Issue with CSM

[JamesHewitt]

So I want to use Resizable bars as I have a 5900x / 3080. Updated both the bios and Vbios and it turns out I need to have windows installed as MBR instead of GPT.

 

I don't really know much relating to this difference and I was wondering if there's any big issues changing? Is it worth changing to enable it as well?

 

Thanks very much!

[Oshino Shinobu]

Are you trying to enable or disable CSM? Unless you have a specific reason to enable it, you should have it turned off and should be using GPT. 

 

Unsure how this relates to you wanting to use resizable bar?

[JamesHewitt]

2 minutes ago, Oshino Shinobu said:

Are you trying to enable or disable CSM? Unless you have a specific reason to enable it, you should have it turned off and should be using GPT. 

 

Unsure how this relates to you wanting to use resizable bar?

To enable resizeable bars it needs CSM disabled and it doesn't seem to boot into windows. People were saying I need to use MBR instead of GPT to do that?

[tkitch]

That sounds really sus.  MBR is old tech at this point.  GPT is much better.   I can't imagine that resizable BAR needs MBR.

[JamesHewitt]

This is what I’m getting, not detecting the NVME drive with windows 

[tkitch]

If you have Secure Boot enabled, you can't use Legacy Boot devices.  (MBR Would be Legacy, IIRC.)

So go back to your previous settings.

[JamesHewitt]

1 minute ago, tkitch said:

If you have Secure Boot enabled, you can't use Legacy Boot devices.  (MBR Would be Legacy, IIRC.)

So go back to your previous settings.

So go disable secure boot then try this again?

[tkitch]

Again, this all seems really sus.

 

Secure boot works.  GPT Works.  All of these features just plain work.

 

If you disable secure boot, go back to Legacy, and mbr?  You'll have to wipe your drive and everything.  

 

None of that sounds like you should have to do that for a GPU feature.

[JamesHewitt]

1 minute ago, tkitch said:

Again, this all seems really sus.

 

Secure boot works.  GPT Works.  All of these features just plain work.

 

If you disable secure boot, go back to Legacy, and mbr?  You'll have to wipe your drive and everything.  

 

None of that sounds like you should have to do that for a GPU feature.

That’s what I’m thinking, it seems insanely complicated. Maybe it’s an issue with 3000 series CPUS over 5000 not letting it. Thanks for the help and I’ll avoid changing it for now 

[JamesHewitt]

6 minutes ago, tkitch said:

Again, this all seems really sus.

 

Secure boot works.  GPT Works.  All of these features just plain work.

 

If you disable secure boot, go back to Legacy, and mbr?  You'll have to wipe your drive and everything.  

 

None of that sounds like you should have to do that for a GPU feature.

Just wondering, maybe it’s because insider build ? Perhaps it’s more restricted or something 

[Oshino Shinobu]

15 minutes ago, JamesHewitt said:

To enable resizeable bars it needs CSM disabled and it doesn't seem to boot into windows. People were saying I need to use MBR instead of GPT to do that?

Disabling CSM will put you in true UEFI mode, which fully supports GPT. MBR is old and shouldn't be used without a specific reason such as compatibility with legacy BIOS systems. 

 

For what it's worth, I have resizable bar enabled, using GPT for boot and CSM's disabled without any issues. 

 

Can you check in Windows to see if your drive is using GPT or MBR? With CSM disabled, GPT should work but MBR might not.

[JamesHewitt]

5 minutes ago, Oshino Shinobu said:

Disabling CSM will put you in true UEFI mode, which fully supports GPT. MBR is old and shouldn't be used without a specific reason such as compatibility with legacy BIOS systems. 

 

For what it's worth, I have resizable bar enabled, using GPT for boot and CSM's disabled without any issues. 

 

Can you check in Windows to see if your drive is using GPT or MBR? With CSM disabled, GPT should work but MBR might not.

So…might be in MBR mode….:p

[Oshino Shinobu]

1 minute ago, JamesHewitt said:

So…might be in MBR mode….:p

If it's using MBR, that'll be why it's not showing up when you disable CSM as it basically puts it in full UEFI mode which only natively supports GPT, which supersedes MBR. 

 

You'd need to change it to GPT. There are some programs that can convert to GPT without dataloss, but I can't vouch for how well they work, if at all. To do it normally, you'd need to wipe the drive and reinstall Windows using GPT.

[JamesHewitt]

1 hour ago, Oshino Shinobu said:

If it's using MBR, that'll be why it's not showing up when you disable CSM as it basically puts it in full UEFI mode which only natively supports GPT, which supersedes MBR. 

 

You'd need to change it to GPT. There are some programs that can convert to GPT without dataloss, but I can't vouch for how well they work, if at all. To do it normally, you'd need to wipe the drive and reinstall Windows using GPT.

Reinstalled windows correctly, fixed the issue :P

 

Thanks for the help!

[bovino2010]

I am also having boot problems after enabling Resizable BAR with the following components:

 

- Motherboard X570GT Biostar with BIOS version X57AS427

- Processor AMD Ryzen 5 3600

- GPU NVIDIA RTX 3070 PCYes (Palit)

- RAM 16GB (2x8GB 2400 Mhz)

- Windows 10 Pro 64 bit

- 1 Sata SSD, 1 M.2 SSD, 1 HDD

 

I am enabling only Above 4G Decoding and RES BAR, all other options are BIOS default and like this the boot crashes and i am forced to reset my BIOS and keep RES BAR disabled.