Above 4G Decoding?

For gaming with an RTX 3090, should Above 4G Decoding be enabled in the motherboard's BIOS/UEFI?

 

No,

only on mainboards that support resizable bar, once nvidia supports it.

 

@HashiruOtoko

Do not listen to Astyanax, he is too smart.
You can enable and see for yourself.
I recently enabled it (after the recent BIOS update) and I have not noticed any troubles (and performance boost as well).

 

I thought this was a feature for systems with multi GPU/SLI configurations or for bit mining?

 

This setting results in a blank screen on the majority of motherboards(worst case) otherwise performance issues occur because it is mainly meant for headless mining rigs and hasn't been implemented completely along with 64bit pcie addressing.

Nvidia drivers do not currently support above 4g decoding on the display gpu either as they adhere to prior wddm requirements that the primary gpu is mapped below 4GB.

Completely implemented and with full uefi driver support, it'd work fine. thing is most bios's don't actually implement the 64bit pcie addressing needed for resizable bar and nvidia's display driver doesn't presently post an image when the driver is mapped above 4G

 

You can enable it if your bios is operating in UEFI mode. I've had it enabled on my Asus Rampage Extreme V for a few years with no issues in Windows or gaming, though needs a driver update from Nvidia to enable in games/applications. No benefit until Nvidia gets out a driver update.

 

All of the links there are 2018 or older...

PS And overall this thing is not about graphics card, it is about PCI Express bus and devices.

 

pharma also says its working too for him, YMMV, depends on bios implementation detail.

 

My Bios optimized settings turned it on. Had it off on all previous PCs i had but this one seems to like it on. Z490 ASUS Maximus XII Formula.

 

I enabled it and seems to be working fine. Would be nice to see some before and after benchmarks, but I can't be bothered.

 

Hello there, and welcome to the world of Guru3D(.)com HashiruOtoko...

First off, Before I got really serious into 4-way sli tuning, my first motherboard for this was the Asus Z10PE-D8 WS, and if I plugged in 3 cards and started up the system, bios posted properly, whereas, if I do 4 gpu's, I would hear a beep but no picture.

So, I had to research this situation, found one person on a particular forum, with same motherboard, and couldn't get 4 gpu's to post properly upon starting up, Said to enable above 4G decoding, so I did that, and walla, Bios posted properly and all 4 gpu's are reading correctly within the device manager.

In other words, if your doing more then 3 gpu's for whatever reason, this setting is a must in order for the bios to post up properly, otherwise your left with a blank screen.

That's my personal experience on it, hope this helps.

 

Just enabled it after having it disabled since day1, should i be looking for something to happen /improve?

 

Of course! All your PCI-E devices should reach acceleration above 4G!

 

I did that in the past back when I wondered what this settings was for, there was no difference. Probably because we're only running 1 GPU and SAM is not implemented at this time. Apparently outside of SAM / Resizable BAR there's some use cases for people running multiple GPU's (mining).

 

Just updated my ASUS STRIX Z490F motherboard with a new 1002 beta BIOS this morning, I now have Resize BAR Support in my options.

 

I recently received a BIOS update which added support for these features.

I wonder when Nvidia will release a driver that supports it. Perhaps with the Cyberpunk game ready driver?

 

https://forums.guru3d.com/threads/a...-z490-motherboards.435433/page-2#post-5862932

But if you have RTX 2060 SUPER than that won't have any effect, as only RTX 3000 series is supported, for now at least.

 

Yeah, I just saw that the 30 series GPUs are the only Nvidia cards that support it for now. I do plan on getting a 3080 when I can finally find one, though.

However, now I see that the Ryzen 3000 series CPUs may never get support for it.

 

For what it's worth, someone on reddit with a Zen2 CPU and a RX 5700 seems to have support for "large memory range."

https://old.reddit.com/r/Amd/comments/k8kjrd/ryzen_3000_series_to_never_get_sam_because_it/geyu8ag/

 

Resizable BAR drivers coming in February: https://www.nvidia.com/en-us/geforce/news/geforce-rtx-30-series-resizable-bar-support/

Only Ampere cards confirmed so far.