News Workaround helps improve gaming performance on outdated Intel CPUs — Resizable Bar UEFI mod works with CPUs as old as Sandy Bridge

[Admin]

A modder on GitHub has published a mod that can enable the Resizable Bar on "unsupported" motherboards by modifying the BIOS/UEFI on the motherboard.

Workaround helps improve gaming performance on outdated Intel CPUs — Resizable Bar UEFI mod works with CPUs as old as Sandy Bridge : Read more

 

[bit_user]

on the flip side, it can also degrade performance.

Can anyone explain this?

Does it only apply to older titles that might've had specific optimizations based on a smaller BAR size?

 

[ezst036]

It's things like this that make me really wish open source BIOSes had more traction.

 

[fball922]

Can anyone explain this?

Does it only apply to older titles that might've had specific optimizations based on a smaller BAR size?

My guess is you're defining the data package size per package, so if your game is sending smaller packages down the line, you're waisting the rest of that "spot" on the conveyor belt. Games optimized to send smaller chunks of data at a time (or can't scale) will be less efficient.

 

[bit_user]

My guess is ...

Thanks, but I was hoping someone might be more familiar with the details.

Nvidia describes it like this:

"With the ever-growing size of modern game assets, this results in a lot of transfers. Using Resizable BAR, assets can instead be requested as-needed and sent in full, so the CPU can efficiently access the entire frame buffer. And if multiple requests are made, transfers can occur concurrently, rather than queuing."

GeForce RTX 30 Series Performance Accelerates With Resizable BAR Support | GeForce News | NVIDIA

Support available now for all GeForce RTX 30 Series Founders Edition graphics cards, and select GeForce RTX 30 Series laptops.<br/>

www.nvidia.com

Sending assets in full? No queuing? Sounds like a win! I just want to understand why there's a downside, because I'm not seeing it.

Even if a game already "chunks" data to send in multiple transactions, I still don't see why that would perform worse with a larger aperture. Could it be that some games try to reduce the number of transfers by batching assets until they fit the maximum size, which is now larger and means waiting longer to send over the bundles?

Or, maybe the game is trying to send things preemptively, in order to keep the transfer queue full. Now that transfers happen concurrently and there is no queue, that backfires and later transfers slow down earlier ones?

 

[Varsaggo]

My guess is you're defining the data package size per package, so if your game is sending smaller packages down the line, you're waisting the rest of that "spot" on the conveyor belt. Games optimized to send smaller chunks of data at a time (or can't scale) will be less efficient.

Hey got a question I have a Rx 2060 and in my bios it has the option to turn on resizable bar ( Asus Prime X299 Deluxe II Mobo) I just figured it wouldn't work because the driver level support is not there in the rtx2060 from Nvidia or am I mistaken is this a hardware only enable in bios and it should work there eis bo need for software driver support ? What about Auto 4G Decoding setting with resizable bar in the bios ?on or off? What does it exactly do? Ok I noticed I can either set resizable bar to disable or auto so it's was on auto and I don't know how I would tell if it was activated when Windows booted?

 

[bit_user]

I have a Rx 2060 and in my bios it has the option to turn on resizable bar ( Asus Prime X299 Deluxe II Mobo) I just figured it wouldn't work because the driver level support is not there in the rtx2060 from Nvidia or am I mistaken

According to the Nvidia link, in my above post, it seems you need a RTX 3000 or newer.
: (

What about Auto 4G Decoding setting with resizable bar in the bios ?on or off?

If you upgrade your GPU to a model that supports Resizable BAR, then this says you should enable "Above 4G Decoding" (or set it to "auto", if there's no "enabled" option):

https://www.intel.com/content/www/us/en/support/articles/000090831/graphics.html
​

I don't know how I would tell if it was activated when Windows booted?

Good question. I'd imagine there must be some utility program which would tell you, but I don't know.

 

[rluker5]

Can anyone explain this?

Does it only apply to older titles that might've had specific optimizations based on a smaller BAR size?

