# Z390 Taichi / ASRock Board users:  Resized BAR bioses available for testing.  Z390 Taichi featured.  PM me for details.



## R-T-B (Dec 4, 2020)

I have an experimental bios mod for this board that forces the PCIe BAR from 256MBs to 2048MBs, I'm curious of the following and need testers:

1.) Does this help performance?  Is it similar to or perhaps even recognized as "AMD SAM support?"  This isn't technically a resizable BAR, but it is a much larger one, and I'm curious if it's what AMD is doing behind the marketing talk.

2.)  How do NVIDIA cards handle this?  Do they work?  Do they benefit?

EDIT: After a brief test I can say nvidia cards work with this, benefit is...  uncertain as of now.  Need benches.

Testers wanted.  Please post if you can help, and I'll provide binaries via PM.

If you have another Z390 ASRock board, I may be able to port this function as well.

Contact me in that event as well.

Reason I am posting this here is:  I used to bios mod here for this board to remove the ME, so I'm hoping some of those users are still floating around here.


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## CyberCT (Dec 5, 2020)

Have you tried this on your motherboard? Does it work? I have the As Rock Z390 Gaming 9 motherboard. I don't know what "ME" is and would have to research it.


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## R-T-B (Dec 5, 2020)

CyberCT said:


> Have you tried this on your motherboard? Does it work? I have the As Rock Z390 Gaming 9 motherboard. I don't know what "ME" is and would have to research it.



Intel Management engine, I disable it in all my bios builds for security reaaons.  It provides the software TPM but is a major target for future (and even some present) firmware hacks, so I am politically and ethically opposed to it.  Obviously these builds no longer provide the TPM as such, but few softwares (if any?) require/use it.  TPM is mostly a dead idea for DRM.

Yes I am running it, on an nvidia card (RTX 2080 Super) though with very small (within marhin of error) gains so far.  Looking for more diverse user benches though.  I can probably target that board.  Would you like to have me attempt a build for you to test?

It's decently low risk, but with any mod bios, there is a small chance of a brick.  Didn't brick mine though, and if it did brick yours, I own a hardware flasher and would do everything in my power to help for free, FWIW.


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## purplekaycee (Dec 5, 2020)

Can't find this mobo to buy anywhere


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## R-T-B (Dec 5, 2020)

purplekaycee said:


> Can't find this mobo to buy anywhere



Basically any Z390 asrock can be supported if you are buying one for this mod, but you are more likely to get proper (ie official) support on a newer board really.  Z490 etc.


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## purplekaycee (Dec 6, 2020)

R-T-B said:


> Basically any Z390 asrock can be supported if you are buying one for this mod, but you are more likely to get proper (ie official) support on a newer board really.  Z490 etc.


Is it worth getting the z490 @ this point?
What's the difference I would get when gaming on a i910900k vs a i99900k?


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## R-T-B (Dec 6, 2020)

purplekaycee said:


> Is it worth getting the z490 @ this point?
> What's the difference I would get when gaming on a i910900k vs a i99900k?



Difference in performance is minor, basically 8 cores vs. 10 of similar speed.  Very multithreaded apps would benefit most.

Board advice should probably be a seperate thread from this though.


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## EnduringDev (Dec 7, 2020)

What is the performance increase for this bios for you?


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## W1zzard (Dec 7, 2020)

R-T-B said:


> How do NVIDIA cards handle this? Do they work? Do they benefit?


It needs driver support and ideally per-game optimization, NVIDIA has neither at this time


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## R-T-B (Dec 7, 2020)

EnduringDev said:


> What is the performance increase for this bios for you?



Minimal if anything.  I'm using nvidia right now though and I'm thinking w1zzard is spot on it: needs support.

The card driver does work with a 2GB BAR but I have yet to bench a benefit.


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## Microvoltio (Dec 10, 2020)

Tengo la Asrock Z390 Taichi, Intel I7- 9700K, Grafica Sapphire Nitro + Radeon Vega 64, NVME M.2 Samsung 970 pro, ¿tendria algun beneficio?


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## bug (Dec 10, 2020)

Microvoltio said:


> Tengo la Asrock Z390 Taichi, Intel I7- 9700K, Grafica Sapphire Nitro + Radeon Vega 64, NVME M.2 Samsung 970 pro, ¿tendria algun beneficio?


No benefit, neither of those cards can handle resizable BAR. Lo siento.


