本機 AI 記憶體餘量
可免費查看，更改需要 Pro
在你下載或載入本機模型之前，先檢查它能否放進你 Mac 的記憶體。
The problem
Downloading a local model is a long wait, and the failure comes at the end: it will not load, or it loads and your Mac starts swapping. The size on the download page is only part of the answer, because the context length you choose adds memory too.
Local AI headroom answers the question first. You pick the model size and context. Hedroom estimates what it needs, compares that with what your Mac can give a model right now, and names the line that decided the answer.
How it works
- Pick. Choose a model family and size, 4-, 8- or 16-bit, and a context from 4K to 128K. Hedroom names families and sizes only; it recommends no product.
- Estimate. It adds up the weights, the context cache (which grows with the context) and runtime overhead, each shown as "about". A 15% margin covers the fact that layer and head counts are typical for a family, not read from your file.
- Compare. The total is checked against the GPU memory limit and against what is free right now (free memory plus cached files; compressed memory does not count).
- Answer. Fits, Tight, Make room or Won't fit, with the line that decided it.
- Act, if you choose. Make room lists apps to relaunch or quit through the normal safety checks. On some Macs, Hedroom can raise the GPU limit until you restart, after a confirmation.
What you will see
A big verdict, "Fits.", "Tight.", "Fits, after making room." or "Won't fit.", with a sentence naming the line that decided it and the parts of the estimate: "Weights about … · context about … · runtime about … The estimate can be off by about 15%." A gauge shows what the model needs against two markers: what the GPU can use and what is free right now.
Beside it sits the GPU memory limit control, with a warning always on screen (less memory for macOS, your Mac can slow down or become unstable, it lasts until you restart), and a list of model apps Hedroom finds running: Ollama, LM Studio, Jan and GPT4All, with what they use. On a 16 GB Mac the limit control is off and says why.
A worked example
Example, not real data
A mid-size model on a 16 GB Mac
Say you want to try a Llama-family model at 8B parameters, 4-bit, with an 8K context. Hedroom estimates weights of about 4.8 GB, context of about 1.1 GB and runtime of about 0.8 GB: about 6.7 GB, or about 7.7 GB with the margin.
macOS lets the GPU use about two-thirds of a 16 GB Mac's memory by default, around 10.7 GB, so the GPU limit is not the problem. But say Chrome and Slack are open and free memory plus cached files reads about 7 GB. The low estimate fits and the high one does not, so the verdict is Tight, and the Make room list shows which apps hold the most. Hedroom promises no speed: it estimates memory only.
Details and limits
它做什麼
- 你選擇模型系列和大小、4、8 或 16 位，以及從 4K 到 128K 的上下文長度。
- 估算它所需的記憶體（權重、上下文快取和執行時），然後與 GPU 可使用的記憶體以及現在的可用記憶體進行比較。
- 給出「放得下」「緊張」「騰出空間」或「放不下」的答案，並附上決定結果的那一行。
- 「騰出空間」會建議透過 Hedroom 的常規操作，重新開啟或結束佔用記憶體的 App。
- 在 Ollama、LM Studio、Jan 和 GPT4All 執行時留意到它們，並說明它們佔用多少。
- 可以在你確認之後，把 GPU 記憶體上限調高到你重新啟動為止，確認中會說明留給 macOS 的記憶體有多少。
What it will not do
- 下載、載入或執行模型，或與模型 App 對話。
- 承諾速度。它只估算記憶體。
- 提供會讓 macOS 剩下不到 8 GB 的上限。
- 未經你確認就調高上限。Hedroom 結束時會把上限恢復成原來的值，除非你期間自己改過。
Limits
- 估算可能有約 15% 的誤差。層數和注意力頭數是某個模型系列的典型值，不是從你的檔案中讀取的。
- macOS 沒有公佈它預設的 GPU 上限。Hedroom 顯示的是它自己的判斷：不超過 36 GB 的記憶體取三分之二，超過的部分取四分之三。
- 在記憶體為 8、16、18 或 24 GB 的 Mac 上，Hedroom 不提供更高的上限，因為它允許的最大值不會超過 macOS 已經給 GPU 的量。
- 調高上限需要與風扇控制相同的輔助工具，需要在「系統設定」中核准。更高的上限會給 macOS 留下更少的記憶體，如果記憶體不足，你的 Mac 可能會變慢或變得不穩定。該設定會保持到你重新啟動為止。
免費還是 Pro
檢查以及讀取 GPU 記憶體上限是免費的。調高上限屬於 Pro。重置永遠不會被鎖定。
Raising the limit changes how your Mac behaves, which is why it is Pro.
Questions people ask
Does Hedroom download or run the model?
No. It never downloads, loads or runs a model, and never talks to a model app. It estimates memory and notices which model apps are running.
How accurate is the estimate?
It can be off by about 15%. The weights come from a simple formula, and layer and head counts are typical for the family, not read from your file. The verdict checks both the estimate and the estimate plus margin, so a borderline case reads Tight rather than Fits.
Is raising the GPU memory limit safe?
It leaves less memory for macOS, and your Mac can slow down or become unstable if memory runs short. Hedroom never offers a limit that leaves macOS less than 8 GB, shows how little is left before you confirm, puts the limit back when it quits, and the setting goes away at restart anyway.
Does it need the helper?
Checking is free and needs no helper. Raising or resetting the limit uses the same helper as fan control, which requires approval in System Settings. Approving the helper has the steps.