购买新显卡是拥有游戏或其他高性能 PC 的一大乐趣。您可以使用您当前拥有的计算机，并以整机成本的一小部分将其升级到当前的图形标准。
不幸的是，尽管GPU是游戏性能的关键组成部分，但它并不能单独工作。它依赖于计算机中的其他组件来正确完成它们的工作，否则它无法充分发挥其潜力。这被称为“瓶颈”，是购买新GPU时的关键考虑因素。您的GPU(GPU)和现有CPU之间的瓶颈尤其是一个重要问题。
幸运的是，有一些在线工具旨在帮助您检测瓶颈并以此为基础做出决定。具体来说，我们将着眼于gpucheck.com上的一个综合工具。
在深入了解确定现有CPU(CPU)和预期GPU之间是否存在瓶颈所涉及的实际步骤之前，我们需要简要了解一下实际的瓶颈是什么。
究竟什么是 GPU-CPU瓶颈(Bottleneck Exactly)？
当您玩视频游戏时，计算机的每个组件都在处理整个系统的某个方面。您的 CPU 通常负责进行物理计算，为游戏 AI 进行思考，运行游戏逻辑，管理动画等等。您的 GPU 渲染您看到的所有视觉效果，包括所有几何线框、围绕它们的纹理、照明和阴影。
显然，如果CPU没有完成它需要的计算，GPU就无法渲染给定的游戏帧。如果你的角色向地精的头部扔了一把刀，如果CPU没有告诉它是否击中了目标， GPU就无法渲染效果！
反之亦然。如果CPU完成了计算，但GPU还没有完成前一帧的渲染，CPU必须等待它，甚至可能因为它不再相关而转储工作。
在一个组件在继续自己的工作之前等待另一个组件完成其工作的情况下，您就会遇到瓶颈。基本上(Basically)，整个系统的速度仅与链中最慢的组件一样快。在视频游戏中，这通常表现为受较慢组件限制的帧速率。
瓶颈普遍存在吗？
不！事实上，任何系统中几乎总是(always )存在瓶颈。任何一台计算机在任何情况下都能完美平衡，每个组件都在其全部潜力下嗡嗡作响，这是非常罕见的。所以问题真的不在于是否存在某种瓶颈，而在于较慢的组件限制事物的程度是否是一个问题。
如果您的CPU只能让您获得GPU(GPUs)最大性能的 98% 或 99%，那几乎不是问题。如果您因为CPU速度慢而只能发挥 GPU 的 70% 的潜力，那么您就已经在硬件性能上浪费了金钱，如果不进行另一次升级就无法访问。
如果您的新GPU提供 100%，但您的CPU只有 50% 繁忙，这意味着您可以连接更快的卡并享受更好的性能。虽然，这种情况不是什么大问题，因为我们通常将计算机用于玩电子游戏以外的任务。
因此，对于其他应用程序，您仍然可以享受空闲CPU容量带来的好处。更不用说在不影响游戏性能的情况下有一些空间来运行额外的后台任务。简而言之——GPU瓶颈好，CPU瓶颈不好。
影响瓶颈解释的(Affect Bottleneck Interpretation)其他因素
解释瓶颈严重性不仅仅是说GPU X和CPU Y不匹配。这是因为不同类型的软件在任一组件上呈现不同的负载。
仅少量使用CPU功能的游戏将使您的GPU以它可以管理的任何帧速率飞行。另一方面，加载 CPU 密集型模拟或策略游戏，突然间，您通常未充分利用的CPU反而(Load)降低(CPU)了(CPU)帧速率。
您用于播放的设置也会影响此计算。例如，以更高的分辨率播放会给GPU带来更大的压力，使其速度变慢，因为处理更高的像素数需要更长的时间。分辨率越高，CPU的瓶颈就越少。
因为它仍在做同样的工作，但GPU做得更多。因此，如果您的CPU在以 1080p 播放时将帧速率限制为每秒 60 帧，那么您在 1440p 或 4K 时仍将获得 60fps，前提是您的GPU可以满足要求。
使用GPU 检查(GPU Check)检查瓶颈(Bottlenecks)
现在我们已经完成了序言，让我们实际进行一次虚拟瓶颈检查。
- 首先，在 GPU Check 导航到此页面(this page)。现在，在第一个组合(first combination)下，选择您当前拥有的GPU以及您当前拥有的CPU。
- 在所需的质量设置下(desired quality setting)，我们将把它留在Ultra下，因为这是我们想要在游戏中使用的设置。如果您的目标是更低的，请相应地进行调整。
- 现在在第二个组合下，选择你打算购买的GPU 。最后，点击使用相同的处理器(use same processor)。
让我们看看结果并解释它们。这里最重要的数字是CPU Impact on FPS。这显示了CPU对(CPU)GPU的阻碍程度。对于旧卡，这个数字是 10%，这被认为是可以的，尽管它最好应该更少。
新卡held back 20% by the CPU.这意味着我们可能最好购买速度稍慢的卡，超频我们现有的CPU或稍后升级CPU 。
当然，实际上这款新GPU比我们当前的组合高出 36% 到 39%。整体组合(Overall Combination)得分向我们展示了它作为超设置下的绝对性能组合有多好。
使用此信息，您应该能够就该潜在GPU是否适合您做出明智的选择。
See How Much Your CPU Bottlenecks Your GPU BEFORE You Buy It
Buying a new graphics cаrd is оne of the grеat joyѕ of owning a gаming or other high-performance PC. You get to take a computer you currently own and, for a fraction of a whоle machine’s cost, upgrade it to current graphical standards.
