[Success] XFX RX 6600 XT graphics card in Monterey 12.2.1

[miliuco]

Although graphics cards assembled by XFX have negative comments in Hackintosh forums by having custom BIOS that can be more problematic for macOS that of other brands, I have installed a XFX QICK 308 AMD Radeon RX 6600 XT 8GB in Monterey 12.2.1 and the result has been excellent, installation was very simple and performance is much higher than that of the previous card, RX580 8GB. This card is one of the 6600 XT cheapest even though it can still be considered expensive compared to what would be logical in other circumstances (shortage of components and mined cryptocurrencies). The main components of my computer are Z390 Aorus Elite board and Intel i9-9900K CPU.

Current macOS status of AMD 6000 series graphics cards is:

• Working on macOS
  - Family Navi 21: 6800, 6800 XT and 6900 XT (since Big Sur 11.4)
  - Family Navi 23: 6600 and 6600 XT (since Monterey 12.1)
• NOT working on macOS
  - Family Navi 22: 6700 XT
  - Family Navi 24: 6400, 6500 and 6500 XT.

Of course 6800 and 6900 series are clearly more powerful than the 6600 but their current market price is very high. The 6600 XT has higher performance than the 6600 and, this particular model of XFX, can now be found for a price of approximately 500-550 €.

The model is long size but no longer than the XFX RX580 it will replace. Surprisingly, it's even slightly lighter, probably because of the metal housing that the RX580 incorporates. Requires 8 pin power connector and recommended power supply is at least 600-650W. It has 4 DisplayPort ports and 1 HDMI port.

Installation

Physical placement of the card does not deserve comment, it's like any other PCI-e slot card.

Installation on macOS is very simple. The same EFI with OpenCore 0.7.8 (Lilu and WhateverGreen included) that worked with the RX580 works for the 6600XT with a single change: add agdpmod=pikera in boot-args to prevent the screen from going black on the desktop.

The card is well recognized as seen in System profile.


Working on macOS

Overall performance is very good, smooth, with 2560x1440 resolution at 60Hz on a 4K monitor. The score in the GeekBench 5 test is almost 60% higher than the RX580.




Working on Windows

Many Hackintosh users have double booting with Windows. Here the impressions are also very good, system has kept the same AMD drivers without requiring update.

The score in the Geeks3D FurMark test is double with the RX 6600 XT (approx. 6145) than with the RX580 (approx. 3050).

Temperature sensor

Starting with the Radeon VII model, it is necessary to use kexts to read the temperature of AMD graphics cards since macOS stopped exposing that data directly. This also applies to the 6000 series. To know the temperature of the card you can use aluveitie's RadeonSensor. It consists of 3 elements:

• Radeon sensor.kext: Lilu plugin to read card temperature
• SMCRadeonGPU.kext: to export data via VirtualSMC to monitoring tools such as iStat Menus
• RadeonGadget.app: to display the temperature in the menu bar, it requires RadeonSensor.kext only.

Note: SMCRadeonGPU.kext has to go after RadeonSensor.kext in the config file.plist of OpenCore and of course both after Lilu and VirtualSMC.

I have tested these 2 extensions together and they seem to work well, iStat Menus adds the temperature of the 6600 XT as one more sensor to display in the menu bar.

Resizable BAR (ReBAR)

Note: you can read about ReBAR here.

RX 6600XT cards support ReBAR. To activate this feature you must:

• Enable it in BIOS menu (usually next to Above 4G Decoding option, ReBAR is displayed when enabling this other option)
• Set config file.plist in order for OpenCore to boot with ReBAR enabled, you have to set the value of Boot >> Quirks >> ResizeAppleGpuBars=0 (instead of -1, default value). Note: UEFI >> Quirks >> ResizeGpuBars must always be -1.

I have tested the card with ReBAR on and off and I have not noticed any difference. GeekBench 5 test scores on macOS and FurMark on Windows have been virtually identical.
It is likely that with a CPU of 10th generation or newer and games of big graphic demand the performance will improve with ReBAR enabled but, at least in my system, there is no gain in it.

 

[RUSSKIYVOLK]

Hi, what is the temperature of your graphics card in macOS? I have a 6600 XT Red Devil. It reaches 57 degrees in idle time? And I do not know how to fix it. Everything is fine in the Windows-30-35 degrees.

