Acer 3820TG: How to disable ATI graphics in the BIOS. Unlock Intel-only graphics mode (by prikolchik)
Acer 3820TG has switchable graphics ATI and Intel. A few months back, there were many people having problems with both graphics cards running at the same time. There were people who wanted to run in Intel-only graphics mode, and do that they would either use vga_switcheroo or a small program that makes ACPI calls and disables the unused ATI graphics card.
Even right now I see many people asking for help with this issue. I found a simple and quick way to disable unused ATI card in the BIOS. It involves either using a tool to unlock hidden menu in the BIOS or flashing to a modified BIOS with unlocked hidden menu.
Here I present you a way to disable ATI graphics on hardware level in the BIOS.
Many thanks to: kizwan @ NBR who discovered this method.
Apparently, Acer included a hidden BIOS menu that allows you to completely disable ATI graphics. This menu is not accessible by default -- it is hidden. There are two ways you can enable this menu. One way is to use SYMCMOS.exe tool (requires no BIOS flashing and is safe). The other way to do it is flash to a modified BIOS created by kizwan that has the hidden menu permanently unlocked.
I suggest reading about both methods. Use the one that suits you best.
Note: First method might work with other Acer laptops that have Intel/ATI switchable graphics and Phoenix BIOS. Second method is specifically for 3820 TG/TGZ/TZ
Method 1 (easy): Using SYMCMOS.exe tool to unlock hidden menu
- easiest and safe
- is NOT permanent. If you reset BIOS to default, the unlocked menu is gone
The idea is to change a BIOS setting in NVRAM using a simple DOS program.
Here is how you do it:
Step 1. Create bootable USB flash drive:
Windows: use HP Disk Storage Format Tool to format the flash drive
Linux: use GParted (or another tool) to format the flash drive to FAT/FAT32 and set the boot flag to true (select partition, right click and check flags).
Copy MS DOS files (you need to copy only 3 files: COMMAND.COM, IO.SYS, MSDOS.SYS) to the flash drive.
Step 2. Download SYMCMOS.exe (mirror) and save it to the root of the formatted flash drive.
Step 3. Connect flash drive, restart computer, and right after the POST press F12 to access the boot menu. If it does not come up, press Ctrl+Alt+Del to reboot computer and try again. It might also be disabled in the BIOS. In that case, press F2 and find "F12 boot menu" and set it to "Enabled". Press F10 and to save the changes. Try F12 again.
Step 4. Once you boot from flash drive, you should see something like:
This is DOS command prompt. Now dump BIOS settings from NVRAM into a file called Default.txt:
NOTE: It is lowercase L in front of Default.txt
symcmos -v2 -lDefault.txt
Reboot computer via power button, or press Ctrl+C.
Step 5. Turn on computer, boot into operating system.
In the root of the flash drive you should see Default.txt. Open Default.txt file with Notepad (Windows) or gedit (Linux). Locate the (0141) change the value next to it from 0000 to 0001. After you made the changes, save it to a new file, let say NEW.txt. Make sure you save the NEW.txt file on the flash drive.
Step 6. Reboot computer and boot from USB flash drive again.
Now write new BIOS settings to NVRAM:
Once the tool completes, reboot your computer.
symcmos -v2 -uNEW.txt
Step 7. Please see Accessing unlocked menu and changing graphics at the end of this post.
References: kizwan's original post
Method 2 (advanced): Flashing to the modified BIOS that has menu unlocked by default
WARNING: THERE IS A CHANCE YOU WILL PERMANENTLY DAMAGE YOUR COMPUTER. PROCEED AT YOUR OWN RISK!
- permanent. Will stay even if BIOS settings are reset to default
- relatively hard
- there is a chance that you brick your computer. It is still possible to recover via this method (BIOS recovery) though
Note: Read Method 1 to learn how to create a bootable flash drive and boot from it.
Step 1. If your BIOS is NOT v1.19, then download unmodified Acer BIOS from the support website and flash to it. You can do it by extracting the archive to a directory acer (for example) on your flash drive, then boot from it and type C:\acer\Flash.bat. It will flash the BIOS.
Step 2. If you running BIOS v1.19, then you can flash to kizwan's modded BIOS. Download it and extract it to the flash drive in directory kizwan (for example). Boot from USB drive using F12 boot menu and type This should flash the modified BIOS.
Step 3. If everything went well, you should now have a permanently unlocked advanced menu in the BIOS. Please read Accessing unlocked menu and changing graphics at the end of this post.
If something went wrong and your computer no longer boots, then please try BIOS recovery procedure
Resetting BIOS settings: If you change something wrong
If you accidentally selected the wrong video card and no longer have picture on the screen or if you changed some BIOS setting and your computer no longer boots.
You can blindly reset to default BIOS settings. Here is a list of steps:
1. Make sure computer is off.
2. Turn computer on.
3. Get into BIOS with F2.
4. Press F9 + Enter (this will load setup defaults)
5. Press ESC + Enter + Enter (this will save the changes)
6. Your computer reboots and you are back!
This should work for Acer 3820/4820/5820
NOTE: If you used SYMCMOS.exe, then you will need to unlock the hidden menu again.
If this does not help, you can reset the BIOS manually
Accessing unlocked menu and changing graphics
Now is the fun part!
After unlocking the hidden menu with either Method 1 or Method 2, turn on computer and press F2 to enter into the BIOS setup. Using arrow keys, navigate to the Intel menu.
Then navigate to MCH Control Sub-menu and change Primary Display from Auto to IGD. (NOTE: The Switchable option will disappear from the BIOS. Nothing to worry about). Press F10 to save settings and restart computer.
This will disable ATI graphics and make your computer run in Intel-only mode
List of modes:
Auto: will automatically determine the graphics mode (Switchable)
IGD: Intel-only graphics mode. The "Switchable graphics" menu will disappear from the front page of the BIOS.
PEG: ATI-only mode. Intel graphics is disabled.
PCI: DO NOT SELECT THIS! You will not see anything on the screen any more. If you selected this by mistake, see above "Resetting BIOS settings"
SG: Switchable graphics. Both cards will be available and driver will determine which card will be active.
So, if you want to turn the ATI graphics back on, simply change MCH Control Sub-menu->Primary Display back to Auto. Save via F10 and restart.
Here is a nice confirmation:
Windows: ATI graphics is gone from Device Manager and there is no longer Switch graphics menu.
Linux: ATI graphics is also gone:
$ lspci | grep -i graphics
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12)
PS: I apologize for including Windows information in the guide. I simply wanted to make this guide useful to everyone regardless of the operating system.