《巫師2：王國刺客》N卡最新驅動程式(275.27 beta)，在SLI模式下，設定最高畫質和提高效能的方法。

kevinnium

國外超頻網站研究出的替代方案：
http://www.overclock.net/pc-games/1021185-witcher-2-sli-fix-guide.html

官方說法是這樣的：
If you have an SLI setup, disable SLI and start the game. It will resolve most of the performance issues since SLI support is non existent.
如果你是使用SLI設定，必須要先取消再進入遊戲。絕大部分效能低下的問題就能夠解決，因為目前SLI還不支援這款遊戲。
目前使用SLI模式玩巫師2的玩家，應該會發現進入遊戲後效能低下，有開跟沒開是一樣的。

玩家說法是這樣的：
如果不怕麻煩，堅持要使用SLI模式來玩巫師2的話，其實透過手動設定是可以實現的，在N卡下一個正式版驅動程式還沒出來前，給有雙卡的同學嘗鮮：

What is this fix?
This is a Nvidia Inspector tweak that makes SLI work in Witcher 2. Currently it doesn't. After this fix you should see noticeable FPS improvements w/SLI. For example, with SLI GTX 580s you'll see a considerable gain in FPS at Ultra Spec w/UberSampling enabled. That said, there may still be more room for improvement down the road in official driver/game updates.

Problems
None to my knowledge, however I've only tested this fix for my GTX 580 TRI SLI; if this fix doesn't work for your other cards then maybe it's card specific? If you somehow mess up in Nvidia Inspector, at worse you may need to reinstall your Nvidia drivers.

I've heard of a "light leaking" bug with SLI, that is possibly fixed by forcing AFR2 (Alternate Frame Rendering 2) for The Witcher 2 (either through Nvidia Inspector or the Nvidia Control Panel). I haven't seen that bug yet.

Prerequisites
This fix has been tested to work for Nvidia drivers 270.61 (stable) and 275.27 (beta). There is no FPS improvement between the two after much testing. The beta drivers however have improved 3D Vision compatibility for The Witcher 2, and maybe other non-documented tweaks.

Instructions
1. Download and install Nvidia Inspector. (latest version to my knowledge is 1.9.5.5)
2. Open Nvidia Inspector. Click on the tool button at the right of the "Driver Version" box. This opens up the Profile Settings editor.
3. In the "Profiles" drop-down select "The Witcher 2". Under "Compatibility" (first section) look for "SLI compatibility bits". You want to change this field's value from whatever it is to 0x02C04205.
4. Hit "Apply Changes". You're done! There's no need to change anything else.


簡單說明一下(圖片因為檔案太大，已經縮小過尺寸和壓縮格式。)：
1. 先去3D專業網站(Geeks3D)下載 Nvidia Inspector 。

2. 用管理者權限安裝軟體後，打開Inspector，選擇"Driver Version"，就能夠開始設定和編輯profile。


3. 選擇"The Witcher 2"，接著在Compatibility(相容性，第一欄)找到SLI compatibility bits，將數值改成 0x02C04205


4. 按下"apply changes"，就大功告成了！


效果如下，首先是全設定最高，開啟UberSampling，解析度是1920x1080：


使用前的狀況(開啟UberSampling)：



使用後的狀況(開啟UberSampling)：



使用後的狀況(關閉UberSampling)：


SLI模式修復後的實際遊戲影片(請用1080p高解析度觀看，全Ultra，測試動態模糊@60FPS)：
http://www.youtube.com/watch?v=7QMaMTtBHI0