根據prime95程式設計者的FAQ
Will the program run faster if I raise the priority?

No. The operating system does an excellent job of giving all spare CPU cycles to the program. The only thing that raising the priority will do is make your other jobs less responsive.
For example, lets say during the next minute your spreadsheet needs 10 seconds to recalculate. If your spreadsheet is running at a higher priority, then it will take 10 elapsed seconds to display its results. Prime95 will then get the remaining 50 seconds of the minute. If they run at equal priority, then the spreadsheet will get 10 of the next 20 elapsed seconds before it displays its results. Prime95 also gets 10 of the first 20 seconds as well as the remaining 40 seconds. In both cases prime95 got 50 CPU seconds, but in the first case you saw your spreadsheet results faster.
似乎如果機器是idel的且只有在跑prime的情況下，所有的資源都會被用在計算上。
所以應該設1或9在燒機測穩定度上應該沒有太大影響才是...
不過我對軟體程式設計作業系統一竅不通，所以也不知道上面的認識是否正確，
是不是可以解釋一下如果1跟9影響很大的話，依據是在哪邊呢?