Strata 0.2.8: faster Arc B-series pairs and four-card Radeon servers, a Mac DeepSeek memory leak fixed, fewer lost tool calls

The app is 0.2.8. Control and every engine package are 0.1.54.

The numbers first

• Two Intel Arc Pro B65 cards: decode 17% to 23% faster, prompts about 7% to 13% faster. Chat runs at 71 to 74 tokens per second, against 60 to 63 before, and JSON at 80 to 83, against 67 to 68. We tested two Arc Pro B65 32 GB cards with Qwen3.8-Flash-Next IQ3_S, five paired runs, and every pair was faster. The answers are the same as before. This applies to exactly two Arc B-series cards; one card, A-series cards and three or more cards run as before.
• Four Radeon AI PRO R9700 cards serving many requests: 2.4 times the total speed at 32 requests at once (155 to 370 tokens per second in total; at 8 at once, 157 to 261). One request alone runs at the same speed as before (67 tokens per second). Setup and the launcher pick this for exactly four R9700 cards running Qwen3.8 IQ3_S. All 32 answers matched a single-request run, and two soaks (25 and 12 minutes, 1,600 requests) had no errors.
• DeepSeek on the Mac no longer slows down after a few requests. On the Metal engine every request left about 1.3 GB of GPU buffers behind, until the Mac ran short of memory and decode fell from 16 tokens per second to 3. Memory now stays flat at 76 GB over 34 requests, and decode stays at 18 to 22 tokens per second, with the same answers. Tested on an M5 Max with 128 GB, not on a 256 GB Mac Studio.
• Tool calls the model writes slightly wrong now still go through, by default. Over 1,462 agent turns, 98.3% are now read as intended, against 92.9% before. This only applies to tools the request declared.
• RTX cards with 12 GB or less: the 0.2.7 routing speed-up is off again by default. It made answers faster (RTX 3060: story +15%, code +37%), but your reports and our own checks tied it to repeated text in long sessions. With nothing set, the engine now routes exactly as 0.2.6 did. To get the speed back, turn on "Faster answers on 12 GB NVIDIA cards" under Models, Native engine settings, Speed (or run strata launch --set STRATA_ROUTE_PRIOR=1.5).
• DeepSeek no longer stops in the middle of a word. The server ended a reply on pieces such as im, | or >, so "Nerazim" came out as "Neraz" (#4576, #4137). It happened when a DeepSeek server was started from a config that did not name the model family.
• 0.2.8 against 0.2.7.1, five paired runs each. On one RTX A6000 with Qwen IQ3_S, decode went from 105.9 to 111.4 tokens per second on a story and from 139.8 to 145.2 on code; prompts are unchanged (1,927 and 1,924 at 4K, 2,571 and 2,569 at 20K). On one Radeon R9700, decode went from 73.7 to 79.7 on a story and from 106.3 to 107.8 on code; prompts are within 0.4% once the engine is warm. DeepSeek 2.25 decode is 4.3% faster on an RTX A6000, with the same output as 0.2.7.1 on our score check.

What is new

• Arc B-series pairs. The first card starts the next window while the second card is still checking the current one (--pipeline-windows 2), and setup writes --spec 2 for the pair. Turn it off with --pipeline-windows 0; a --spec you set yourself is kept. The Arc engine also reads prompts about 5% faster on B-series cards with a new attention path, and three bugs that stopped --pipeline-windows from running at all are fixed.
• Four-card Radeon profile. For four R9700 cards: 32 request slots in 4 groups, layer split 13,26,39, a prompt chunk of 2048 and three small switches. It only fills in what you have not set. Turn it off with "four_card_profile": false in the config.
• Bigger batch windows on AMD. The HIP engines now check and batch up to 16 rows at once instead of 8, which is what the four-card profile needs. The answers are bit for bit those of the 8-row build on every card we ran (10 of 10 on R9700, RTX PRO 5000, A6000, A4000 and P100). NVIDIA, Intel and Mac builds stay at 8.
• DeepSeek prompt speed, opt-in. DS4_FAT_ROWS (thanks to lyesrock, PR #4366) gives the busiest experts of a long prompt one bigger matrix multiply: +2% to +5% on two RTX A6000. It is off by default, because the gain is under our bar for a default and the output is not bit-exact.
• A clearer message on Arc and older CPUs. A model folder without native_experts.txt is read as the AVX-512 pack, and the engine used to blame the CPU. It now names the real cause, and strata doctor warns before the start.
• One source for the driver floor. Setup now reads the CUDA 12 driver floor from the engine package, so setup and the update agree. The floor itself has not changed: 575.51, or 576.02 on Windows.

