# Resizable BAR / SAM for Ryzen 3000 -  ASROCK X570 Taichi



## F7GOS (Jan 26, 2021)

Looks like ASRocks latest 4.00 BIOS has enabled S.A.M for Zen 2 based 3000 and 4000 CPUs.

Decent little performance bump on the RX 6800


----------



## oobymach (Jan 26, 2021)

Apparently works with gtx 3000 series cards as well.


----------



## Zach_01 (Jan 27, 2021)

I also notice the Re-Size Bar setting in my BIOS a couple of BIOS versions back.

AorusPro X570, R5 3600, 5700XT. Didn’t test it though, as my GPU drivers are from September 2020.


----------



## StormLightningSL (Jan 27, 2021)

I don't think Resizable BAR support is enabled on 5700XT yet.
I believe I read somewhere that it is only enabled in AMD 6000 series and Nvidia 3000 series.

I'm looking for a 3080, maybe 2X (for two separate systems), but it's going to be a dream for a while with the current situation.


----------



## ratirt (Jan 27, 2021)

StormLightningSL said:


> I don't think Resizable BAR support is enabled on 5700XT yet.
> I believe I read somewhere that it is only enabled in AMD 6000 series and Nvidia 3000 series.
> 
> I'm looking for a 3080, maybe 2X (for two separate systems), but it's going to be a dream for a while with the current situation.


Does this feature is CPU or GPU enabled or is it the motherboard that allows it? If motherboard supports the BAR feature would it enable the CPU to make the use of it despite of the GPU?
The BAR feature is not anything new and if there is an interface, the CPU can utilize it. I think the CPU is the main beneficent here not the GPU. Maybe both CPU and GPU have to support this? I really think it is the CPU that matters here. If the 3000 series can do it I'm sure all CPUs would be able to utilize this in certain manner.

I been trying to find a 6800XT liquid but with no luck. There are no 3080 either. The only cards I can buy now are the overpriced 6900XT and 3090. That sucks.


----------



## INSTG8R (Jan 27, 2021)

StormLightningSL said:


> I don't think Resizable BAR support is enabled on 5700XT yet.
> I believe I read somewhere that it is only enabled in AMD 6000 series and Nvidia 3000 series.
> 
> I'm looking for a 3080, maybe 2X (for two separate systems), but it's going to be a dream for a while with the current situation.


It kinda is of you check the GPU under Device Manager there‘s something like “Large Memory Pool” (can’t say specifically not at my PC) tho I’ve seen no performance difference so far.


----------



## Zach_01 (Jan 27, 2021)

SAM is a CPU aid.-
CPUs previously used only a fixed 256MB of GPU's VRAM. Now the CPU can use as much as it can or as much as is available. Thats why we saw this now that GPUs got above 8~10GB of VRAM.
Even if its enabled on a 5700XT (or any 8GB card) it would be useless if the GPU game data already fills the VRAM.


----------



## StormLightningSL (Jan 30, 2021)

That's great info! I had no idea it worked like this.

So, if i understand correctly, GPUs with more VRAM will benefit more from SAM/BAR resizing. If that is the case, then the 3090 cards will get a huge benefit along with the 6800XT and 6900XT, whereas the 3080 and lower cards may not see such a big bump in performance. I guess the CPU would use the VRAM as cache memory of some sort to speed up the performance of the GPU?


----------



## Zach_01 (Jan 30, 2021)

Its not as simple though...
Needs board support, GPU drivers support and Game support to fully utilize this feature.
By this (if and when it works) its like having a faster CPU. Also helps GPU if CPU is faster.
I would guess not for all resolutions though. 1080p sure, maybe 1440p too. But for ultra wide and 4K I wouldn't expect much, if nothing at all.


----------



## StormLightningSL (Jan 31, 2021)

Zach_01 said:


> Its not as simple though...
> Needs board support, GPU drivers support and Game support to fully utilize this feature.
> By this (if and when it works) its like having a faster CPU. Also helps GPU if CPU is faster.
> I would guess not for all resolutions though. 1080p sure, maybe 1440p too. But for ultra wide and 4K I wouldn't expect much, if nothing at all.


I guess it is a little more complicated than I thought. Game support can hardly be expected except with new titles. And higher resolutions is where the difference in performance would be useful.

Maybe this is another one of those statistics that don't translate into much performance benefit for those who really need it.


----------



## Zach_01 (Jan 31, 2021)

In theory it would be more beneficial to CPU demanding gaming. Thats on specific games and lower resolution (1080p) for almost all games. On higher resolutions its the GPU that counts more. At 4K for example SAM would have the least impact. It doesnt matter if the CPU is 3600/10400f or a Ryzen7/9, Core i9.


----------



## StormLightningSL (Feb 1, 2021)

I understand. Thank you!


----------

