Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Demigod Mac

macrumors 6502a
Original poster
Apr 25, 2008
844
290
Got my 780 from MVC, plugged it in and it's good to go! Card is blazing fast and laughs at anything I throw at it.

I'm having an issue with the Displayport > Mini Displayport adapter though. It doesn't seem to like the EFI boot screen at all. I get sparkly image corruption followed by a heavy rainbow effect if the display remains plugged in after a restart or power up, which doesn't go away if it continues to boot into OS X. If I unplug/replug at that point, black screen. My guess is it's some kind of handshaking issue.

* If I unplug the cable, then boot my Mac, then reconnect the cable, I get perfect video.
* No issues waking up from sleep.
* If I connect the card to my TV via the HDMI port it works perfectly, boot screen, Apple logo and everything. Zero corruption.
* Issue doesn't happen at all on Windows/Bootcamp. There's a little bit rainbow corruption on the initial white screen, but then it goes normal after the boot screen's gone and Windows starts up.
* My display is the original Apple LED 24", mini displayport connector.
* StarTech Displayport Male - Mini Displayport female adapter

I THINK it the adapter is at fault; perhaps it's missing some circuitry needed to display the EFI screen properly? Does anyone with a modded card use a similar adapter that works perfectly?

It's not a massive issue since I rarely ever restart or shut down my Mac, but I'd like to find a solution if there is one.

WNebdsW.jpg

Oh yeah, one other little scare - I tested the card under load and soon heard a loud continuous BEEP... panicked for a second thinking it was my Mac or the card (forgetting for a second that neither has an internal speaker) then I realized it was my 2 year old UPS battery screaming. :) Changed the Mac to one of the regular power ports and the sound stopped.

Other than that, card works great and performs brilliantly.
Very happy with it and I'd recommend MVC's mod service to anyone interested.
 
Last edited:
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
I really don't like those adapters. If it were me, I'd go with one of these:

http://www.monoprice.com/Search?keyword=mdp+to+display+port

I used one a couple of years ago, but in reverse of yours. I had a flashed ATI card with an MDP on it and went to my HP IPS display with Display Port. The cable worked great.

IMHO, MonoPrice makes great stuff, and it's so reasonably priced. They have become my exclusive cable and adapter supplier.

Oh, and ya, my MVC flashed Gigabyte GTX780 (Display Port to Display Port) is working great!

Lou
 
Sounds like a bad adapter.

Each card is tested on a 24" & 27" ACD , on a Startech DP to MDP like the one we ship with.

Out if a few hundred adapters shipped we have had a couple wonky ones.

Send a message through EBay via the transaction page for 780 and mention this post. We'll send another one but please ship back bad one, we'll return for replacement.
 
Actually the adapter's mine, from Amazon. Is this the same one you supply with modded cards?

http://www.amazon.com/gp/product/B003N3DTKY/

(your shipment didn't include an adapter, no biggie though as I didn't mention what kind of display I have )

If that's the case I can probably order a replacement from Amazon and then send the defective one back.

flowrider,
Unfortunately I don't think Monoprice has what I need... My Apple display has a male mini displayport connector; it needs a female mini displayport + male displayport adapter.
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
.flowrider,
Unfortunately I don't think Monoprice has what I need... My Apple display has a male mini displayport connector; it needs a female mini displayport + male displayport adapter.

Sorry - it appears they don't. They have it going the other way. but not what you need.

Lou
 
Last edited:
Yeah, we don't send any cables with mod service unless you order them at same time. It would make sense that most people getting mod done have already been using the card and just want the boot screens, working PCI cards section in System Profiler and PCIE 2.0 support in both OSX and Windows. We use Startech brand from Newegg.
 
Yeah, we don't send any cables with mod service unless you order them at same time. It would make sense that most people getting mod done have already been using the card and just want the boot screens, working PCI cards section in System Profiler and PCIE 2.0 support in both OSX and Windows. We use Startech brand from Newegg.

MacVidCards, can you please check your private messages
 
NewEgg has this one, which looks to be the same as Amazon:
http://www.newegg.com/Product/Product.aspx?Item=N82E16812200691

I found alternate brands for the same adapter:
http://www.newegg.com/Product/Product.aspx?Item=9SIA2970S23273
http://www.newegg.com/Product/Product.aspx?Item=9SIA2JX1053462

I ordered a replacement from Amazon; it should arrive tomorrow.

If that one fails, I'll try a different brand.

If the other brand has the same issue, I guess we can chalk it up to some protocol issue....
 
