GTX 1070 in 5,1 Mac Pro - no 4k?

[h9826790]

Thank you again for your thorough input! I was tossing the idea around of dual 380's but didn't really now how to power it (Pixlas mod) I would like to be open to the possibility of going to higher resolutions so 8GB VRAM should work pretty good and keep me "future proof" for some time. If you are interested there is a pre-order for RX 580 Pulse on UK Amazon. Im not too sure if they ship to HK but if they do, it would be a pretty good deal. Im thinking of getting one, but don't know when the card will arrive.

No Pixlas mod required. Just need to downclock the card to around 880MHz and downvolt to 0.968V. Then the card's performance will drop about 5%, but draw 20% less power. It will make the card pull 75W or less (from BOTH 6pins in total) under normal situation (e.g. Video editing). And up to ~105W in Furmark. 105W of course already outside the cMP's official limit for a single 6pin, but still within the practical limit. Therefore. it's totally possible to drive one 380 by a single mini 6pin. Or two 380 by just the dual mini 6pins.

The following link is my power draw test from 2x 7950 setup (with NO Pixlas mod or extra PSU), the dual 380 setup will be very similar to this.

https://forums.macrumors.com/thread...or-approaching-silence.1982499/#post-23120938

 

[MCMX]

Yes, he's most likely seeing the last part of the boot process, not the real deal (e.g. boot manager, single user, FileVault, OS without drivers, ...).

Regarding your 4K issue: Are you sure that macOS isn't outputting HiDPI 1080p (which is 4K with everything rendered twice as big). Native 4K is usually unavailable by default because it would be too small to read.

It's usually a good idea to install SwitchResX (or similar apps) to get all available resolutions and settings.

So SwitchResX does allow me to get the 3840x2160 4k resolution, thank you for the suggestion, seems to be running smoothly. Also as you guessed, all the lower resolutions were running HiDPI if I'm reading SwitchResX's window correctly.

 

[eltoslightfoot]

SwitchResX is the bomb. I use it all the time.

 

[Synchro3]

SwitchResX is a must-have for years.