如果你曾經嘗試過讓一款老式電腦遊戲在現代系統上執行，你可能會對這款遊戲的執行速度感到震驚。為什麼老遊戲在現代硬體上失控了？

今天早些時候，我們向您展示瞭如何在現代計算機上執行舊軟體；今天的問答環節是一個很好的補充，它深入探討了為什麼一些舊軟體（特別是遊戲）在現代硬體上執行時似乎永遠無**常工作。

今天的問答環節是由SuperUser提供的，SuperUser是Stack Exchange的一個分支，是一個由社群驅動的問答網站分組。

問題

超級使用者讀者TreyK想知道為什麼舊電腦遊戲在新硬體上執行得如此之快：

I’ve got a few old programs I pulled off an early 90s-era Windows computer and tried to run them on a relatively modern computer. Interestingly enough, they ran at a blazing fast speed – no, not the 60 frames per second kind of fast, rather the oh-my-god-the-character-is-walking-at-the-speed-of-sound kind of fast. I would press an arrow key and the character’s sprite would zip across the screen much faster than normal. Time progression in the game was happening much faster than it should. There are even programs made to slow down your CPU so that these games are actually playable.

I’ve heard that this is related to the game depending on CPU cycles, or something like that. My questi*** are:

• Why do older games do this, and how did they get away with it?
• How do newer games not do this and run independently of the CPU frequency?

那是怎麼回事？為什麼舊遊戲中的精靈在螢幕上燃燒得如此之快以至於遊戲無法玩？

答案

超級使用者contributor JourneymanGeek將其分解為：

I believe they assumed the system clock would run at a specific rate, and tied in their internal timers to that clock rate. Most of these games probably ran on DOS, and were real mode (with complete, direct hardware access) and assumed you were running a iirc 4.77 MHz system for PCs and whatever standard processor that model ran for other systems like the Amiga.

They also took clever shortcuts based on those assumpti*** including saving a tiny bit of resources by not writing internal timing loops inside the program. They also took up as much processor power as they could – which was a decent idea in the days of slow, often passively cooled chips!

Initially one way to get around differing processor speed was the good old Turbo button (which slowed your system down). Modern applicati*** are in protected mode and the OS tends to manage resources – they wouldn’t allow a DOS application (which is running in NTVDM on a 32-bit system anyway) to use up all of the processor in many cases. In short, OSes have gotten **arter, as have APIs.

Heavily based off this guide on Oldskool PC where logic and memory failed me – it’s a great read, and probably goes more in depth into the “why”.

Stuff like CPUkiller use up as many resources as possible to “slow” down your system, which is inefficient. You’d be better off using DOSBox to manage the clock speed your application sees.

如果你對早期電腦遊戲中的實際程式碼是如何實現的感到好奇（以及為什麼它們對現代系統的適應能力如此之差，而沒有在某種模擬程式中進行沙盒處理），我們還建議在另一個超級使用者答案中檢視這個冗長但有趣的過程分解。

有什麼要補充的解釋嗎？在評論中發出聲音。想從其他精通技術的Stack Exchange使用者那裡瞭解更多答案嗎？在這裡檢視完整的討論主題。