MP 1,1-5,1 How to - downvolt a Radeon VII

[shijan]

It seems computer freeze due Firefox HW Acceleration is common problem and may present on macOS, Win and Linux. Also seems it may happened due multiple sources, like bugs in specific GPU driver, OS version, Firefox version and even browser extensions. So it is not surprise that problem happened on my legacy 10.14.6 hackintosh system with GPU that was formally not supported at all (Radeon Pro VII flashed with Radeon VII bios). But i am still interested to fix this problem because things works smoother when HW acceleration is enabled.
One of the possible problem fixes is to increase lowest clock speed

https://www.reddit.com/r/AMDHelp/comments/11ilal5/why_is_firefox_crashing_my_pc_even_though

I done some unsuccessful tests:

Test 1. Set FreqTableGFX1,2,3,4,5,6,7,8,9,Max clocks to same 1801 value and min/max voltages to same value (1000mV) as well.
Result: Fan spins very very fast, LuxBall test 25000 instead of 50000

Test 2. Set FreqTableGFX1 to same value as FreqTableGFX2 (808), min/max voltages to same value (1000mV)
Result: OpenCore bootloader starts, but then screen flashes with artifacts and macOS can't boot.

Test 3. Set Max Core Clock to 700.
Result: LuxBall test 50000, seems Max Core Clock value don't decrease performance.

So i have a question. Is there some manual or explanation for relation between Max Core Clock, and FreqTableGFX1,2,3,4,5,6,7,8,9, and maybe to some hardcoded values in OS for this card? Same question about HBM clocks. Where those values for FreqTableGFX came from?

P.S. Currently i got stable performance with default clock 1801MHz and 981mV. Hotspot temp still 90-93. LuxBall near 52000

 

[tsialex]

So it is not surprise that problem happened on my legacy 10.6.8 hackintosh system with GPU that was formally not supported at all (Radeon Pro VII flashed with Radeon VII bios).

This is a typo, no? Radeon VII is only supported with 10.14.5 and later macOS releases.

 

[shijan]

Yes, it is typo. I mean 10.14.6

 

[shijan]

Collection of Radeon VII Overclocking/Undervolting core/voltage settings from multiple cards: https://docs.google.com/spreadsheets/d/1Iim9e_ejX3nkgxLIZ3vLu1seQ1m0lDTKUhClJpAO-Gk/edit?gid=0#gid=0

Also in other legacy thread i find possible solution to bypass low clocks, by using these parameters. Not sure if it works with Radeon VII, but testing...
<key>CFG,CFG_FORCE_MAX_DPS</key>
<true/>
<key>CFG,CFG_FORCEMAXDPM</key>
<true/>

 

[shijan]

It needs more testing, but i am almost sure that source of Firefox system freeze was overclocked and undervolted HBM. Tests like LuxMark use GPU cores but don't stress memory. Same time Ventusky website behave like gaming test. During map movements and zooming it instantly uploads/offloads new data into GPU memory, so memory controller stressed a lot with small but very strong data splashes, especially if increase animation settings. Also once i got same system freeze in Indigo Benchmark during scene loading. Many online overclocking guides describe system freeze as GPU memory related problem.

So i underclock/undervolt Core but set HBM clock FreqTableUclk3 and FreqTableUclk4 to default 1000 and MaxVoltageSoc to 1168mV and during last day it was no system freeze anymore.

Also it make sense to experiment with Memory Timing Level setting which adjust memory latency settings, which can offer performance improvements or stability issues:
Level 1 - slower timings but more stable performance.
Level 2 - faster timings but lass stable performance.

 

[shijan]

After few weeks of testing i can say that HBM 1000Mhz@1168mV@TimingLevel2 is perfectly stable. No freezes in ventusky and google maps.
1100Mhz@1168mV@TimingLevel2 produced few system freezes in ventusky and google maps.
1100Mhz@undervolted@TimingLevel2 not stable at all, many system freezes in ventysky and google maps.

Also same as older RX 580 on my system this card instantly fills data into GPU memory. Any browsed image, video or UI element is cashed inside GPU memory. It seems it don't affect performance. It is possible to empty GPU memory if turn off monitor and turn it on again.

 

[shijan]

After additional testing i discovered that system freeze also was due GPU monitoring software. If open Ventusky map in Firefox and then open iStat Menus.app menu on top of that system always freeze after few seconds. Same story if open Firefox and HWMonitorCMS2.app. So just in case if someone expect similar problems, try to disable GPU monitoring software.

UPDATE: problem also happens if i open Apple Activity Monitor GPU History window. So it seems problem happens when any app start to communicate with GPU activity data.

P.S. I tested this on two different hackintoshes with totally different CPUs and motherboard chipset generations. So problem could be due flashed Radeon Pro VII videocard itself or due some bug in Mojave drivers. Maybe i will test on Catalina or newer systems later...