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## R-T-B (Dec 10, 2020)

bug said:


> No benefit, neither of those cards can handle resizable BAR. Lo siento.



It's not likely it will do anything at all, but given I have yet to get AMD results at all, I could still send him a bios if he wants.  Instructions would be by google translate though, which adds risk.


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## 80251 (Dec 12, 2020)

I have an Asrock Taichi z390 and a 1080Ti would your BIOS make any possible difference for me?
Kudos to disabling Intel's ME -- it's not a feature for end users, but maybe a back door for government agencies et. al.?


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## Zmon (Dec 13, 2020)

80251 said:


> I have an Asrock Taichi z390 and a 1080Ti would your BIOS make any possible difference for me?
> Kudos to disabling Intel's ME -- it's not a feature for end users, but maybe a back door for government agencies et. al.?


As others have mentioned, no. Until Nvidia introduces driver support for resizable BAR/SAM, it's functionally pointless. If you had an AMD GPU though, you could utilize it.


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## 80251 (Dec 14, 2020)

I thought AMD had restricted the use of resizable BAR not only to their video cards but to specific AMD CPU's (the latest Zen3's?).


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## R-T-B (Dec 15, 2020)

80251 said:


> I thought AMD had restricted the use of resizable BAR not only to their video cards but to specific AMD CPU's (the latest Zen3's?).



It's a PCIe spec, so no.  People are already using it on Z490.

Something to keep in mind is this isn't really a "resizable" BAR, it just enlarges it to a massive size.  I'm unsure if it's the same as what AMD is doing or not.


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## OneMoar (Dec 26, 2020)

feeling cute may decide to brick my board later
fire away @R-T-B





						ASRock > Z390 Phantom Gaming 4
					

Supports HDMI 1.4 with max. resolution up to 4K x 2K (4096x2160) @ 30Hz; 10 Power Phase Design; Supports DDR4 4300MHz+ (OC); 2 PCIe 3.0 x16, 3 PCIe 3.0 x1, 1 M.2 Key E for WiFi; AMD Quad CrossFireX™ and CrossFireX™; Graphics Output Options: HDMI, DVI-D, D-Sub; 7.1 CH HD Audio (Realtek ALC892...




					www.asrock.com
				




if I understand it correctly shouldn't the bar size be set to something as large as possible but can still be transferred in a entire clock cycle ? But not so large as it adds a bunch of overhead by reading memory thats not needed hence the dynamic part of it surely there is some global improvement to be had simply by bumping the default value a bit 

is it possible to patch in a menu to allow the user to set the bar size much like the agp aperture size


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## R-T-B (Dec 26, 2020)

OneMoar said:


> is it possible to patch in a menu to allow the user to set the bar size much like the agp aperture size



On higher end ASRock boards, very rarely (though I always try).  The best I can usually do is patch the UEFI optimized/failsafe defaults, so restoring them operates in big/standard BAR mode depending on which you restore. Actually adding menu entries is tricky.

Will look at your board after Christmas.


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## OneMoar (Dec 26, 2020)

Dank no rush at all happy holidays


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## ConsciousCoolie (Jan 6, 2021)

Hey, I just posted a question about this same topic on Reddit not too long ago. I have an asrock z390 phantom gaming itx board with an i9-9900k with an rtx 3090. I would love to be able to test this out. Would this MB be able to run this custom bios?


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## R-T-B (Jan 6, 2021)

Oh sorry nearly forgot about this.

After testing this does not work, so no more builds, unfortunately.  I will update if I find another way.


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## OneMoar (Jan 6, 2021)

???????? not work at all or not performance improvement
a side note that this method will increase the amount of 'hardware reserved' memory in windows


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## R-T-B (Jan 6, 2021)

OneMoar said:


> ???????? not work at all or not performance improvement
> a side note that this method will increase the amount of 'hardware reserved' memory in windows


Was not recognized as SAM support, and no performance gain.


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## OneMoar (Jan 6, 2021)

of course but simply increasing the bar should provide SOME improvement the bar size does not require the gpu to be aware of if thats only required for adaptive schemes such as SAM
intel spec says bar-0 default is 256MB I don't think you would ever want more then 1GB 512MB should provide some improvement without the potential hit you can get in some applications


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## R-T-B (Jan 6, 2021)

OneMoar said:


> of course but simply increasing the bar should provide SOME improvement the bar size does not require the gpu to be aware of if thats only required for adaptive schemes such as SAM
> intel spec says bar-0 default is 256MB I don't think you would ever want more then 1GB 512MB should provide some improvement without the potential hit you can get in some applications


I was not able to confirm any increase.

