Upgraded to High Sierra - Can't use 2 monitors anymore

[NealF]

Hi,

I've got a 2010 Mac Pro. Had an old samsung syncmaster 204t hooked up to it and a Dell S 2415H hooked up to the DVI port via an adapter going into the VGA port on the Dell.

All was fine in El Capitan. Now I switched to High Sierra and I can't run 2 monitors anymore.
Bought a VGA to HDMI adaptor to try going into the Dell's HDMI port. No go.

I googled it and apparently this is a problem with a lot of folks.
Any ideas on how to get these two going? Or do I just have to go back to El Capitan?

This is my graphics card, if it makes any difference. AMD Radeon HD 7950 3072 MB graphics.
Thanks.

[mikehalloran]

Maybe. Need to know more info. How long ago did you update? What build of 10.13? Is this the OE graphics card? If not, is one available? Is your boot drive an SSD? How do you have your boot drive backed up?

The 10.13.4 update affected graphics but only those using 3rd party solutions such as USB and eGPU — you’re doing neither. I’m trying to determine if it’s High Sierra in general or 10.13.4 only.

[NealF]

I updated about 2 days ago. It's version 10.13.4.

Not sure what an OE graphics card is. My boot drive is an ssd. I back everything up to an external drive via time machine.

[dix]

I didn't lose multi-monitor capability when I tried Sierra and High Sierra, but doing so clearly slowed down the graphics on my MP so I retreated to El Capitan. With MIDI heavy projects, where there's a lot of data displayed in the SE, DP grinds to a near standstill when using Sierra or HS, but not EC. I have to conclude that El Cap is much happier with my card.

So it's either El Cap or a new graphics card for me - and you possibly. However, I can see no real advantage HS has over EC, so it's fine for now.

[mikehalloran]

I updated about 2 days ago. It's version 10.13.4.

Not sure what an OE graphics card is...

Probably a Radeon HD 5770 on this Mac. It supports up to 3 dsplays. You can run two of these.

https://everymac.com/systems/apple/mac_ ... specs.html

[dix]

The OP says he has a AMD Radeon HD 7950 so not Original Equiptment maybe. The Radeon 5770 is what I have and it's not a such good monitor for High Sierra as I mention above.

[mikehalloran]

A non-Apple 7950 may not work properly under 10.13.4.

Did you see a firmware update when you installed 10.13.4? You should have. If you have a non-Apple Radeon HD 7950, you might not.

The easiest solution may be to find a 5770 system pull and install it. Then re-run the installer to ensure that the firmware upgrade runs correctly. According to a few sources, you should then be able to reinstall your 7950 and it may work.

What’s weird is that it half-works.

[mikehalloran]

The OP says he has a AMD Radeon HD 7950 so not Original Equiptment maybe. The Radeon 5770 is what I have and it's not a such good monitor for High Sierra as I mention above.

See my earlier post.

I have a version of that 5770 in my iMac. It runs two monitors in 10.13.4 just fine.

[dix]

I have a version of that 5770 in my iMac. It runs two monitors in 10.13.4 just fine.

On most projects you're right, but on MIDI intensive projects, while displaying a lot of MIDI info in the SE, I get dramatically better performance using El Capitan on my MP.

Of course I can't be entirely sure if it's my card that's slowing things down or if HS in general is the problem. I'd need to try a different card, to find out Hence my search for card recommendations here: viewtopic.php?f=1&t=64761

...and yes, i did do the firmware update when I installed 13.4

[NealF]

My graphics card is AMD Radeon HD 7950 3072 MB graphics.

Worked great before upgrading to HS. Don't really want to get another card now, so I'm thinking the best thing to do is revert to El Capitan. I haven't done this before, but I'm assuming my time machine will just do a restore from the time before changing.
I'm assuming everything I had before is on the backup.

[mikehalloran]

My graphics card is AMD Radeon HD 7950 3072 MB graphics.

Worked great before upgrading to HS. Don't really want to get another card now, so I'm thinking the best thing to do is revert to El Capitan. I haven't done this before, but I'm assuming my time machine will just do a restore from the time before changing.
I'm assuming everything I had before is on the backup.

A straight restore may work — I’ve never tried it over APFS. Command r into the Repair partition and follow the normal procedures. If you get the error that you can’t restore to an older OS...

Do you have a drive formatted OS 10.11? If so boot from that and reformat your SSD first. If not, you’ll need to make a boot drive from an 8G or larger USB stick or SDHC card. The instructions are easy to find and I’ve posted them here somewhere. In any case, your SSD will need to be reformatted before you can install El Cap.

I have recently had some new, inexpensive USB thumb drives not work for this. They format correctly but you get the big X when booting. Older sticks have not been a problem.

[NealF]

Sounds like a bit of work. I thought I could just hit a restore button from my backup drive and voila! Ha!

I'll check it out. Thanks.

[dix]

Sounds like a bit of work. I thought I could just hit a restore button from my backup drive and voila! Ha!

I'll check it out. Thanks.

With previous OSs it was that simple, but High Sierra's APFS may have messed that up....i don't know either, but it's worth trying via TM.

You know you can call Apple and they'll walk you through it (or tell you you it can't be done). I had a driver issue caused by a security update recently. The vendor strongly suggested I have Apple support walk me through reverting. I don't think I've called Apple support since the 90s! I didn't realize they'd give support for my old machine, but they did. It was easy to get through and the support was great.

[NealF]

I haven't called them in decades, as well. I thought anytime you'd get them on the phone it would cost. But maybe not. I'll give them a shot.

Thanks.

[mikehalloran]

Sounds like a bit of work. I thought I could just hit a restore button from my backup drive and voila! Ha!

I'll check it out. Thanks.

With previous OSs it was that simple, but High Sierra's APFS may have messed that up....i don't know either, but it's worth trying via TM.

You have never been able to reinstall an older OS without reformatting the drive. The only issue with APFS is that you may have to do it from an OS 10.11 boot drive instead of directly through Time Machine as I have already explained.

If you have an El Cap drive that you can boot from, pretty easy. If not, you'll have to make one—again easy and if you need me to look up and post the instructions again, I can.