Resizable BAR. What is it?

Baldbloke · 30 Oct 2021 at 17:53

I had a quick google. It seems to allow gpu memory access from the cpu.
But only in certain games and on certain hardware.

I play Automobilista 2 (badly) and Assetto Corsa (very badly) in VR. Almost exclusively.

Would this Resizable BAR thingymabob be of any use to me and would I need to enable it in settings/bios/game?

I have a Ryzen 5 3600 and an rtx 3080ti.

Muchly thanks in advance.

FlyingFish · 30 Oct 2021 at 19:12

Your motherboard needs to support this, so check for a bios update for this feature, then enable it in bios. It will then be enabled in windows. As far as I know there isn't a per app/ game toggle.
For some games there is a benefit and for some there is a negative effect.
Is you have horsepower to spare then just leave it enabled (like I do).
If not, you need to look at each game you play, and see if there is a benefit.

Skynet5 · 30 Oct 2021 at 20:36

I don't think it's confirmed to work on 3000 Ryzen. I haven't bothered. Gains appear to be minimal even on a supported CPU.

varkanoid · 30 Oct 2021 at 21:01

Baldbloke said:
I had a quick google. It seems to allow gpu memory access from the cpu.
But only in certain games and on certain hardware.

I play Automobilista 2 (badly) and Assetto Corsa (very badly) in VR. Almost exclusively.

Would this Resizable BAR thingymabob be of any use to me and would I need to enable it in settings/bios/game?

I have a Ryzen 5 3600 and an rtx 3080ti.

Muchly thanks in advance.

3000 series was enabled March 2021 for SAM (AMD's name for Resize BAR) so your CPU is compatible.

Check your BIOS usually has an on/off top right for Resize BAR to enable it
If not check the BIOS downloads for your motherboard and see which BIOS update incorporated it.

Once enabled make sure Nvidia drivers are latest version.

Check GPU-Z (bottom right) and it shows its enabled or disabled.

Its free, it might give you a boost in certain games, whats not to like ?

opethdisciple · 31 Oct 2021 at 00:19

It worked for me on my 3700x.

With an Nvidia GPU, Nvidia turn it on and off per game so no need to worry about degraded performance.

Enable it.

Sarge2255 · 31 Oct 2021 at 00:36

Resizable can be turned on in your motherboard bios, some GPUs may also need a bios update for it to work.

Resizable bar only gives more fps in a list of Nvidia selected games like rdr2 , Assassin’s Creed valhalla,.....

Cooper · 31 Oct 2021 at 10:06

Resizable BAR? its just another e-peen box to be filled in GPU-Z, thereby relieving the cards owner of an overwhelming sense of terror & dread of FOMO...

Minstadave · 31 Oct 2021 at 10:10

Cooper said:
Resizable BAR? its just another e-peen box to be filled in GPU-Z, thereby relieving the cards owner of an overwhelming sense of terror & dread of FOMO...

You OK hun?

Cooper · 31 Oct 2021 at 10:18

Minstadave said:
You OK hun?

No.

The clocks went back, its dark & ******* down with rain, I have a dentists appointment on Weds that will likely involve pain, Ocado has sold out of my favourite chocolate spread for Thursdays delivery & I had to do a BIOS update to get resizeable BAR working on my Z390 board & BIOS updates stress me out, which resulted in absolutely ZERO perceivable difference to performance with my 3080.

Expect more grumpy posts today.

Does that answer your question..

Baldbloke · 31 Oct 2021 at 13:34

Thank you so much for the replies and info. I downloaded GPUZ. It states Resizable bar is disabled. So I had a look on MSI site. Briefly read a document there and it suggests updating Vbios. Erm, nah, Not with the price of gpu cards these days. I'm not willing to fiddle with Vbios. I'll leave it be.

Cooper said:
No.

The clocks went back, its dark & ******* down with rain, I have a dentists appointment on Weds that will likely involve pain, Ocado has sold out of my favourite chocolate spread for Thursdays delivery & I had to do a BIOS update to get resizeable BAR working on my Z390 board & BIOS updates stress me out, which resulted in absolutely ZERO perceivable difference to performance with my 3080.

Expect more grumpy posts today.

Does that answer your question..

I hate to make you jealous but, The good news is.... I'm having a great day. Oculus just sent me an email stating I was level 3 contributor (I've made two posts!

And... I got a picture of a BADGE! Can one mans day get any better than this? Wow!

varkanoid · 31 Oct 2021 at 16:05

Baldbloke said:
Thank you so much for the replies and info. I downloaded GPUZ. It states Resizable bar is disabled. So I had a look on MSI site. Briefly read a document there and it suggests updating Vbios. Erm, nah, Not with the price of gpu cards these days. I'm not willing to fiddle with Vbios. I'll leave it be.

It was only to be done on early 3xxx cards if you bought a later one it was already enabled ie if it was purchased after 31/03/21 then it will have Resize Bar enabled in the GPU firmware.

https://nvidia.custhelp.com/app/answers/detail/a_id/5165/~/nvidia-resizable-bar-firmware-update-tool

download the tool, run it then it will tell you whether you need to update the firmware or not, it pauses before you do anyway so you can back out if it says it needs a firmware update.
I did it on my 3080 as I got that Xmas Eve it was very easy and no problem. Loads of people have done it fine. Just depends when you bought it.