I can still make a build for you onemoar if you want to test more extensively.  I feel you might be a good tester for a real detailed look, but just be warned impact is minor at best.

I set it to 2GBs, you think 1GB might be better?


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## JoeyM (Jan 7, 2021)

Hello everyone, I know this thread is specifically about the DIY modding of the Z390 Taichi / ASRock Board. However, I would encourage all of you to consider signing the petition that calls on Intel (as well as all motherboard manufacturers) to release a bios that would enable Smart Access Memory (resize bar) on all Intel 300 series motherboard.

In addition to signing the petition, it would be great if you also assisted in spreading the word!









						Sign the Petition
					

Enable resize bar (smart access memory) for Intel 300 series motherboards




					www.change.org


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## mouacyk (Jan 7, 2021)

Petition · Intel: Enable resize bar (smart access memory) for Intel 300 series motherboards · Change.org

Signed.  Please need everyone to do all they can.  In no way, are 300 motherboards obsolete, even if they are EOL.


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## bug (Jan 7, 2021)

mouacyk said:


> Petition · Intel: Enable resize bar (smart access memory) for Intel 300 series motherboards · Change.org
> 
> Signed.  Please need everyone to do all they can.  In no way, are 300 motherboards obsolete, even if they are EOL.


Petition to add support to a product that doesn't receive support anymore. Smart. Real smart.


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## mouacyk (Jan 7, 2021)

bug said:


> Petition to add support to a product that doesn't receive support anymore. Smart. Real smart.


It's a feature that should have been there from the beginning anyway.


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## bug (Jan 7, 2021)

mouacyk said:


> It's a feature that should have been there from the beginning anyway.


Oh, that changes things. Good luck.

(Btw, you're wrong. Resizable BARs is an optional PCIe feature: https://pcisig.com/specifications?speclib=resizable+bar )


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## OneMoar (Jan 7, 2021)

its optional in that the bios needs to support it there is no hardware limitation that I am aware of that would prevent it from being supported going all the way back to pcie 2.0


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## bug (Jan 7, 2021)

OneMoar said:


> its optional in that the bios needs to support it there is no hardware limitation that I am aware of that would prevent it from being supported going all the way back to pcie 2.0


Up until now, the limitation was there was no hardware to test this with. The hardware that exists today can be counted on one's fingers and yields minimal performance changes. If you were a motherboard maker, you wouldn't bother back-porting this feature for 2% more fps either.


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## R-T-B (Jan 8, 2021)

JoeyM said:


> Hello everyone, I know this thread is specifically about the DIY modding of the Z390 Taichi / ASRock Board. However, I would encourage all of you to consider signing the petition that calls on Intel (as well as all motherboard manufacturers) to release a bios that would enable Smart Access Memory (resize bar) on all Intel 300 series motherboard.
> 
> In addition to signing the petition, it would be great if you also assisted in spreading the word!
> 
> ...



I fully endorse this.  Will sign when I get home.

I'm not asking for a tested bios, just a board beta release or something to hack on.


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## OneMoar (Jan 8, 2021)

I wonder how this behaves on boards with PLX chips the PLX chip needs to map the registers some how


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## bug (Jan 8, 2021)

OneMoar said:


> I wonder how this behaves on boards with PLX chips the PLX chip needs to map the registers some how


It may not even be supported in that configuration. The actual spec is not public, unfortunately


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## OneMoar (Jan 8, 2021)

bug said:


> It may not even be supported in that configuration. The actual spec is not public, unfortunately


thats what I was getting at  would explain some of the weird benchmark results we are seeing


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## 80251 (Jan 12, 2021)

I'm guessing the bar size should never be larger than the actual address space of the VRAM right?


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## lesp4ul (Jan 14, 2021)

MSI says they will support Resizeable BAR from H310 : https://www.msi.com/news/detail/010ad17a3b1868e7e219a11274738ea7

Hello, Asrock??!


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## JoeyM (Jan 16, 2021)

Yes, MSI has recently decided to enable resize bar for their z390 motherboards: https://www.msi.com/news/detail/010ad17a3b1868e7e219a11274738ea7

I would strongly recommend that anyone who hasn’t already signed the petition do so now. If you already signed it, please share it! This may help encourage all other motherboard manufacturers to follow suite.
Link to the petition:  http://chng.it/LKLksG4yQv


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