Engineering Arc - 8/19/2022

by Lisa Pearce, Vice President and General Manager for the Visual Compute Group

I want to continue to share more information and respond to questions we are receiving from customers, the community, and press. We’ve got 4 hot topics to hit in today’s blog.

Question #1: Why does Intel performance vary between DX11 and DX12 titles?

Tom Petersen and Ryan Shrout did a video walkthrough of this issue here. The crux is that DX11 and older APIs require both Microsoft’s and Intel’s software to do a lot of abstractions that make game development simpler. Makes sense. But this thick layer of software can lead to inefficiencies that require continued refinement to minimize performance losses. DX12 and Vulkan, in contrast, allow game developers and game engine developers to have more control over the low-level GPU hardware. This eliminates layers of complexity and allows the GPU to run closer to its theoretical peak performance for any game.

For DX9 Intel uses a DX9on12 mapping layer which maps graphics commands from DX9 to DX12. We do extensive compatibility and performance testing, and partner closely with Microsoft and ISVs to continuously optimize this solution. We have been shipping this solution since our 12th Gen Intel Core launch in 2021, and we will continue to invest heavily in this technology for both integrated and discrete graphics solutions.

For Arc, if the game you’re playing supports DX12 and DX11 like Shadow of the Tomb Raider and others do…turn on DX12 and see the GPU unleashed. We expect to close the gap on DX11 performance over time though, which will be an upside as we roll out future drivers.

Question #2: What is Resizable BAR (ReBAR) and why is it important to Intel Arc GPUs?

ReBAR is an optional PCI Express feature that controls how much of the GPUs memory can be accessed in one transaction from the CPU. It is supported on most modern motherboards and CPUs. Intel Arc GPUs are optimized to work with larger memory transactions, so having ReBAR on is essential to delivering peak performance in Arc. We are recommending to our motherboard partners that ReBAR be turned on by default moving forward, and we expect future chipsets to continue to support this feature.

TAP and Ryan have a detailed discussion on the value of ReBAR to Arc here. For more details on how to enable ReBAR on your motherboard, check out the quick start guide on Intel.com.

Question #3: I’ve read reviews that say Intel’s driver is not ready yet. What’s the status?

We appreciate the feedback we are getting in early reviews of our Arc software stack. And it has been bumpy. We have received frank feedback from press during recent reviews, and we have taken it to heart. For example, we filed 43 issues with our engineering team from a review of the A380 by Gamers Nexus. We had corrected 4 of those issues by the end of July. Since then, we corrected 21 UI issues in our driver release on August 19th, and it also includes Day0 support for Saints Row, Madden NFL 23, fixes for Stray and Horizon Zero Dawn crashes, Marvel’s Spider-Man performance fix, and fixes on SmoothSync corruptions. We are taking similar approaches with reports from other press reviews.

We are continuing to learn what it will take for us to be successful. Some of the issues were related to our installer and how it downloaded unique components after initial installation. This allows us to have a smaller initial download to get users started quicker. But unexpected failures are causing that process to be unreliable, and later this year we will be moving to a combined package that is downloaded and installed all at once. No more installer issues.

Question #4: Do Intel Arc GPUs support VRR display technologies?

Absolutely!

VRR stands for “Variable Refresh Rate” and refers to a technology that synchronizes a display refresh with the render rate of a GPU. This eliminates tearing and other visual defects. All Arc GPUs support the VESA display standard called “Adaptive Sync.” It’s easy to set up and works on all games. Sometimes monitors will carry a logo saying they support FreeSync or GSYNC-Compatible which are both brands that rename the fundamental Adaptive Sync capability. All three names of Adaptive Sync are supported on Intel Arc GPUs.

Ryan did a fun video showcasing Intel Arc Display support here.

Notices and Disclaimers:

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex

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Your costs and results may vary.

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All product plans and roadmaps are subject to change without notice.

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