Unfortunately, despite being a key component to gaming performance, your GPU doesn’t work in isolation. It depends on the other components within the computer to do their jobs properly, or it can’t reach its full potential. This is known as “bottlenecking” and is a key consideration when buying a new GPU. A bottleneck between your GPU and existing CPU in particular is an important concern.
Luckily there are a few online tools designed to help you detect bottlenecks and base your decision on that. Specifically, we’ll be looking at a comprehensive tool found at gpucheck.com.
Before digging into the actual steps involved in determining whether a bottleneck exists between your existing CPU and prospective GPU, we need to briefly unpack what a bottleneck is in practical terms.
What Is a GPU-CPU Bottleneck Exactly?
When you are playing a video game, every component of your computer is working on some aspect of the overall system. Your CPU is generally responsible for doing physics calculations, it does the thinking for the game AI, runs the game logic, manages animation and so on. Your GPU renders all the visuals that you see, which includes all the geometric wireframes, the textures wrapped around them, lighting and shadows.
Clearly the GPU can’t render a given frame of the game if the CPU hasn’t finished the calculations it needs. If your character has thrown a knife at a goblin’s head, the GPU can’t render the impact if the CPU hasn’t told it whether the knife hit the target!
The reverse is also true. If the CPU is done doing its calculations, but the GPU isn’t finished rendering the previous frame, the CPU has to wait for it, perhaps even dumping the work because it’s no longer relevant.
In a situation where one component is waiting for another to finish its job before moving on with its own work, you have a bottleneck. Basically, the entire system is only as fast as the slowest component in the chain. In video games this generally manifests as a frame rate limited by the slower component.
Are Bottlenecks Universally Bad?
No! In fact, there is almost always a bottleneck in any system. It’s incredibly rare for any computer to be perfectly balanced in every situation, with each component humming along at its full potential. So the issue really isn’t whether some sort of bottleneck exists, but rather whether the degree to which the slower components limit things is a problem.
If your CPU only lets you get the benefit of 98% or 99% of your GPUs maximum performance, that’s hardly an issue. If you’re only getting 70% of your GPU’s potential because of a slow CPU, you’ve wasted money on hardware performance you can’t access without yet another upgrade.
If your new GPU is giving 100%, but your CPU is only 50% busy, it means you could have hooked up a faster card and enjoyed even better performance. Although, this situation is less of an issue, given that we usually use our computers for tasks other than just playing video games.
So for other applications you’ll still enjoy the benefit of that spare CPU capacity. Not to mention having some room to run additional background tasks without affecting game performance. In short – GPU bottleneck good, CPU bottleneck bad.
Additional Factors That Affect Bottleneck Interpretation
There’s more to interpreting bottleneck severity than just saying GPU X and CPU Y are a bad match. That’s because different types of software present different loads on either component.
A game that makes only light use of CPU functions will let your GPU fly at whatever frame rate it can manage. Load up a CPU-intensive simulation or strategy game on the other hand, and suddenly your usually under-utilized CPU is tanking the frame rate instead.
The settings you use to play also influence this calculation. For example, playing at higher resolutions puts more strain on the GPU, slowing it down because it takes longer to crunch higher pixel counts. The higher the resolution, the less of a bottleneck the CPU becomes.
Because it is still doing the same work, but the GPU is doing more. So if your CPU is limiting frame rates to 60 frames per second when playing at 1080p you’ll still get 60fps at 1440p or 4K, assuming your GPU is up to it.
Checking For Bottlenecks With GPU Check
Now that we have the preamble out of the way, let’s actually do a virtual bottlenecking check.
- First, navigate to this page at GPU Check. Now, under first combination, choose the GPU you currently have as well as the CPU you currently have.
- Under desired quality setting, we are going to leave this under ultra, since that’s what setting we want to use in games. If you are aiming for something lower, adjust accordingly.
- Now under the second combination, choose the GPU you intend to buy. Finally, click use same processor.
Let’s look at the results and interpret them. The most important number here is CPU Impact on FPS. This shows how much the CPU is holding back the GPU. With the old card, this figure was 10%, which is considered OK although it should preferably be less.
The new card is held back 20% by the CPU. Which means we are probably better off buying a slightly slower card, overclocking our existing CPU or upgrading the CPU at a later date.
Of course, in real terms this new GPU is between 36% and 39% than our current combination. The Overall Combination score shows us how good this is as an absolute performance combo at ultra settings.
Using this information, you should be in a position to make an informed choice about whether that prospective GPU is the right purchase for you.