Some games with Nvidia and Intel get worse performance with Rebar enabled.
It seems to work much better with AMD CPU/GPU pairings. And of course Arc needs it for gaming. Not so much for basic display, but gaming can get really bad without it enabled.

 

[setx]

Can anyone explain this?

Does it only apply to older titles that might've had specific optimizations based on a smaller BAR size?

I have no idea what the author is talking about, but I've seen serious performance degradation in my OpenGL program when BAR was set to cover the whole GPU memory (surprisingly, just increasing it had no negative impact).

It was a driver bug though and was fixed in newer versions after my report.

Given how modern GPU drivers are full of crutches for specific games, I wouldn't be surprised it any significant change like ReBAR could result in performance degradation due to insufficient testing.

 

[thestryker]

Can anyone explain this?

Does it only apply to older titles that might've had specific optimizations based on a smaller BAR size?

I could never figure it out either as it didn't make any sense to me that the performance would be lower. It happened on both company's cards seemingly randomly which people hypothesized was the reason for nvidia whitelisting.

The original coverage from HUB/Techspot and TPU:
https://www.techspot.com/article/2178-amd-smart-access-memory/
https://www.techpowerup.com/review/nvidia-pci-express-resizable-bar-performance-test/

 

[atomicWAR]

Nice to hear. I been pondering turning my old E5 1680V2 on a socket 2011 Rampage III into a emulation rig but also light Windows 10 gaming PC for my nephew. Maybe I'll nice be and throw in my old RTX 2080Ti and he should be able to play even the newest titles at up to 60-90fps.

I benched that setup before it retired last year and it does surprisingly well at 4K. FC6 hit 110 FPS for example at 4K native with some lowered setting but mostly high save ray tracing and a few other ones plus if your willing to scale the image (or DLSS when possible) you can close to max it out for 90ish FPS in most games at 1440P). Kick in some of that new FSR 3 frame gen mod and old PC's can still have a few good years left.

A number of these older but now dirt cheap Sandy/Ivy bridge->Broadwell Xeons are still quite potent with the larger caches vs consumer, paired with the right GPU and uefi mods like this one it will really help your FPS. I already modded my uefi adding a bootable NVMe drive via an angel wings PCIe add in card. Take the 32GB of ram (have 64GB when needed but its only stable at slow DDR3 1600MHZ vs 32GB DDR3 2400MHZ, in gaming at least though the quad channel ram helps. Rendering or video editing its better to run the full 64GB. Regardless this is good news for gamers on a budget or recycling their old rigs for friends and family in need.

 

[bit_user]

Nice to hear. I been pondering turning my old E5 1680V2 on a socket 2011 Rampage III into a emulation rig but also light Windows 10 gaming PC for my nephew. Maybe I'll nice be and throw in my old RTX 2080Ti and he should be able to play even the newest titles at up to 60-90fps.

Just note what I found about ReBAR requiring RTX 3060 or newer. ReBAR being the whole point of the article, after all...

A number of these older but now dirt cheap Sandy/Ivy bridge->Broadwell Xeons are still quite potent with the larger caches vs consumer, paired with the right GPU and uefi mods like this one it will really help your FPS.

Back then, I bought a Sandybridge E5 Xeon, with quad-channel memory. I cheaped out and went for the quad core version. I then saw someone (Anandtech?) benchmark it against the i7-2700K and they found the HEDT Sandbridge wasn't really faster at anything they tested. I think you'd need a memory-intensive workload, for it to really pull ahead.

Not that it's a bad machine, but the main advantage of those E5 Xeons (and HEDT siblings) was more cores & more PCIe lanes. Also, it had PCIe 3.0, back when the desktop version of Sandybridge was stuck at PCIe 2.0. That really gave it a bit more life, for me.

 

[TerryLaze]

Thanks, but I was hoping someone might be more familiar with the details.