Fixed, from your reports

• App:
  • DeepSeek no longer fails to load with picture reading off (#4358, #4359, #4505, #4507). The app now sends DeepSeek only the options it takes, and "GPU memory for other apps" goes out as --reserve-mib (#4504).
  • The wait for a big model to load now follows the model size, as strata launch does (#4191, #3459; thanks to miketgv, PR #3817).
  • "See engine log" no longer points at a log that was never written (#3714).
• Monitor: with a model running, an AMD card on Windows showed load, memory and temperature as "Not available". The Monitor now fills in what the engine does not report, and reads the temperature on Windows AMD cards (#3727). On Linux, a server's remote-console chip no longer shows up as a graphics card.
• Terminal and setup:
  • The update's test start skips DeepSeek configs (#4440; thanks to ai-bits, PR #4267).
  • A saved lower-case model tag such as iq3_xxs is found (#4209, PR #4317).
  • The packaged Terminal runs setup without CMakeLists.txt, and strata install --source modelscope passes its options on (#4188).
• Memory and cache:
  • A 256K start on two cards no longer takes the Strix Halo reserve off the RAM store. On 2x A6000 the RAM store grew from 77.7 to 106.5 GB (#4147).
  • The conversation cache no longer runs short when the PLE table is locked (#4518).
  • Parking an idle --batch slot keeps the shared prefix, so the first token of round 2 takes 0.66 s instead of 3.3 s (#4420).
  • The automatic expert cache leaves the reserve you asked for (#4474).
  • A new engine waits for the old one to give its memory back (#4051).
• Tool calls and the server:
  • An argument that quotes a tool call stays exact (#4078; thanks to Tsury, PR #4132).
  • Damaged arguments, a missing </function> and a stray closing think tag no longer lose the call (#4427, #4077).
• DeepSeek on several cards:
  • A layer split's chunked prompt no longer deadlocks (PR #4211).
  • slot_load() writes each tensor-parallel member's state under its own device (#4350; the single-card fault is still open).
• Mac: the DeepSeek memory leak described above.

Going back to 0.2.7.1

strata components rollback returns to the previous engine. The Qwen route prior and tool-call recovery can both be set the 0.2.7 way: STRATA_ROUTE_PRIOR=1.5 and "tool_call_recovery": false in the model's run config. The 16-row windows are a build option (-DSTRATA_WINDOW_MAX_T=8); there is no switch at run time.

Off unless you turn it on

• DS4_FAT_ROWS=N (DeepSeek, CUDA).
• Everything listed under "Off unless you turn it on" in 0.2.7 is unchanged.

What we did not test

• A 256 GB Mac Studio, or any Mac other than one M5 Max.
• The four-card profile on anything other than four R9700 cards, and 64 slots at long context.
• The Monitor fix on a Windows AMD graphics card. We tested it on Linux AMD cards and on Windows with NVIDIA and an AMD integrated GPU. If you have a Radeon on Windows, please tell us whether the Monitor now shows load, memory and temperature.
• The Windows commit-limit side of #4518, the full #4051 wedge on a host with little RAM, and #4427 on a real model beyond the parser tests.
• Metal and SYCL builds with 16-row windows; they stay at 8 and were only compile-checked.
• The B-series pipeline on anything other than two Arc Pro B65 cards.
• Strix Halo changes are not in this release.

Updating

• App: the in-app update offers 0.2.8, or download the installer below.
• Terminal: run strata update. It fetches Control 0.1.54 and the 0.1.54 engine in the same run, and keeps the old engine for strata components rollback. If your Terminal is older than 0.2.0 (for example 0.1.45.x), run the install line again.
• DeepSeek engine: it updates itself on the next strata launch.
• DGX Spark: run strata update; it reads strata-feed-linux-aarch64.json.
• Mac: the app, the Terminal and the DeepSeek engine are signed and notarized.

Downloads

40 files. Three installers (Windows, Linux AppImage, Mac dmg) and the Mac updater archive Strata.app.tar.gz (0.2.8), with the update signatures for the Windows, Linux and Mac app; the four Control packages (0.1.54: Windows, Linux x86, Mac, Linux ARM64); 14 Qwen engine packages (0.1.54: Windows CUDA 13, CUDA 12 and three AMD packages; Linux CUDA 13, CUDA 12, four AMD packages and Intel SYCL; Mac Metal; Linux ARM64); six DeepSeek engine packages (0.1.54: Windows CUDA 13 and AMD RDNA3, Linux CUDA 13 and AMD rx9070, Mac Metal, Linux ARM64); strata-feed.json and strata-feed-linux-aarch64.json with their signatures; latest.json, install-manifest.txt, install.sh, install.ps1 and SHA256SUMS.txt. The DeepSeek CUDA packages are built for sm_86, sm_89 and sm_120.

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