

Sapphire Radeon R7 380

 

[ffg7]

what is the MST? do you have or can borrow a different psu to see if still have that issue?

 

[Keystone4132]

what is the MST? do you have or can borrow a different psu to see if still have that issue?

MST, multi-stream transport, displayport. Probably not the right terminology. I was trying to ask if increasing the number of tasks the cpu/drives performs might be the cause of the black screen blinking. I answered my own question because as I sit here typing out this response with just a browser open, all 3 screens have gone black twice.

I guess I can go buy a new PSU but the Corsair HX650w has almost double the power that I calculated I needed from: http://powersupplycalculator.net/.

Really very frustrating.

What causes a screen to blink?

 

[ffg7]

where did the display port cables come from? try switching the cables around to see if maybe a bad cable is doing this.