 

[miliuco]

@RUSSKIYVOLK
Using RadeonSensor, temp is about 45° when idle or low load, internet and office tasks, going up to 50-55 with higher load.
Temp reaches 70-80 with stress tests like Unigine Valley.
Fans spin over 60.
Windows usually is about 40-45.

 

[RUSSKIYVOLK]

@RUSSKIYVOLK
Using RadeonSensor, temp is about 45° when idle or low load, internet and office tasks, going up to 50-55 with higher load.
Temp reaches 70-80 with stress tests like Unigine Valley.
Fans spin over 60.
Windows usually is about 40-45.

Understood, thank you!

 

[miliuco]

Understood, thank you!

We are talking about 2 graphics card models assembled by 2 different manufacturers. Mine has 3 smaller fans and yours has 2 larger ones. Base clock frequency seems to be lower on mine than yours, from what I've read. Turbo frequencies are no different.
I think your card has a button to switch between 2 BIOS, powerful and silent, have you tried both modes to see if temperature and performance change?
PC case also matters, although mine is a cheap case with few ventilation options.
Is there any other card or item that gets in the way of RX fans?

 

[RUSSKIYVOLK]

We are talking about 2 graphics card models assembled by 2 different manufacturers. Mine has 3 smaller fans and yours has 2 larger ones. Base clock frequency seems to be lower on mine than yours, from what I've read. Turbo frequencies are no different.
I think your card has a button to switch between 2 BIOS, powerful and silent, have you tried both modes to see if temperature and performance change?
PC case also matters, although mine is a cheap case with few ventilation options.
Is there any other card or item that gets in the way of RX fans?
View attachment 542956

It doesn't matter

 

[b7anka]

@miliuco I just bought the same card as yours but even with the agdpmod=pikera boot arg once it gets to the login screen it goes black. I'm also using the iGPU from the 10700k cpu which is the intel UHD 630. My motherboard is a MSI z490 A pro. Do I have to do something to be able to use both gpus without one going black. Do you use an SMBIOS with no iGPU? Thanks for the info on sharing the success of the 6600 XT (that's why I bought one after reading this post). Out of curiosity I paid 548 € for mine.

 

[miliuco]

@b7anka
Although I have tried iMac19, 1 with iGPU in headless mode and also with iGPU as main card, the SMBIOS that works best on my PC is MacPro7,1 with iGPU disabled in BIOS. In this way macOS works very well and I can play DRM content (Apple TV app, Netflix or Prime Video in Safari...).

To use MacPro7,1 I add RestrictEvents.kext (not required with iMac).

Our CPUs are different so I can't help you with the black screen when iGPU is enabled.
But think that the main reason to have the Intel 630 active in headless mode is hardware video encoding or help with computing tasks. However, the difference in performance between the iGPU and the RX 6600 is so great that, when you enable the Intel 630, video encoding is probably worse using both graphics cards at the same time than it is when you use only the dGPU.

How you have the iGPU in config.plist so that both cards are enabled? I think you just need to put the property AAPL,ig-platform-id with the value 0300C89B, nothing else. If you have more keys, leave only this one and try to see if it works.

There is a free Blackmagic Raw Speed test (App Store) that you can do with iGPU enabled and disabled, in my PC the score with only the AMD (Intel disabled in BIOS) is much higher than the score with both cards enabled.

By the way, my RX 6600 cost 540€, as yours.

 

[TurbineSeaplane]

I'm having the same high idle temperature problem on an XFX 6600 XT that just arrived.

It's always in the low to mid 50's and the fans never spin.

This seems like a really bad deal long term, particularly with my Hack living on the macOS side the majority of the time (I only boot over to Windows for gaming)

 

[miliuco]

@TurbineSeaplane
This behavior is the same that other RX 6600 XT users see.
In Windows the temperature is usually 10 degrees lower than in macOS. On macOS it stays around 50º.
The fans start by default from 60º so most of the time they are stopped (zero rpm).

There are users who have created from Windows what is called PowerPlay tables with the zero rpm option of the fans disabled so that they are running all the time and have lower temperatures, but it is a difficult task. I have never tried it. The tables are created on Windows and added to the OpenCore config.plist file.