MP 1,1-5,1 Glitch I can't figure out! Driving me crazy (Mac Pro 2009 4.1 flashed to 5.1)

[Peanutdust7]

Hi Everyone,

So i've been having an issue with my Mac pro for over a year now.
I've tried a few different things to fix it and still can't seem to find out whats wrong.
I'll be working and suddenly the screen starts to glitch with lots of random pixels (please see attached images).
Then all I can do is reboot and hope for the best, sometimes it starts up glitched again.
Sometimes it looks really bizarre almost like a water stain or a soft photoshop brush mark, but I can confirm it's all internal.

So far I have done the following in an attempt to fix it:

- Replaced 2x Apple 20" Cinema Displays (they were pretty old) with 2 new Flexscan Eizos
- Got new cables from Mac to moniters (Thunderbolt to HDMI + DVI to HDMI. The HDMI inputs are on the moniters)
- Upgraded CPU's to 2x Intel Xeon 5680 3.33ghz
- Upgraded ram to 24GB 1066 DDR3

I was going to upgrade the computer anyway but I'd hoped it would help with the problem.
Still running the original GT120 512 graphics card as I haven't had the funds yet to replace - do you reckon that could be the issue?
Also I'm currently running High Sierra.

Thank you in advance for any advice or help!

Peanutdust7

 

[tsialex]

GPU artefacts, usually caused by defective VRAM, replace it.

 

[macguru9999]

your video card is failing

 

[Peanutdust7]

ah damn, I had a hunch. So if I get a radeon rx 580 and upgrade OS i should be ok?

 

[tsialex]

ah damn, I had a hunch. So if I get a radeon rx 580 and upgrade OS i should be ok?

Run Apple Hardware Test and diagnose it correctly.

 

[Peanutdust7]

ok will do, thanks

 

[iluvmacs99]

When the GT-120 starts failing, then that is what you will see. High Sierra supports the RX580 so you don't need to upgrade to Mojave, though the RX580 support in Mojave is much better. You can get a used GT-120 pretty cheap if you can't afford the RX580 for now.

 

[fatespawn]

*disregard bad suggestion*