Hello xACS Players,
Today, this exciting update has been released on our DarKKO server and will also be valid across all xACS servers.
Let me start by explaining why this update is important.
As you know, we developed our client completely from scratch — unlike other private servers, we do not use the KnightOnline.exe file from USKO or KoreaKO.
This means we’re not affected by their bugs or performance issues because we have no dependencies on them.
Instead, we rebuild all the original features into our own client and server — and we also add our own custom improvements.
This development process has been ongoing for over 2–3 years — just for you.
So why is this update important? Let’s go into detail.
The USKO & KoreaKO clients (essentially the same — so we’ll refer to them as just USKO) have been receiving updates, but they never improve performance at the core.
Most of the game’s functionality runs through the CPU.
That means your FPS doesn’t really benefit from a strong GPU — something USKO players have struggled with for years.
We solved this the moment we started this project.
Many systems were shifted to the GPU side so the game can actually take advantage of your graphics card.
Additionally, we delivered a 64-bit client, which even official servers didn’t have.
This provided smoother gameplay, more FPS, and overall better playability — especially in crowded scenes.
The xACS Client we’ve all been using for years was working with DirectX 9.
It already offered 2–3x more FPS compared to the USKO client, which was great for all of us.
But we decided not to settle.
xACS Client Update – Moving to DirectX 11
Yes, DirectX 11! ^^
With DirectX 11, we’re turning the xACS client from a regular airplane into a space shuttle. ^^
We’re no longer comparing ourselves with USKO.
Let’s compare the previous DirectX 9 version to the new DirectX 11 version of the xACS client.
Note: The following performance results are based on my own system (8700K + 1080Ti), but they give a solid idea of what to expect.
In Moradon Market (the most crowded area), FPS increased by 3–4x:
DirectX 9: 80 FPS
DirectX 11: 300–310 FPS
These results were measured in the most crowded part of the game.
In empty areas, I’ve seen up to 2000–3000 FPS — but what really matters is smooth performance during crowded PK and boss fights.
Disadvantages of the xACS DirectX 11 Update
- Windows XP is no longer supported.
- Systems without DirectX 10/11 compatible GPUs cannot run the client.
- DirectX 9 will still be supported, but only DX10/11 users will benefit from the new performance boost.
Don’t worry — very few of our users fall under this limitation.
Let’s take a look at some Before vs After screenshots
These were taken at the exact same time, place, and angle (06.06.2021 – 20:05).
Thanks to the DX11 update, I’m getting 4x more FPS in the same location.
On a 165Hz monitor, the market area still feels butter smooth.
Before:
After:
Lighting and sun system have also been updated for greater realism
Previously, distant terrain was shown in low quality to save performance.
Now, with the performance boost, even faraway terrain appears in full quality.
We’ve captured the screenshots below from the same spot to show this clearly.
(You can tweak this setting under F10 → Adjust Focus Distance)
Before:
After:
Pay attention to mountain areas — you’ll notice darker shadows on faces not touched by sunlight.
Lighting Improvements (GIF):
Was this update really necessary? Not really.
Even with DirectX 9, xACS had unmatched performance and stability in KO history.
But we keep working hard for our loyal players — to always offer you the best, with the latest features.
By the way, switching from DX9 to DX11 meant rewriting the client from scratch.
They’re completely different worlds.
And still — we did it.
Today, this exciting update has been released on our DarKKO server and will also be valid across all xACS servers.
Let me start by explaining why this update is important.
As you know, we developed our client completely from scratch — unlike other private servers, we do not use the KnightOnline.exe file from USKO or KoreaKO.
This means we’re not affected by their bugs or performance issues because we have no dependencies on them.
Instead, we rebuild all the original features into our own client and server — and we also add our own custom improvements.
This development process has been ongoing for over 2–3 years — just for you.
So why is this update important? Let’s go into detail.
The USKO & KoreaKO clients (essentially the same — so we’ll refer to them as just USKO) have been receiving updates, but they never improve performance at the core.
Most of the game’s functionality runs through the CPU.
That means your FPS doesn’t really benefit from a strong GPU — something USKO players have struggled with for years.
We solved this the moment we started this project.
Many systems were shifted to the GPU side so the game can actually take advantage of your graphics card.
Additionally, we delivered a 64-bit client, which even official servers didn’t have.
This provided smoother gameplay, more FPS, and overall better playability — especially in crowded scenes.
The xACS Client we’ve all been using for years was working with DirectX 9.
It already offered 2–3x more FPS compared to the USKO client, which was great for all of us.
But we decided not to settle.
xACS Client Update – Moving to DirectX 11
Yes, DirectX 11! ^^
With DirectX 11, we’re turning the xACS client from a regular airplane into a space shuttle. ^^
We’re no longer comparing ourselves with USKO.
Let’s compare the previous DirectX 9 version to the new DirectX 11 version of the xACS client.
Note: The following performance results are based on my own system (8700K + 1080Ti), but they give a solid idea of what to expect.
In Moradon Market (the most crowded area), FPS increased by 3–4x:
DirectX 9: 80 FPS
DirectX 11: 300–310 FPS
These results were measured in the most crowded part of the game.
In empty areas, I’ve seen up to 2000–3000 FPS — but what really matters is smooth performance during crowded PK and boss fights.
Disadvantages of the xACS DirectX 11 Update
- Windows XP is no longer supported.
- Systems without DirectX 10/11 compatible GPUs cannot run the client.
- DirectX 9 will still be supported, but only DX10/11 users will benefit from the new performance boost.
Don’t worry — very few of our users fall under this limitation.
Let’s take a look at some Before vs After screenshots
These were taken at the exact same time, place, and angle (06.06.2021 – 20:05).
Thanks to the DX11 update, I’m getting 4x more FPS in the same location.
On a 165Hz monitor, the market area still feels butter smooth.
Before:
After:
Lighting and sun system have also been updated for greater realism
Previously, distant terrain was shown in low quality to save performance.
Now, with the performance boost, even faraway terrain appears in full quality.
We’ve captured the screenshots below from the same spot to show this clearly.
(You can tweak this setting under F10 → Adjust Focus Distance)
Before:
After:
Pay attention to mountain areas — you’ll notice darker shadows on faces not touched by sunlight.
Lighting Improvements (GIF):
Was this update really necessary? Not really.
Even with DirectX 9, xACS had unmatched performance and stability in KO history.
But we keep working hard for our loyal players — to always offer you the best, with the latest features.
By the way, switching from DX9 to DX11 meant rewriting the client from scratch.
They’re completely different worlds.
And still — we did it.