BUDFORCE · 31 Oct 2021 at 17:14

Cooper said:
No.

The clocks went back, its dark & ******* down with rain, I have a dentists appointment on Weds that will likely involve pain, Ocado has sold out of my favourite chocolate spread for Thursdays delivery & I had to do a BIOS update to get resizeable BAR working on my Z390 board & BIOS updates stress me out, which resulted in absolutely ZERO perceivable difference to performance with my 3080.

Expect more grumpy posts today.

Does that answer your question..

Yup pretty much sums it up.

Basically don't bother.

Sarge2255 · 31 Oct 2021 at 19:04

Resizable bar does give some performance boost, listed games. AC Valhalla I can see a small boost

Haggisman · 1 Nov 2021 at 08:23

lnoton said:
I don't think it's confirmed to work on 3000 Ryzen. I haven't bothered. Gains appear to be minimal even on a supported CPU.

It is enabled for 3xxx Ryzen, I've got it working on my 3700x.

Can't speak for Nvidia cards, but with my RX 6800 I got a reasonable increase in the games I tested at the time, ~7% in RDR2, 4% in Metro Exodus Enhanced Edition. Sure those aren't exactly game changing figures, but can't really complain for a free "upgrade"

Sarge2255 · 6 Nov 2021 at 19:20

Haggisman said:
It is enabled for 3xxx Ryzen, I've got it working on my 3700x.

Can't speak for Nvidia cards, but with my RX 6800 I got a reasonable increase in the games I tested at the time, ~7% in RDR2, 4% in Metro Exodus Enhanced Edition. Sure those aren't exactly game changing figures, but can't really complain for a free "upgrade"

Resizable Bar only works on Nvidia GPUs

Purgatory · 6 Nov 2021 at 19:58

Sarge2255 said:
Resizable Bar only works on Nvidia GPUs

Can you stop spreading rubbish... It works on AMD cards too.. it is called SAM smart access memory.

REBAR (Resizable Bar) as the official specification name is exactly the same thing AMD calls Smart Access Memory.

All the new gpus this gen (AMD 6000 series and Nvidia 30 series, Also AMD has enabled it for their 5700 & xt) have it, some nvidia cards that came out earlier this generation may require a VBIOS update.

https://www.amd.com/en/technologies/smart-access-memory

https://www.nvidia.com/en-gb/geforce/news/geforce-rtx-30-series-resizable-bar-support/

Update info for Nvidia cards that may require a VBIOS update.

https://nvidia.custhelp.com/app/answers/detail/a_id/5165/~/nvidia-resizable-bar-firmware-update-tool

Just make sure to have a cpu and motherboard (with updated BIOS for the Rebar feature) that can support Rebar aka smart access memory as AMD call it.

Ryzen 3000, Ryzen 5000 cpus and some previous gen Intel cpus and of course Alder Lake supports it on Z690 platforms.

oldestgregg · 6 Nov 2021 at 22:02

For my TUF 3090 it was a couple of FW updates (both GPU and BIOS of MOBO) then I got anywhere between 4 and 8% increase depending on the game. Not amazing but free.

However Ive lost a few frames given they disabled it in Far Cry 5 for some reason!

Haggisman · 7 Nov 2021 at 08:48

Sarge2255 said:
Resizable Bar only works on Nvidia GPUs

I'm not sure how you've managed to come to that conclusion when you're replying to a post where I've literally said I've enabled it on my AMD card and seen an improvement? Just because AMD have decided to give the technology a fancy name (Smart Access Memory), doesn't mean it doesn't exist.

That's like saying a Big Mac isn't a burger because it's called a Big Mac :rolleyes:

Baldbloke · 7 Nov 2021 at 08:57

varkanoid said:
It was only to be done on early 3xxx cards if you bought a later one it was already enabled ie if it was purchased after 31/03/21 then it will have Resize Bar enabled in the GPU firmware.

Oh happy days. I just needed to enable it in motherboard bios. Thank you. Haven't tried it yet. Will it make a difference? Dunno, but.....

Cooper said:
Resizable BAR? its just another e-peen box to be filled in GPU-Z, thereby relieving the cards owner of an overwhelming sense of terror & dread of FOMO...

Now I can stroll down our local high street, exuding such confidence, women will be able to tell just by looking at me "He's got Resizable BAR enabled, I bet. Ooh

".

Sarge2255 · 7 Nov 2021 at 14:28

Haggisman said:
I'm not sure how you've managed to come to that conclusion when you're replying to a post where I've literally said I've enabled it on my AMD card and seen an improvement? Just because AMD have decided to give the technology a fancy name (Smart Access Memory), doesn't mean it doesn't exist.

That's like saying a Big Mac isn't a burger because it's called a Big Mac

SAM, ok , I read it as you meant the Nv one.