Intel Arc B390 Xe3 Graphics Benchmarked on Linux: Panther Lake Performance Deep Dive

Intel's Panther Lake processors bring the next-generation Xe3 graphics architecture to Linux users, with the flagship Core Ultra X7 358H featuring Arc B390 Graphics sporting 12 Xe cores clocked up to 2.5GHz. Following our CPU-focused Panther Lake review, we've conducted extensive Linux testing to evaluate the GPU capabilities under real-world conditions.

Hardware and Software Requirements

For optimal Panther Lake graphics support, Linux 6.18+ and Mesa 25.3+ are required, though our testing utilized Linux 6.19 and Mesa 26.0-devel for cutting-edge features. The MSI Prestige 14 test platform requires recent linux-firmware packages containing Intel GuC firmware for Xe3 support. Display capabilities include eDP 1.5, DP 2.1, and HDMI 2.1 with 8K@60 output across four simultaneous displays.

Power Profile Challenges

Initial benchmarking revealed perplexing results: Arc B390 showed minimal performance gains over Lunar Lake's Xe2 graphics. Investigation uncovered significant power delivery differences between Windows and Linux defaults:

• MSI's "balanced" mode defaults to 15W min / 30W max PL1 power limits
• Intel recommends higher OEM power minimums for balanced mode
• Windows/Linux balanced modes exhibit up to 15W TDP differences
• Performance gap violates Intel Evo platform certification expectations

Performance Optimization

To achieve representative performance, Intel recommended:

1. Switching to "performance" platform profile
2. Applying Thermald workaround
3. Installing Low Power Mode Daemon (LPMD) This configuration finally unleashed Xe3's potential, though it complicates out-of-box Linux experiences.

Benchmark Methodology

Tested configurations:

System	Processor	Configuration
ASUS Zenbook S16	Ryzen AI 9 HX 370 Strix Point	Balanced
Lenovo ThinkPad X1 Carbon G13	Core Ultra 7 258V Lunar Lake	Balanced
Acer Swift 14	Core Ultra 7 155H Meteor Lake	Balanced
MSI Prestige 14	Core Ultra X7 358H Panther Lake	Performance+LPMD

All systems benchmarked with identical Mesa 26.0-devel/RADV stack and Linux 6.19 kernel.

Performance Analysis

Gaming Benchmarks (1080p Medium):

• Counter-Strike 2: Panther Lake delivered 86 fps vs Lunar Lake's 72 fps
• Cyberpunk 2077: 38 fps (B390) vs 29 fps (Lunar Lake)
• HITMAN 3: 54 fps (B390) vs 45 fps (Lunar Lake)

Synthetic Tests:

• 3DMark Wild Life: Panther Lake scored 14,650 points
• GravityMark: 45 fps (B390) at 1080p
• Vulkan Ray Tracing (Q2RTX): 28 fps at 1080p

AI Workloads (Llama.cpp Vulkan):

• Panther Lake processed 4.8 tokens/sec vs Lunar Lake's 3.9 tokens/sec

Power consumption during gaming peaked at 42W for the GPU package, with notable thermal headroom observed during sustained loads.

Linux-Specific Observations

• Vulkan ray tracing performance improved 22% over Lunar Lake
• RADV driver optimizations showed significant gains in recent months
• Memory bandwidth limitations visible in texture-heavy workloads
• OpenCL support remains weaker than Vulkan implementation

Build Recommendations

For Panther Lake Linux users:

1. Always enable "performance" power profile
2. Install Thermald and LPMD from distribution repositories
3. Maintain kernel >=6.19 and Mesa >=26.0
4. Verify linux-firmware >=20240610 for GuC firmware
5. Monitor GPU clock scaling with intel_gpu_top

Conclusion

Intel's Xe3 architecture shows tangible generational gains when properly configured, delivering 18-31% performance uplifts over Lunar Lake in GPU-limited scenarios. However, OEM power profile implementations significantly impact real-world performance, particularly on Linux where platform defaults differ from Windows. The Arc B390 establishes Panther Lake as a competitive mobile Linux platform for 1080p gaming and GPU-accelerated workloads when optimized correctly.

Additional Resources:

• Panther Lake Xe3 Architecture Deep Dive
• Linux GPU Driver Installation Guide
• Mesa 26.0 Release Notes