Intel Arc A770 Tested with PCIe 3.0 and Resizable BAR Off

[defaultluser]

That's the definition of Resizeable BAR

and kids, if you just happen to have bugs in this early feature, then you may be stuck with that 30% performance hit permanently!

Resizable Bar not working.

I have a TUF-RTX3080-10G-GAMING-PD Graphics card with VBIOS version 94.02.42.40.64 with a build dating back to 2020-11-26, I'm trying to enable resizeable bar. Still, it just won't work, I'm suspecting it's an outdated VBIOS, but when I attempt to update the VBIOS with Asus' RTX3080_V5 file it...

www.techpowerup.com

 

[lexluthermiester]

That's the definition of Resizeable BAR

Ah ok. I need to deep dive on the details of ReBar now that it's going to be a required thing..

 

[defaultluser]

Ah ok. I need to deep dive on the details of ReBar now that it's going to be a required thing..

only for Intel, because they are cheating, by ignoring half the world driver states!

AMD tends to see better performance than NVIDIA, but its not nearly that insane a bump as lintel half-assed-optimization is; but we will have to see how much the performance improves for the out-of-order NVIDIA Ada 4090

 

[lexluthermiester]

only for Intel, because they are cheating, by ignoring half the world driver states!

AMD tends to see better performance than NVIDIA, but its not nearly that insane a bump as lintel half-assed-optimization is; but we will have to see how much the performance improves for the out-of-order NVIDIA Ada 4090

We can do without the brand bashing here.

 

[Dr. Dro]

The 25-28% loss is actually less than what I expected given they admitted that there was no optimization for traditional systems. I was kind of expecting some bizarre results like, this is so bad G80 could beat it, but alas that is not the case. Maybe Intel will be able to adjust their driver codebase to improve behavior sometime, it doesn't have to perform to the same extent as a modern PC, but if they get rid of the inconsistencies, it'll be enough, IMO.

so resizable BAR or SAM not for advantage anymore, but become requirement.. its more like athletes doing doping or they cannot running..

That's a bit harsh. GPU engineers had reasons not to implement resizable BAR all this time, after all, as W1zz says, it's not a new feature to the PCI Express specification.

End of the day, it's a nothing burger: while I think it is a bit of a bummer and that Intel could score many more sales to those who own and wanted to breathe some new life on older platforms with a reasonably priced product, at the end of the day it's really an all-new GPU architecture backed by all-new software, designed for new PCs first and foremost. I don't see the harm in that, in fact, Intel may have a distinct upper hand in the long game - AMD recently felt the weight of its aging software stack that just couldn't be bandaged anymore and set out to rewrite their Direct3D and OpenGL stack, this last one completely from scratch. It's a very difficult, expensive and risky move for a software engineer, that.

 

[trsttte]

only for Intel, because they are cheating, by ignoring half the world driver states!

ReBar has been a thing in the pcie spec for a long while, it just so happens no one bothered with it until AMD realised it could be an advantage and sold it as a new feature under "SAM - Smart Access Memory" (it's supposedly rebar plus some amd fairy dust but the main idea is basically standard rebar)

It's a new thing in the consumer space but older boards as far back as amd zen1 and intel 10th gen (and unnofficially some intel 9th/8th gen boards even) support it, nothing wrong with a new gpu requiring it, hardware is always moving forward and there are other choices if you don't want to update your older platform right now.

It's obvious Intel designed things differently so there's a big performance hit with/without rebar but I think a more interesting question is what the fuck is AMD and nvidia doing (or rather not doing) that ReBar hardly matters? It's supposed to offer a performance advantage (probably not huge like with Intel, but clearly meaningfull), why doesn't it?

 

[defaultluser]

ReBar has been a thing in the pcie spec for a long while, it just so happens no one bothered with it until AMD realised it could be an advantage and sold it as a new feature under "SAM - Smart Access Memory" (it's supposedly rebar plus some amd fairy dust but the main idea is basically standard rebar)

It's a new thing in the consumer space but older boards as far back as amd zen1 and intel 10th gen (and unnofficially some intel 9th/8th gen boards even) support it, nothing wrong with a new gpu requiring it, hardware is always moving forward and there are other choices if you don't want to update your older platform right now.

It's obvious Intel designed things differently so there's a big performance hit with/without rebar but I think a more interesting question is what the fuck is AMD and nvidia doing (or rather not doing) that ReBar hardly matters? It's supposed to offer a performance advantage (probably not huge like with Intel, but clearly meaningfull), why doesn't it?

tats what im saying - instead of testing all these games for implementation optimizatuions with the old pcie 256MB window path, they seem to be half-assing this, and just using generic code with every game out there.

So yeah, the massive difference in performance Intel sees compared to NVIDIA or AMD is entirely self-inflicted (entirely due to their poor driver testing.)

 

[trsttte]

tats what im saying - instead of testing all these games for implementation optimizatuions with the old pcie 256MB window path, they seem to be half-assing this, and just using generic code with every game out there.

So yeah, the massive difference in performance Intel sees compared to NVIDIA or AMD is entirely self-inflicted (entirely due to their poor driver testing.)

No, Intel designed their memory controller differently, it's not just a bad optiomization job, it's they designed things with rebar in mind (at least that's the message, I'm not a gpu/silicon architect obviously)

Rebar as a technology is an obvious advantage vs not having it so I don't see any reason to see the cards requiring it as a negative, yeah new gpu requires new technology big whoop, I see it the same way as when we moved from vga/dvi to dp and hdmi, it's progress and a non issue imo.

All their optimization woes are a separate thing.

 

[Jimmy_]

if ReBAR disable, its jus a shit PCB with 2 Fans for display output worse than ~900/800 series cards

 

[HenrySomeone]

Interesting. A bit of a pity, actually, as many of the people looking at these would be those on a considerably low budget, possibly without a ReBAR capable machine.

Not nearly as much of an issue as some would like to make it seem. It's available on Coffee Lake and Zen2; Zen(+) cpus are simply to slow for 3060 class cards anyway.

 

[trsttte]

Zen(+) cpus are simply to slow for 3060 class cards anyway.

That's not true but regardless unless your motherboard manufacturer sucks they also support rebar

 

[HenrySomeone]

They might be okay at 4k, but if rebar can work on those also (haven't delved that deep recently, it used to be undoable), then it's a non-issue anyway.