NewEgg has this one, which looks to be the same as Amazon:
http://www.newegg.com/Product/Product.aspx?Item=N82E16812200691

I found alternate brands for the same adapter:
http://www.newegg.com/Product/Product.aspx?Item=9SIA2970S23273
http://www.newegg.com/Product/Product.aspx?Item=9SIA2JX1053462

I ordered a replacement from Amazon; it should arrive tomorrow.

If that one fails, I'll try a different brand.

If the other brand has the same issue, I guess we can chalk it up to some protocol issue....

I think it's probably a faulty adapter. I have one like it for my GTX 780 macvid modded. Works fine with it under bootcamp and OSX.
I hope the next one will be good...
 
I hope so. Again it's no biggie, I just have to remember to unplug/replug the cable every time I reboot.

Does anyone else here use the original 24" Apple LED Cinema display (2008 - MB382LL/A) with a Displayport>MiniDisplayport adapter?
 
Yeah, we don't send any cables with mod service unless you order them at same time. It would make sense that most people getting mod done have already been using the card and just want the boot screens, working PCI cards section in System Profiler and PCIE 2.0 support in both OSX and Windows. We use Startech brand from Newegg.

MacVidCards, can you please check your pm 's.
 
Unfortunately it looks like the replacement has the exact same problem.

I'm starting to think it might be an issue with my monitor, or at least how my monitor and this particular adapter handshake at startup.

I tried this reverse combination:

Mac Pro >> DP-to-mDP adapter >> mDP-to-HDMI adapter >> TV

... got a perfect boot screen.

Just ordered one of the alternatives from Newegg, though the shipping time will be quite long.
 
Last edited:
i think so,Just ordered one of the alternatives from Newegg, though the shipping time will be quite long.
1cA3M92
 
We use the STarTech brand in the first Newegg link.

I test each card on 24" and 27" MDP Apple Displays

I have only seen an issue with one or 2 adapters.

It is possible that your display has a unique issue.

I imagine if it needed a firmware update, it would prompt you. I recall that the 27" had an Audio issue that required an update.

If you have used 2 separate adapters like the Startech one, the issue isn't the adapter. If it is a different brand, it might be the brand.

But I have been using that same adapter and have sent out more than 100 of them, and only 1 came back. They were same ones we used on 570 and some 5770 and 5870 cards. We have also included them with 680, 770 and some other cards. Nowhere else has the issue come up.

Do have a look on the back of the card where the DisplayPort connector has it's pins poke through. There are some tiny transistors and capacitors, etc. If even one of these has a broken leg or appears missing, that could also cause this.
 
We use the STarTech brand in the first Newegg link.

I test each card on 24" and 27" MDP Apple Displays

I have only seen an issue with one or 2 adapters.

It is possible that your display has a unique issue.

I imagine if it needed a firmware update, it would prompt you. I recall that the 27" had an Audio issue that required an update.

If you have used 2 separate adapters like the Startech one, the issue isn't the adapter. If it is a different brand, it might be the brand.

But I have been using that same adapter and have sent out more than 100 of them, and only 1 came back. They were same ones we used on 570 and some 5770 and 5870 cards. We have also included them with 680, 770 and some other cards. Nowhere else has the issue come up.

Do have a look on the back of the card where the DisplayPort connector has it's pins poke through. There are some tiny transistors and capacitors, etc. If even one of these has a broken leg or appears missing, that could also cause this.
MacVidCards, I've sent you pm's and a few emails. Can you please get back to me.
 
Back of the card looks good... Weird. I wonder why this only affects the boot screen and everything else is flawless. What does the EFI boot screen do differently than standard OS X and Windows? Or maybe it's some kind of power-on handshaking issue. Sure wish I had another mDP/Thunderbolt display to test.

Well, I guess I'll find out more when I get the other brand adapter in, which should be in about 2 weeks.

Could of course get one of those Kanex or Belkin HDMI-to-mDP boxes but, probably not worth $60+ just to avoid having to unplug/replug every time I reboot, which is usually twice a week. :)
 
Update:

Got the cable from a different manufacturer - same problem! I guess it's an issue with my monitor, then (original 2008, Apple LED 24").

So now my OS X boot routine is:

1. Issue reboot command
2. Unplug video cable
3. Wait for Mac to chime
4. Reconnect video cable
5. Monitor lights up at the OS X login screen​

Again, no biggie, since I don't reboot very often at all, and sleep/wake still works perfectly. And rebooting into Windows works without any problems. Is the 780 GTX worth it? Definitely.

I'm just perplexed as to what's going wrong when the card and monitor handshake over Displayport-MiniDisplayport adapter and how/if the boot screen video signal is any different from the regular video signal that the Mac outputs.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.