Nvidia describes it like this:

​

"With the ever-growing size of modern game assets, this results in a lot of transfers. Using Resizable BAR, assets can instead be requested as-needed and sent in full, so the CPU can efficiently access the entire frame buffer. And if multiple requests are made, transfers can occur concurrently, rather than queuing."​

​

GeForce RTX 30 Series Performance Accelerates With Resizable BAR Support | GeForce News | NVIDIA

Support available now for all GeForce RTX 30 Series Founders Edition graphics cards, and select GeForce RTX 30 Series laptops.<br/>

www.nvidia.com

​

Sending assets in full? No queuing? Sounds like a win! I just want to understand why there's a downside, because I'm not seeing it.

Even if a game already "chunks" data to send in multiple transactions, I still don't see why that would perform worse with a larger aperture. Could it be that some games try to reduce the number of transfers by batching assets until they fit the maximum size, which is now larger and means waiting longer to send over the bundles?

Or, maybe the game is trying to send things preemptively, in order to keep the transfer queue full. Now that transfers happen concurrently and there is no queue, that backfires and later transfers slow down earlier ones?

ALL the games are made for consoles.
Most of which with a specific data rate for the consoles reading from blueray, so if you increase the rebar you are just wasting resources and wasted resources can lower your performance.

Whenever the first games come out that are made for the nvme drive of the new consoles rebar will only have benefits on those.

 

[atomicWAR]

Just note what I found about ReBAR requiring RTX 3060 or newer. ReBAR being the whole point of the article, after all...

Bummer, I missed that until you brought up. I wrongly assumed the RTX 2000 series was included with rebar support. Thanks did a little sleuthing confirming as such. Though I had little doubt you were correct. You usually are on point with things like this.

Not that it's a bad machine, but the main advantage of those E5 Xeons (and HEDT siblings) was more cores & more PCIe lanes. Also, it had PCIe 3.0, back when the desktop version of Sandybridge was stuck at PCIe 2.0. That really gave it a bit more life, for me.

Yeah I started with a 3930K and grabbed a E5 1680VS for a higher overclock and two more cores for under a hundred dollars back when Zen 1 launched giving me similar IPC to a 1700X in games (and other workloads). Having PCIe 3.0 and quad channel ram is a big reason these old chips can perform when properly configured with a decent GPU and overclock. I mean we can't expect miracles but playable frame rates in most games is certainly doable.

I don't know if they fixed the driver issues with RTX 3000 series and newer cards on older cpus, I lost track, but at one point they had issues of to much driver overhead for a decent experience on those older CPUs but the 2000 series was/is good as were many AMD cards. But honestly a RTX 2080Ti or AMD equivalent is likely as much horse power as I would try to push in that old CPU and assuming 1440P->4K (ish) experience. Anything more is a likely waste of GPU power that is bottlenecked away or I'd assume as much at least. Makes me want to plop my 4090 in it to see how bottlenecked it be at 4K and how much power that E5 1680V2 can actually take before folding....twiddles thumbs....I might try that we'll see. I'll let you know if I do.

I then saw someone (Anandtech?) benchmark it against the i7-2700K and they found the HEDT Sandbridge wasn't really faster at anything they tested. I think you'd need a memory-intensive workload, for it to really pull ahead.

That's about right IME. You typically get a slightly higher FPS from those larger caches Xeons have in SOME newer games but the quad channel memory does a lot of the heavy lifting giving you similar bandwidth to a dual channel DDR4 setup, so save cache sensitive games or workloads...they don't have that much more umph compared to similar core count consumer chips. I actually checked the performance bump by turning off two cores and comparing it to a 4930K and my 3930K (same clocks) in gaming/rendering, finding I typically got another 3-5% in cache hungry games/programs compared to a 4930K and almost double the gains (6-10%) vs the 3930K. A nice bump worth utilizing if you can but not exactly something to write home about either.

 

[bit_user]

ALL the games are made for consoles.

I'm not sure how true that is, given that there are consulting firms which specialize in console ports, so the original developers don't have to be bothered with it.

Most of which with a specific data rate for the consoles reading from blueray, so if you increase the rebar you are just wasting resources and wasted resources can lower your performance.

