LLM Testing Behind the Scenes Unboxing Gigabyte AMD Radeon 7600 XT 16GB ROCm vs Vulkan battle!

Product Reviewed

• GPU: Gigabyte Radeon RX 7600 XT 16GB (“Gaming OC”)
• Purchase context: Bought on sale for ~$299 and used for the channel’s testing (story also mentions money cycled from sold RTX 4060 Ti 16GB units).

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Key Features / Specs Mentioned

• 16GB GDDR6
• 128-bit memory bus
• ~288 GB/s memory bandwidth (as stated)
• ~190W TDP (as stated)
• Card design/size: 3-fan model
  • Described as smaller than a 4090
  • Similar-ish to Intel Arc A770
  • Much smaller than an RTX 4060 Ti (in their comparison lineup)

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Setup + Software / Compatibility Notes (Important Cons)

The reviewer expected ROCm to work out-of-the-box, but found a limitation:

• ROCm supports mainly the 7900 series out of the box
• RX 7600 XT required a workaround
  • Involved a GitHub issue
  • Used an environment variable to effectively make it run in a forced/unsupported ROCm mode (set to 11.0.0 behavior)

Stability / Risk Concerns

Because it’s a newer card while using a backward/forced ROCm mode, they worried about:

• How ROCm driver behavior might behave under forced compatibility
• Whether it would remain compatible with llama.cpp / local AI
• What those components were compiled on

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Testing Approach / Backends Compared

The main technical comparison was:

• ROCm vs Vulkan backends

Test structure

They ran basic benchmark runs (not the full leaderboard initially), using:

• Quantized model (Q8)
• Full FP16

Each configuration was tested over:

• 10 iterations (“10 tests”)

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Performance Results (Tokens/sec)

ROCm Backend

• Q8:

  • Starts around ~27.5 eval tokens/sec
  • Drops significantly across the 10 runs, later citing values “ended up” around roughly ~8.3 / 9.2, with additional readings suggesting it fell through periods (with the key takeaway being a strong downward trend, not a stable plateau)

• FP16:

  • Ends around ~12.14 eval tokens/sec
  • Notes that FP16 slowed down, but less aggressively than Q8

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Vulkan Backend

• Q8:

  • Starts around ~20 eval tokens/sec
  • Shows better overall behavior than ROCm’s Q8 trend
  • Final cited value around ~13.13 eval tokens/sec

• FP16:

  • Starts around ~10.5 eval tokens/sec
  • Ends around ~5.3 eval tokens/sec
  • Described as roughly cutting speed by half by the end of the run series

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Overall Comparison Conclusion (From Plotted Data)

They combine four run sets:

• ROCm Q8
• ROCm FP16
• Vulkan Q8
• Vulkan FP16

Key graph takeaways:

• ROCm + Q8: starts fast but falls off hard (no clear plateau; described as “slowly crawling to a halt”)
• Vulkan + Q8: appears more stable and likely better sustained performance than ROCm Q8
• ROCm FP16 vs Vulkan FP16:
  • ROCm FP16 looks better (stays higher)
  • Vulkan FP16 looks worse (drops steeply toward ~5.3)

Their summary framing:

• “Quantized models look to run quite a bit better through Vulkan”
• “FP16 looks like it runs quite a bit better through ROCm”

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Pros / Cons (As Shown in the Video)

Pros

• ROCm can work, but only via a workaround
• Performance potential is decent for a ~$300 card (not “world-beating,” but “decent results”)
• Vulkan shows a more favorable performance profile for Q8 (better sustained behavior)

Cons

• ROCm not officially supported out of the box for the 7600 XT (extra steps required)
• ROCm Q8 performance declines heavily over time (no plateau observed in their run length)
• Vulkan FP16 performance appears very weak vs ROCm FP16

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User Experience / Workflow Notes

They emphasize that significant behind-the-scenes work was required to:

• Get the testing platform working per card/backend
• Extract metrics
• Ensure backend compatibility (they mention earlier struggles with Intel Arc A770)

They also encourage viewers to suggest tuning ideas:

• “retest” if people propose improvements for ROCm/Vulkan on this card

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Verdict / Recommendation

Backend choice by model type

• For Q8 (quantized): choose Vulkan
• For FP16: choose ROCm

Next step not finalized

They haven’t finalized which backend to use for the full “Mistral leaderboard tests”, based on the trends shown—they ask viewers for guidance.

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Unique Points Mentioned (Consolidated)

1. Unboxing + physical comparison: 3-fan, size relative to 4090 / Arc A770 / RTX 4060 Ti
2. Purchase rationale: bought on sale for ~$299; money cycled from sold 4060 Ti 16GB
3. ROCm expectation vs reality: only 7900-series supported out of the box
4. ROCm workaround: GitHub issue + environment variable to force compatibility behavior
5. Risk concerns: unsupported ROCm mode + newer GPU + driver/compiler assumptions
6. Main experiment: ROCm vs Vulkan on RX 7600 XT 16GB
7. Test run types: Q8 (10 runs) and FP16 (10 runs)
8. ROCm Q8 trend: starts ~27.5 eval tok/s, falls to about ~9.2
9. ROCm FP16: ends around ~12.14 eval tok/s (declines, but less than Q8)
10. Vulkan Q8: starts around ~20 eval tok/s, ends about ~13.13
11. Vulkan FP16: starts around ~10.5 eval tok/s, ends about ~5.3
12. Graph interpretation: ROCm Q8 shows no plateau; performance “crawls down”
13. Final guidance: Vulkan for Q8, ROCm for FP16
14. They may revisit Intel cards later due to backend behavior differences

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Speaker Views

• Single primary speaker: handled unboxing, testing setup, ROCm/Vulkan comparison, and graph-based conclusions
• No separate speakers were indicated in the subtitles