Zen 4 iGPU - Memory Bandwidth Incorrect

[The Von Matrices]

I just bought a new 7950X system and took a look at GPU-z. There's a few bugs I noticed (or maybe I'm just misunderstanding things)

• The memory bandwidth is reported as double what it should be for DDR5-4800. 128 bit DDR5-4800 should be 76.8 GB/s.
• My 3090 shows resizable BAR as enabled, but the iGPU shows it as disabled in the exact same system at the same time.
• It shows 512MB as the memory size - that's the dedicated amount set in the BIOS but is that the correct way it should be reported since it's sharing system memory? I'm not sure that's wrong but I've never checked an iGPU before.

Great work on this software, as always. Just trying to report bugs to improve it for others.

 

[AsRock]

I see the amount i selected in bios which is 4GB all so see system reserved ( task Manager ) is now 4.4GB so maybe look there and see how much reserved ram you have.

I don't have the driver installed for it as it was making problem with a game so. I just jumped in the bios picked 4GB and enabled it.

 

[The Von Matrices]

I just looked into the details of resizable BAR, it's apparently an unsupported GPU, so that's not a bug.

 

[tabascosauz]

GPU-Z only ever shows what is set in BIOS for iGPU, not a on the fly number

 

[W1zzard]

My 3090 shows resizable BAR as enabled, but the iGPU shows it as disabled in the exact same system at the same time.

This is totally expected. The BAR support is per-device, it's not universal. AMD confirmed to me that the IGP does not support resizable BAR. It really doesn't need it, because its memory is in the CPU's memory pool anyway

It shows 512MB as the memory size - that's the dedicated amount set in the BIOS but is that the correct way it should be reported since it's sharing system memory? I'm not sure that's wrong but I've never checked an iGPU before.

I felt like showing the number was better than showing "N/A" or "System Shared". I vaguely remember that on some platforms where I can't read the memory size I'm showing something like the former.

 

[The Von Matrices]

This is totally expected. The BAR support is per-device, it's not universal. AMD confirmed to me that the IGP does not support resizable BAR. It really doesn't need it, because its memory is in the CPU's memory pool anyway

The logic behind AMD not supporting resizable BAR with IGPs makes sense. However, I've always found the use of the word "disabled" to be confusing because it implies that you can enable it. I think "unsupported" would be a better way to describe resizable BAR on these IGPs and older GPUs, but it's only a minor quibble.

I felt like showing the number was better than showing "N/A" or "System Shared". I vaguely remember that on some platforms where I can't read the memory size I'm showing something like the former.

Makes sense. I have no complaints.

 

[Ruru]

However, I've always found the use of the word "disabled" to be confusing because it implies that you can enable it.

Agree on that, same goes with Crossfire/SLI these days.

 

[Vya Domus]

I am not sure if resizable BAR support even makes sense for iGPUs considering the memory is shared with the system.