That's pretty absurd, considering games run off the SSD (or HDD, in prior generations). Bluray is basically just installation media and acts as a license key (assuming you didn't just buy it online).

What's even more bizarre about your claims is that consoles are unified memory. So, there's basically no need for the CPU to ship assets over PCIe since the GPU can access them in-place.

Whenever the first games come out that are made for the nvme drive of the new consoles rebar will only have benefits on those.

ReBAR has nothing to do with storage. Assets can be sitting in a PC's memory and selectively sent to the GPU, as needed.

Again, you're way off base, claiming ReBAR doesn't have benefits today, or when it first came out. Especially on Intel Alchemist GPUs, as mentioned in the article.

 

[bit_user]

Bummer, I missed that until you brought up. I wrongly assumed the RTX 2000 series was included with rebar support. Thanks did a little sleuthing confirming as such. Though I had little doubt you were correct. You usually are on point with things like this.

I'm glad you double-checked, because my only source on that was the Nvidia link.

Makes me want to plop my 4090 in it to see how bottlenecked it be at 4K and how much power that E5 1680V2 can actually take before folding....twiddles thumbs....I might try that we'll see. I'll let you know if I do.

Sure, but don't go out of your way for my sake. I think drivers might have optimizations for AVX2, which means they might really want (if not need) a Haswell or newer.

At work, a 6-core Broadwell E5 Xeon served me well, but my current i9-12900 is way faster, even in spite of how Dell castrated it in their mini-PC form factor. The best thing about the Xeon workstation was being able to install a Titan V, when we used to train AI models in-house.

 

[Lamarr the Strelok]

I have a haswell that is 1 year newer than the SB cpu in the first photo. It also looks like AMD's Adrenaline software also running. I have a rx 570 running adrenaline and a 4770 can this some how help my rig?

 

[bit_user]

I have a rx 570 running adrenaline and a 4770 can this some how help my rig?

The article said you need at least a RX 5000-series (RDNA 1) GPU, to utilize ReBAR/SAM. Of course, I don't know enough to say it's impossible with older GPUs, but you should do your own searching to confirm.

 

[Lamarr the Strelok]

Ah thanks bit user. i obviously missed that in the article. My reading skills are wanting .

 

[dosmastr]

K so how then?

 

[dosmastr]

Bro this is from 2021

 

[Koekieezz]

This is old screenshot of mine, yes it does work, and yes it does give some perf increase, but not all of the game does like resizable bar. But hey, it works (this is an old screenshot during 23.9.3 driver days).

 

[Koekieezz]

I have a haswell that is 1 year newer than the SB cpu in the first photo. It also looks like AMD's Adrenaline software also running. I have a rx 570 running adrenaline and a 4770 can this some how help my rig?

Only possible on Z97/H97 for haswell, as the 8x chipset doesnt have "Above 4g Decoding" toggle inside the bios itself (yes this has been a talk with xCuri0). any Z97/H97 except gigabyte (gigabyte 9x chipset doesnt have above 4g decoding inside the bios) ones could use rebar.. but maxxed at 8GiB if you have 32GiB of ram due to some leftover codes from ivy bridge era that prevents the bar able to use full range at 39 Bit Physical address. Also you need 8GiB of polaris card to actually make the rebar works like normal, 4GiB works but only at 2GiB bar size, doing 4GiB bar size with 4GiB gcn cards tends to crash and make the system unstable, something that is at amd driver side and never went fixed.

 

[Koekieezz]

Hey got a question I have a Rx 2060 and in my bios it has the option to turn on resizable bar ( Asus Prime X299 Deluxe II Mobo) I just figured it wouldn't work because the driver level support is not there in the rtx2060 from Nvidia or am I mistaken is this a hardware only enable in bios and it should work there eis bo need for software driver support ? What about Auto 4G Decoding setting with resizable bar in the bios ?on or off? What does it exactly do? Ok I noticed I can either set resizable bar to disable or auto so it's was on auto and I don't know how I would tell if it was activated when Windows booted?

You could do rebar with turing, BUT it took some time to figure it out, read this (a fork of RebarUEFI)